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* printk: Use this_cpu_{read|write} api on printk_pendingEric Dumazet2010-12-08
| | | | | | | | | | | | | | | | | | | | | | | __get_cpu_var() is a bit inefficient, lets use __this_cpu_read() and __this_cpu_write() to manipulate printk_pending. printk_needs_cpu(cpu) is called only for the current cpu : Use faster __this_cpu_read(). Remove the redundant unlikely on (cpu_is_offline(cpu)) test: # size kernel/printk.o* text data bss dec hex filename 9942 756 263488 274186 42f0a kernel/printk.o.new 9990 756 263488 274234 42f3a kernel/printk.o.old Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1290788536.2855.237.camel@edumazet-laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: Make pushable_tasks CONFIG_SMP dependantDario Faggioli2010-12-08
| | | | | | | | | | | | | As noted by Peter Zijlstra at https://lkml.org/lkml/2010/11/10/391 (while reviewing other stuff, though), tracking pushable tasks only makes sense on SMP systems. Signed-off-by: Dario Faggioli <raistlin@linux.it> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1291143093.2697.298.camel@Palantir> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'linus' into sched/coreIngo Molnar2010-12-08
|\ | | | | | | | | | | Merge reason: we want to queue up dependent cleanup Signed-off-by: Ingo Molnar <mingo@elte.hu>
| *---. Merge branches 'x86-fixes-for-linus', 'perf-fixes-for-linus' and ↵Linus Torvalds2010-12-08
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86/pvclock: Zero last_value on resume * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf record: Fix eternal wait for stillborn child perf header: Don't assume there's no attr info if no sample ids is provided perf symbols: Figure out start address of kernel map from kallsyms perf symbols: Fix kallsyms kernel/module map splitting * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: nohz: Fix printk_needs_cpu() return value on offline cpus printk: Fix wake_up_klogd() vs cