aboutsummaryrefslogtreecommitdiffstats
path: root/kernel
Commit message (Collapse)AuthorAge
...
| * | | | | | | | | | | | | | | | sched/numa: Initialise numa_next_scan properlyMel Gorman2013-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Scan delay logic and resets are currently initialised to start scanning immediately instead of delaying properly. Initialise them properly at fork time and catch when a new mm has been allocated. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1381141781-10992-17-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | Revert "mm: sched: numa: Delay PTE scanning until a task is scheduled on a ↵Mel Gorman2013-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | new node" PTE scanning and NUMA hinting fault handling is expensive so commit 5bca2303 ("mm: sched: numa: Delay PTE scanning until a task is scheduled on a new node") deferred the PTE scan until a task had been scheduled on another node. The problem is that in the purely shared memory case that this may never happen and no NUMA hinting fault information will be captured. We are not ruling out the possibility that something better can be done here but for now, this patch needs to be reverted and depend entirely on the scan_delay to avoid punishing short-lived processes. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1381141781-10992-16-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | sched/numa: Continue PTE scanning even if migrate rate limitedPeter Zijlstra2013-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Avoiding marking PTEs pte_numa because a particular NUMA node is migrate rate limited sees like a bad idea. Even if this node can't migrate anymore other nodes might and we want up-to-date information to do balance decisions. We already rate limit the actual migrations, this should leave enough bandwidth to allow the non-migrating scanning. I think its important we keep up-to-date information if we're going to do placement based on it. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1381141781-10992-15-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | sched/numa: Mitigate chance that same task always updates PTEsPeter Zijlstra2013-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With a trace_printk("working\n"); right after the cmpxchg in task_numa_work() we can see that of a 4 thread process, its always the same task winning the race and doing the protection change. This is a problem since the task doing the protection change has a penalty for taking faults -- it is busy when marking the PTEs. If its always the same task the ->numa_faults[] get severely skewed. Avoid this by delaying the task doing the protection change such that it is unlikely to win the privilege again. Before: root@interlagos:~# grep "thread 0/.*working" /debug/tracing/trace | tail -15 thread 0/0-3232 [022] .... 212.787402: task_numa_work: working thread 0/0-3232 [022] .... 212.888473: task_numa_work: working thread 0/0-3232 [022] .... 212.989538: task_numa_work: working thread 0/0-3232 [022] .... 213.090602: task_numa_work: working thread 0/0-3232 [022] .... 213.191667: task_numa_work: working thread 0/0-3232 [022] .... 213.292734: task_numa_work: working thread 0/0-3232 [022] .... 213.393804: task_numa_work: working thread 0/0-3232 [022] .... 213.494869: task_numa_work: working thread 0/0-3232 [022] .... 213.596937: task_numa_work: working thread 0/0-3232 [022] .... 213.699000: task_numa_work: working thread 0/0-3232 [022] .... 213.801067: task_numa_work: working thread 0/0-3232 [022] .... 213.903155: task_numa_work: working thread 0/0-3232 [022] .... 214.005201: task_numa_work: working thread 0/0-3232 [022] .... 214.107266: task_numa_work: working thread 0/0-3232 [022] .... 214.209342: task_numa_work: working After: root@interlagos:~# grep "thread 0/.*working" /debug/tracing/trace | tail -15 thread 0/0-3253 [005] .... 136.865051: task_numa_work: working thread 0/2-3255 [026] .... 136.965134: task_numa_work: working thread 0/3-3256 [024] .... 137.065217: task_numa_work: working thread 0/3-3256 [024] .... 137.165302: task_numa_work: working thread 0/3-3256 [024] .... 137.265382: task_numa_work: working thread 0/0-3253 [004] .... 137.366465: task_numa_work: working thread 0/2-3255 [026] .... 137.466549: task_numa_work: working thread 0/0-3253 [004] .... 137.566629: task_numa_work: working thread 0/0-3253 [004] .... 137.666711: task_numa_work: working thread 0/1-3254 [028] .... 137.766799: task_numa_work: working thread 0/0-3253 [004] .... 137.866876: task_numa_work: working thread 0/2-3255 [026] .... 137.966960: task_numa_work: working thread 0/1-3254 [028] .... 138.067041: task_numa_work: working thread 0/2-3255 [026] .... 138.167123: task_numa_work: working thread 0/3-3256 [024] .... 138.267207: task_numa_work: working Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1381141781-10992-14-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | sched/numa: Fix commentsPeter Zijlstra2013-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix a 80 column violation and a PTE vs PMD reference. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1381141781-10992-4-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | Merge tag 'v3.12-rc4' into sched/coreIngo Molnar2013-10-09
| |\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ | | | |_|_|_|_|_|_|/ / / / / / / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge Linux v3.12-rc4 to fix a conflict and also to refresh the tree before applying more scheduler patches. Conflicts: arch/avr32/include/asm/Kbuild Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | sched/rt: Remove redundant nr_cpus_allowed testShawn Bohrer2013-10-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In 76854c7e8f3f4172fef091e78d88b3b751463ac6 ("sched: Use rt.nr_cpus_allowed to recover select_task_rq() cycles") an optimization was added to select_task_rq_rt() that immediately returns when p->nr_cpus_allowed == 1 at the beginning of the function. This makes the latter p->nr_cpus_allowed > 1 check redundant, which can now be removed. Signed-off-by: Shawn Bohrer <sbohrer@rgmadvisors.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Mike Galbraith <mgalbraith@suse.de> Cc: tomk@rgmadvisors.com Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1380914693-24634-1-git-send-email-shawn.bohrer@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | sched: Prepare for per-cpu preempt_countPeter Zijlstra2013-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When using per-cpu preempt_count variables we need to save/restore the preempt_count on context switch (into per task storage; for instance the old thread_info::preempt_count variable) because of PREEMPT_ACTIVE. However, this means that on fork() the preempt_count value of the last context switch gets copied and if we had a PREEMPT_ACTIVE switch right before cloning a child task the child task will now too have PREEMPT_ACTIVE set and start its life with an extra PREEMPT_ACTIVE count. Therefore we need to make init_task_preempt_count() unconditional; this resets whatever preempt_count we inherited from our parent process. Doing so for !per-cpu implementations is harmless. For !PREEMPT_COUNT kernels we need to be careful not to start life with an increased preempt_count. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-4k0b7oy1rcdyzochwiixuwi9@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | sched: Extract the basic add/sub preempt_count modifiersPeter Zijlstra2013-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rewrite the preempt_count macros in order to extract the 3 basic preempt_count value modifiers: __preempt_count_add() __preempt_count_sub() and the new: __preempt_count_dec_and_test() And since we're at it anyway, replace the unconventional $op_preempt_count names with the more conventional preempt_count_$op. Since these basic operators are equivalent to the previous _notrace() variants, do away with the _notrace() versions. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-ewbpdbupy9xpsjhg960zwbv8@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | sched: Create more preempt_count accessorsPeter Zijlstra2013-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need a few special preempt_count accessors: - task_preempt_count() for when we're interested in the preemption count of another (non-running) task. - init_task_preempt_count() for properly initializing the preemption count. - init_idle_preempt_count() a special case of the above for the idle threads. With these no generic code ever touches thread_info::preempt_count anymore and architectures could choose to remove it. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-jf5swrio8l78j37d06fzmo4r@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | sched: Add NEED_RESCHED to the preempt_countPeter Zijlstra2013-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to combine the preemption and need_resched test we need to fold the need_resched information into the preempt_count value. Since the NEED_RESCHED flag is set across CPUs this needs to be an atomic operation, however we very much want to avoid making preempt_count atomic, therefore we keep the existing TIF_NEED_RESCHED infrastructure in place but at 3 sites test it and fold its value into preempt_count; namely: - resched_task() when setting TIF_NEED_RESCHED on the current task - scheduler_ipi() when resched_task() sets TIF_NEED_RESCHED on a remote task it follows it up with a reschedule IPI and we can modify the cpu local preempt_count from there. - cpu_idle_loop() for when resched_task() found tsk_is_polling(). We use an inverted bitmask to indicate need_resched so that a 0 means both need_resched and !atomic. Also remove the barrier() in preempt_enable() between preempt_enable_no_resched() and preempt_check_resched() to avoid having to reload the preemption value and allow the compiler to use the flags of the previuos decrement. I couldn't come up with any sane reason for this barrier() to be there as preempt_enable_no_resched() already has a barrier() before doing the decrement. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-7a7m5qqbn5pmwnd4wko9u6da@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | sched: Introduce preempt_count accessor functionsPeter Zijlstra2013-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace the single preempt_count() 'function' that's an lvalue with two proper functions: preempt_count() - returns the preempt_count value as rvalue preempt_count_set() - Allows setting the preempt-count value Also provide preempt_count_ptr() as a convenience wrapper to implement all modifying operations. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-orxrbycjozopqfhb4dxdkdvb@git.kernel.org [ Fixed build failure. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | sched, idle: Fix the idle polling state logicPeter Zijlstra2013-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mike reported that commit 7d1a9417 ("x86: Use generic idle loop") regressed several workloads and caused excessive reschedule interrupts. The patch in question failed to notice that the x86 code had an inverted sense of the polling state versus the new generic code (x86: default polling, generic: default !polling). Fix the two prominent x86 mwait based idle drivers and introduce a few new generic polling helpers (fixing the wrong smp_mb__after_clear_bit usage). Also switch the idle routines to using tif_need_resched() which is an immediate TIF_NEED_RESCHED test as opposed to need_resched which will end up being slightly different. Reported-by: Mike Galbraith <bitbucket@online.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: lenb@kernel.org Cc: tglx@linutronix.de Link: http://lkml.kernel.org/n/tip-nc03imb0etuefmzybzj7sprf@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | sched, rcu: Make RCU use resched_cpu()Peter Zijlstra2013-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We're going to deprecate and remove set_need_resched() for it will do the wrong thing. Make an exception for RCU and allow it to use resched_cpu() which will do the right thing. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/n/tip-2eywnacjl1nllctl1nszqa5w@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | sched: Micro-optimize by dropping unnecessary task_rq() callsMichael S. Tsirkin2013-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We always know the rq used, let's just pass it around. This seems to cut the size of scheduler core down a tiny bit: Before: [linux]$ size kernel/sched/core.o.orig text data bss dec hex filename 62760 16130 3876 82766 1434e kernel/sched/core.o.orig After: [linux]$ size kernel/sched/core.o.patched text data bss dec hex filename 62566 16130 3876 82572 1428c kernel/sched/core.o.patched Probably speeds it up as well. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20130922142054.GA11499@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | sched/balancing: Periodically decay max cost of idle balanceJason Low2013-09-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch builds on patch 2 and periodically decays that max value to do idle balancing per sched domain by approximately 1% per second. Also decay the rq's max_idle_balance_cost value. Signed-off-by: Jason Low <jason.low2@hp.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1379096813-3032-4-git-send-email-jason.low2@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | sched/balancing: Consider max cost of idle balance per sched domainJason Low2013-09-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In this patch, we keep track of the max cost we spend doing idle load balancing for each sched domain. If the avg time the CPU remains idle is less then the time we have already spent on idle balancing + the max cost of idle balancing in the sched domain, then we don't continue to attempt the balance. We also keep a per rq variable, max_idle_balance_cost, which keeps track of the max time spent on newidle load balances throughout all its domains so that we can determine the avg_idle's max value. By using the max, we avoid overrunning the average. This further reduces the chance we attempt balancing when the CPU is not idle for longer than the cost to balance. Signed-off-by: Jason Low <jason.low2@hp.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1379096813-3032-3-git-send-email-jason.low2@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | sched: Reduce overestimating rq->avg_idleJason Low2013-09-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When updating avg_idle, if the delta exceeds some max value, then avg_idle gets set to the max, regardless of what the previous avg was. This can cause avg_idle to often be overestimated. This patch modifies the way we update avg_idle by always updating it with the function call to update_avg() first. Then, if avg_idle exceeds the max, we set it to the max. Signed-off-by: Jason Low <jason.low2@hp.com> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1379096813-3032-2-git-send-email-jason.low2@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | sched/balancing: Prevent the reselection of a previous env.dst_cpu if some ↵Vladimir Davydov2013-09-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tasks are pinned Currently new_dst_cpu is prevented from being reselected actually, not dst_cpu. This can result in attempting to pull tasks to this_cpu twice. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/281f59b6e596c718dd565ad267fc38f5b8e5c995.1379265590.git.vdavydov@parallels.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | Merge branch 'sched/urgent' into sched/coreIngo Molnar2013-09-20
| |\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge in the latest fixes before applying a dependent patch. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | sched/fair: Fix the group_capacity computationPeter Zijlstra2013-09-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Do away with 'phantom' cores due to N*frac(smt_power) >= 1 by limiting the capacity to the actual number of cores. The assumption of 1 < smt_power < 2 is an actual requirement because of what SMT is so this should work regardless of the SMT implementation. It can still be defeated by creative use of cpu hotplug, but if you're one of those freaks, you get to live with it. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Vincent Guittot <vincent.guitto@linaro.org> Link: http://lkml.kernel.org/n/tip-dczmbi8tfgixacg1ji2av1un@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | sched/fair: Rework and comment the group_capacity codePeter Zijlstra2013-09-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull out the group_capacity computation so that we can more clearly comment its issues. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-az1hl1ya55k361nkeh9bj0yw@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | sched/fair: Fix group power_orig computationPeter Zijlstra2013-09-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When looking at the code I noticed we don't actually compute sgp->power_orig correctly for groups, fix that. Currently the only consumer of that value is fix_small_capacity() which is only used on POWER7+ and that code excludes this case by being limited to SD_SHARE_CPUPOWER which is only ever set on the SMT domain which must be the lowest domain and this has singleton groups. So nothing should be affected by this change. Cc: Michael Neuling <mikey@neuling.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-db2pe0vxwunv37plc7onnugj@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | sched/fair: Reduce local_group logicPeter Zijlstra2013-09-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Try and reduce the local_group logic by pulling most of it into update_sd_lb_stats. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-mgezl354xgyhiyrte78fdkpd@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | sched/fair: Rewrite group_imb triggerPeter Zijlstra2013-09-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change the group_imb detection from the old 'load-spike' detector to an actual imbalance detector. We set it from the lower domain balance pass when it fails to create a balance in the presence of task affinities. The advantage is that this should no longer generate the false positive group_imb conditions generated by transient load spikes from the normal balancing/bulk-wakeup etc. behaviour. While I haven't actually observed those they could happen. I'm not entirely happy with this patch; it somehow feels a little fragile. Nor does it solve the biggest issue I have with the group_imb code; it it still a fragile construct in that once we 'fixed' the imbalance we'll not detect the group_imb again and could end up re-creating it. That said, this patch does seem to preserve behaviour for the described degenerate case. In particular on my 2*6*2 wsm-ep: taskset -c 3-11 bash -c 'for ((i=0;i<9;i++)) do while :; do :; done & done' ends up with 9 spinners, each on their own CPU; whereas if you disable the group_imb code that typically doesn't happen (you'll get one pair sharing a CPU most of the time). Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-36fpbgl39dv4u51b6yz2ypz5@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | | | | | | | | | | | | Merge branch 'perf-core-for-linus' of ↵Linus Torvalds2013-11-11
|\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "As a first remark I'd like to note that the way to build perf tooling has been simplified and sped up, in the future it should be enough for you to build perf via: cd tools/perf/ make install (ie without the -j option.) The build system will figure out the number of CPUs and will do a parallel build+install. The various build system inefficiencies and breakages Linus reported against the v3.12 pull request should now be resolved - please (re-)report any remaining annoyances or bugs. Main changes on the perf kernel side: * Performance optimizations: . perf ring-buffer code optimizations, by Peter Zijlstra . perf ring-buffer code optimizations, by Oleg Nesterov . x86 NMI call-stack processing optimizations, by Peter Zijlstra . perf context-switch optimizations, by Peter Zijlstra . perf sampling speedups, by Peter Zijlstra . x86 Intel PEBS processing speedups, by Peter Zijlstra * Enhanced hardware support: . for Intel Ivy Bridge-EP uncore PMUs, by Zheng Yan . for Haswell transactions, by Andi Kleen, Peter Zijlstra * Core perf events code enhancements and fixes by Oleg Nesterov: . for uprobes, if fork() is called with pending ret-probes . for uprobes platform support code * New ABI details by Andi Kleen: . Report x86 Haswell TSX transaction abort cost as weight Main changes on the perf tooling side (some of these tooling changes utilize the above kernel side changes): * 'perf report/top' enhancements: . Convert callchain children list to rbtree, greatly reducing the time taken for callchain processing, from Namhyung Kim. . Add new COMM infrastructure, further improving histogram processing, from Frédéric Weisbecker, one fix from Namhyung Kim. . Add /proc/kcore based live-annotation improvements, including build-id cache support, multi map 'call' instruction navigation fixes, kcore address validation, objdump workarounds. From Adrian Hunter. . Show progress on histogram collapsing, that can take a long time, from Namhyung Kim. . Add --max-stack option to limit callchain stack scan in 'top' and 'report', improving callchain processing when reducing the stack depth is an option, from Waiman Long. . Add new option --ignore-vmlinux for perf top, from Willy Tarreau. * 'perf trace' enhancements: . 'perf trace' now can can use a 'perf probe' dynamic tracepoints to hook into the userspace -> kernel pathname copy so that it can map fds to pathnames without reading /proc/pid/fd/ symlinks. From Arnaldo Carvalho de Melo. . Show VFS path associated with fd in live sessions, using a 'vfs_getname' 'perf probe' created dynamic tracepoint or by looking at /proc/pid/fd, from Arnaldo Carvalho de Melo. . Add 'trace' beautifiers for lots of syscall arguments, from Arnaldo Carvalho de Melo. . Implement more compact 'trace' output by suppressing zeroed args, from Arnaldo Carvalho de Melo. . Show thread COMM by default in 'trace', from Arnaldo Carvalho de Melo. . Add option to show full timestamp in 'trace', from David Ahern. . Add 'record' command in 'trace', to record raw_syscalls:*, from David Ahern. . Add summary option to dump syscall statistics in 'trace', from David Ahern. . Improve error messages in 'trace', providing hints about system configuration steps needed for using it, from Ramkumar Ramachandra. . 'perf trace' now emits hints as to why tracing is not possible, helping the user to setup the system to allow tracing in the desired permission granularity, telling if the problem is due to debugfs not being mounted or with not enough permission for !root, /proc/sys/kernel/perf_event_paranoit value, etc. From Arnaldo Carvalho de Melo. * 'perf record' enhancements: . Check maximum frequency rate for record/top, emitting better error messages, from Jiri Olsa. . 'perf record' code cleanups, from David Ahern. . Improve write_output error message in 'perf record', from Adrian Hunter. . Allow specifying B/K/M/G unit to the --mmap-pages arguments, from Jiri Olsa. . Fix command line callchain attribute tests to handle the new -g/--call-chain semantics, from Arnaldo Carvalho de Melo. * 'perf kvm' enhancements: . Disable live kvm command if timerfd is not supported, from David Ahern. . Fix detection of non-core features, from David Ahern. * 'perf list' enhancements: . Add usage to 'perf list', from David Ahern. . Show error in 'perf list' if tracepoints not available, from Pekka Enberg. * 'perf probe' enhancements: . Support "$vars" meta argument syntax for local variables, allowing asking for all possible variables at a given probe point to be collected when it hits, from Masami Hiramatsu. * 'perf sched' enhancements: . Address the root cause of that 'perf sched' stack initialization build slowdown, by programmatically setting a big array after moving the global variable back to the stack. Fix from Adrian Hunter. * 'perf script' enhancements: . Set up output options for in-stream attributes, from Adrian Hunter. . Print addr by default for BTS in 'perf script', from Adrian Juntmer * 'perf stat' enhancements: . Improved messages when doing profiling in all or a subset of CPUs using a workload as the session delimitator, as in: 'perf stat --cpu 0,2 sleep 10s' from Arnaldo Carvalho de Melo. . Add units to nanosec-based counters in 'perf stat', from David Ahern. . Remove bogus info when using 'perf stat' -e cycles/instructions, from Ramkumar Ramachandra. * 'perf lock' enhancements: . 'perf lock' fixes and cleanups, from Davidlohr Bueso. * 'perf test' enhancements: . Fixup PERF_SAMPLE_TRANSACTION handling in sample synthesizing and 'perf test', from Adrian Hunter. . Clarify the "sample parsing" test entry, from Arnaldo Carvalho de Melo. . Consider PERF_SAMPLE_TRANSACTION in the "sample parsing" test, from Arnaldo Carvalho de Melo. . Memory leak fixes in 'perf test', from Felipe Pena. * 'perf bench' enhancements: . Change the procps visible command-name of invididual benchmark tests plus cleanups, from Ingo Molnar. * Generic perf tooling infrastructure/plumbing changes: . Separating data file properties from session, code reorganization from Jiri Olsa. . Fix version when building out of tree, as when using one of these: $ make help | grep perf perf-tar-src-pkg - Build perf-3.12.0.tar source tarball perf-targz-src-pkg - Build perf-3.12.0.tar.gz source tarball perf-tarbz2-src-pkg - Build perf-3.12.0.tar.bz2 source tarball perf-tarxz-src-pkg - Build perf-3.12.0.tar.xz source tarball $ from David Ahern. . Enhance option parse error message, showing just the help lines of the options affected, from Namhyung Kim. . libtraceevent updates from upstream trace-cmd repo, from Steven Rostedt. . Always use perf_evsel__set_sample_bit to set sample_type, from Adrian Hunter. . Memory and mmap leak fixes from Chenggang Qin. . Assorted build fixes for from David Ahern and Jiri Olsa. . Speed up and prettify the build system, from Ingo Molnar. . Implement addr2line directly using libbfd, from Roberto Vitillo. . Separate the GTK support in a separate libperf-gtk.so DSO, that is only loaded when --gtk is specified, from Namhyung Kim. . perf bash completion fixes and improvements from Ramkumar Ramachandra. . Support for Openembedded/Yocto -dbg packages, from Ricardo Ribalda Delgado. And lots and lots of other fixes and code reorganizations that did not make it into the list, see the shortlog, diffstat and the Git log for details!" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (300 commits) uprobes: Fix the memory out of bound overwrite in copy_insn() uprobes: Fix the wrong usage of current->utask in uprobe_copy_process() perf tools: Remove unneeded include perf record: Remove post_processing_offset variable perf record: Remove advance_output function perf record: Refactor feature handling into a separate function perf trace: Don't relookup fields by name in each sample perf tools: Fix version when building out of tree perf evsel: Ditch evsel->handler.data field uprobes: Export write_opcode() as uprobe_write_opcode() uprobes: Introduce arch_uprobe->ixol uprobes: Kill module_init() and module_exit() uprobes: Move function declarations out of arch perf/x86/intel: Add Ivy Bridge-EP uncore IRP box support perf/x86/intel/uncore: Add filter support for IvyBridge-EP QPI boxes perf: Factor out strncpy() in perf_event_mmap_event() tools/perf: Add required memory barriers perf: Fix arch_perf_out_copy_user default perf: Update a stale comment perf: Optimize perf_output_begin() -- address calculation ...
| * | | | | | | | | | | | | | | | | | uprobes: Fix the memory out of bound overwrite in copy_insn()Oleg Nesterov2013-11-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1. copy_insn() doesn't look very nice, all calculations are confusing and it is not immediately clear why do we read the 2nd page first. 2. The usage of inode->i_size is wrong on 32-bit machines. 3. "Instruction at end of binary" logic is simply wrong, it doesn't handle the case when uprobe->offset > inode->i_size. In this case "bytes" overflows, and __copy_insn() writes to the memory outside of uprobe->arch.insn. Yes, uprobe_register() checks i_size_read(), but this file can be truncated after that. All i_size checks are racy, we do this only to catch the obvious mistakes. Change copy_insn() to call __copy_insn() in a loop, simplify and fix the bytes/nbytes calculations. Note: we do not care if we read extra bytes after inode->i_size if we got the valid page. This is fine because the task gets the same page after page-fault, and arch_uprobe_analyze_insn() can't know how many bytes were actually read anyway. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| * | | | | | | | | | | | | | | | | | uprobes: Fix the wrong usage of current->utask in uprobe_copy_process()Oleg Nesterov2013-11-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit aa59c53fd459 "uprobes: Change uprobe_copy_process() to dup xol_area" has a stupid typo, we need to setup t->utask->vaddr but the code wrongly uses current->utask. Even with this bug dup_xol_work() works "in practice", but only because get_unmapped_area(NULL, TASK_SIZE - PAGE_SIZE) likely returns the same address every time. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| * | | | | | | | | | | | | | | | | | uprobes: Export write_opcode() as uprobe_write_opcode()Oleg Nesterov2013-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | set_swbp() and set_orig_insn() are __weak, but this is pointless because write_opcode() is static. Export write_opcode() as uprobe_write_opcode() for the upcoming arm port, this way it can actually override set_swbp() and use __opcode_to_mem_arm(bpinsn) instead if UPROBE_SWBP_INSN. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| * | | | | | | | | | | | | | | | | | uprobes: Introduce arch_uprobe->ixolOleg Nesterov2013-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently xol_get_insn_slot() assumes that we should simply copy arch_uprobe->insn[] which is (ignoring arch_uprobe_analyze_insn) just the copy of the original insn. This is not true for arm which needs to create another insn to execute it out-of-line. So this patch simply adds the new member, ->ixol into the union. This doesn't make any difference for x86 and powerpc, but arm can divorce insn/ixol and initialize the correct xol insn in arch_uprobe_analyze_insn(). Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| * | | | | | | | | | | | | | | | | | uprobes: Kill module_init() and module_exit()Oleg Nesterov2013-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Turn module_init() into __initcall() and kill module_exit(). This code can't be compiled as a module so these module_*() calls only add the confusion, especially if arch-dependant code needs its own initialization hooks. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| * | | | | | | | | | | | | | | | | | perf: Factor out strncpy() in perf_event_mmap_event()Oleg Nesterov2013-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While this is really minor, but strncpy() does the unnecessary zero-padding till the end of tmp[16] and it is called every time we are going to use the string literal. Turn these strncpy()'s into the single strlcpy() under the new label, saves 72 bytes. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20131017182417.GA17753@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | | perf: Fix arch_perf_out_copy_user defaultPeter Zijlstra2013-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The arch_perf_output_copy_user() default of __copy_from_user_inatomic() returns bytes not copied, while all other argument functions given DEFINE_OUTPUT_COPY() return bytes copied. Since copy_from_user_nmi() is the odd duck out by returning bytes copied where all other *copy_{to,from}* functions return bytes not copied, change it over and ammend DEFINE_OUTPUT_COPY() to expect bytes not copied. Oddly enough DEFINE_OUTPUT_COPY() already returned bytes not copied while expecting its worker functions to return bytes copied. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: will.deacon@arm.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20131030201622.GR16117@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | | perf: Update a stale commentPeter Zijlstra2013-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Michael Neuling <mikey@neuling.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: james.hogan@imgtec.com Cc: Vince Weaver <vince@deater.net> Cc: Victor Kaplansky <VICTORK@il.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Anton Blanchard <anton@samba.org> Link: http://lkml.kernel.org/n/tip-9s5mze78gmlz19agt39i8rii@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | | perf: Optimize perf_output_begin() -- address calculationPeter Zijlstra2013-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rewrite the handle address calculation code to be clearer. Saves 8 bytes on x86_64-defconfig. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Michael Neuling <mikey@neuling.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: james.hogan@imgtec.com Cc: Vince Weaver <vince@deater.net> Cc: Victor Kaplansky <VICTORK@il.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Anton Blanchard <anton@samba.org> Link: http://lkml.kernel.org/n/tip-3trb2n2henb9m27tncef3ag7@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | | perf: Optimize perf_output_begin() -- lost_event casePeter Zijlstra2013-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Avoid touching the lost_event and sample_data cachelines twince. Its not like we end up doing less work, but it might help to keep all accesses to these cachelines in one place. Due to code shuffle, this looses 4 bytes on x86_64-defconfig. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Michael Neuling <mikey@neuling.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: james.hogan@imgtec.com Cc: Vince Weaver <vince@deater.net> Cc: Victor Kaplansky <VICTORK@il.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Anton Blanchard <anton@samba.org> Link: http://lkml.kernel.org/n/tip-zfxnc58qxj0eawdoj31hhupv@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | | perf: Optimize perf_output_begin()Peter Zijlstra2013-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's no point in re-doing the memory-barrier when we fail the cmpxchg(). Also placing it after the space reservation loop makes it clearer it only separates the userpage->tail read from the data stores. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Michael Neuling <mikey@neuling.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: james.hogan@imgtec.com Cc: Vince Weaver <vince@deater.net> Cc: Victor Kaplansky <VICTORK@il.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Anton Blanchard <anton@samba.org> Link: http://lkml.kernel.org/n/tip-c19u6egfldyx86tpyc3zgkw9@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | | perf: Add unlikely() to the ring-buffer codePeter Zijlstra2013-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add unlikely() annotations to 'slow' paths: When having a sampling event but no output buffer; you have bigger issues -- also the bail is still faster than actually doing the work. When having a sampling event but a control page only buffer, you have bigger issues -- again the bail is still faster than actually doing work. Optimize for the case where you're not loosing events -- again, not doing the work is still faster but make sure that when you have to actually do work its as fast as possible. The typical watermark is 1/2 the buffer size, so most events will not take this path. Shrinks perf_output_begin() by 16 bytes on x86_64-defconfig. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Michael Neuling <mikey@neuling.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: james.hogan@imgtec.com Cc: Vince Weaver <vince@deater.net> Cc: Victor Kaplansky <VICTORK@il.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Anton Blanchard <anton@samba.org> Link: http://lkml.kernel.org/n/tip-wlg3jew3qnutm8opd0hyeuwn@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | | perf: Simplify the ring-buffer codePeter Zijlstra2013-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | By using CIRC_SPACE() we can obviate the need for perf_output_space(). Shrinks the size of perf_output_begin() by 17 bytes on x86_64-defconfig. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Michael Neuling <mikey@neuling.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: james.hogan@imgtec.com Cc: Vince Weaver <vince@deater.net> Cc: Victor Kaplansky <VICTORK@il.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Anton Blanchard <anton@samba.org> Link: http://lkml.kernel.org/n/tip-vtb0xb0llebmsdlfn1v5vtfj@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | | Merge branch 'perf/urgent' into perf/core to fix conflictsIngo Molnar2013-11-04
| |\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ | | | |_|_|_|_|_|_|_|_|_|_|_|/ / / / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: tools/perf/bench/numa.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | | uprobes: Teach uprobe_copy_process() to handle CLONE_VFORKOleg Nesterov2013-10-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | uprobe_copy_process() does nothing if the child shares ->mm with the forking process, but there is a special case: CLONE_VFORK. In this case it would be more correct to do dup_utask() but avoid dup_xol(). This is not that important, the child should not unwind its stack too much, this can corrupt the parent's stack, but at least we need this to allow to ret-probe __vfork() itself. Note: in theory, it would be better to check task_pt_regs(p)->sp instead of CLONE_VFORK, we need to dup_utask() if and only if the child can return from the function called by the parent. But this needs the arch-dependant helper, and I think that nobody actually does clone(same_stack, CLONE_VM). Reported-by: Martin Cermak <mcermak@redhat.com> Reported-by: David Smith <dsmith@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| * | | | | | | | | | | | | | | | | | uprobes: Change uprobe_copy_process() to dup xol_areaOleg Nesterov2013-10-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This finally fixes the serious bug in uretprobes: a forked child crashes if the parent called fork() with the pending ret probe. Trivial test-case: # perf probe -x /lib/libc.so.6 __fork%return # perf record -e probe_libc:__fork perl -le 'fork || print "OK"' (the child doesn't print "OK", it is killed by SIGSEGV) If the child returns from the probed function it actually returns to trampoline_vaddr, because it got the copy of parent's stack mangled by prepare_uretprobe() when the parent entered this func. It crashes because a) this address is not mapped and b) until the previous change it doesn't have the proper->return_instances info. This means that uprobe_copy_process() has to create xol_area which has the trampoline slot, and its vaddr should be equal to parent's xol_area->vaddr. Unfortunately, uprobe_copy_process() can not simply do __create_xol_area(child, xol_area->vaddr). This could actually work but perf_event_mmap() doesn't expect the usage of foreign ->mm. So we offload this to task_work_run(), and pass the argument via not yet used utask->vaddr. We know that this vaddr is fine for install_special_mapping(), the necessary hole was recently "created" by dup_mmap() which skips the parent's VM_DONTCOPY area, and nobody else could use the new mm. Unfortunately, this also means that we can not handle the errors properly, we obviously can not abort the already completed fork(). So we simply print the warning if GFP_KERNEL allocation (the only possible reason) fails. Reported-by: Martin Cermak <mcermak@redhat.com> Reported-by: David Smith <dsmith@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | | | | | | | | | | | | | | | | | uprobes: Change uprobe_copy_process() to dup return_instancesOleg Nesterov2013-10-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | uprobe_copy_process() assumes that the new child doesn't need ->utask, it should be allocated by demand. But this is not true if the forking task has the pending ret- probes, the child should report them as well and thus it needs the copy of parent's ->return_instances chain. Otherwise the child crashes when it returns from the probed function. Alternatively we could cleanup the child's stack, but this needs per-arch changes and this is not what we want. At least systemtap expects a .return in the child too. Note: this change alone doesn't fix the problem, see the next change. Reported-by: Martin Cermak <mcermak@redhat.com> Reported-by: David Smith <dsmith@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | | | | | | | | | | | | | | | | | uprobes: Teach __create_xol_area() to accept the predefined vaddrOleg Nesterov2013-10-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently xol_add_vma() uses get_unmapped_area() for area->vaddr, but the next patches need to use the fixed address. So this patch adds the new "vaddr" argument to __create_xol_area() which should be used as area->vaddr if it is nonzero. xol_add_vma() doesn't bother to verify that the predefined addr is not used, insert_vm_struct() should fail if find_vma_links() detects the overlap with the existing vma. Also, __create_xol_area() doesn't need __GFP_ZERO to allocate area. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | | | | | | | | | | | | | | | | | uprobes: Introduce __create_xol_area()Oleg Nesterov2013-10-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No functional changes, preparation. Extract the code which actually allocates/installs the new area into the new helper, __create_xol_area(). While at it remove the unnecessary "ret = ENOMEM" and "ret = 0" in xol_add_vma(), they both have no effect. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | | | | | | | | | | | | | | | | | uprobes: Change the callsite of uprobe_copy_process()Oleg Nesterov2013-10-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Preparation for the next patches. Move the callsite of uprobe_copy_process() in copy_process() down to the succesfull return. We do not care if copy_process() fails, uprobe_free_utask() won't be called in this case so the wrong ->utask != NULL doesn't matter. OTOH, with this change we know that copy_process() can't fail when uprobe_copy_process() is called, the new task should either return to user-mode or call do_exit(). This way uprobe_copy_process() can: 1. setup p->utask != NULL if necessary 2. setup uprobes_state.xol_area 3. use task_work_add(p) Also, move the definition of uprobe_copy_process() down so that it can see get_utask(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | | | | | | | | | | | | | | | | | perf: Fix the perf context switch optimizationPeter Zijlstra2013-10-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we only optimize the context switch between two contexts that have the same parent; this forgoes the optimization between parent and child context, even though these contexts could be equivalent too. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Shishkin, Alexander <alexander.shishkin@intel.com> Link: http://lkml.kernel.org/r/20131007164257.GH3081@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | | perf: Change zero-padding of strings in perf_event_mmap_event()Peter Zijlstra2013-10-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Oleg complained about the excessive 0-ing in perf_event_mmap_event(), so try and be smarter about it while keeping it fairly fool proof and avoid leaking random bits out to userspace. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-8jirlm99m6if2z13wd6rbyu6@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | | perf: Do not waste PAGE_SIZE bytes for ALIGN(8) in perf_event_mmap_event()Oleg Nesterov2013-10-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | perf_event_mmap_event() does kzalloc(PATH_MAX + sizeof(u64)) to ensure we can align the size later. However this means that we actually allocate PAGE_SIZE * 2 buffer, seems too much. Change this code to allocate PATH_MAX==PAGE_SIZE bytes, but tell d_path() to not use the last sizeof(u64) bytes. Note: it is not clear why do we need __GFP_ZERO, see the next patch. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20131016201004.GC23214@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | | | | | perf: Kill the dead !vma->vm_mm code in perf_event_mmap_event()Oleg Nesterov2013-10-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1. perf_event_mmap(vma) is never called with a gate_vma-like arg, remove the "if (!vma->vm_mm)" code. 2. arch_vma_name() can use the chached value of mmap_event->vma. 3. Change the code to not call arch_vma_name() twice. 4. Purely cosmetic, but since we use "goto got_name" all the time remove "else" from "[stack]" branch just for symmetry. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20131016200945.GB23214@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>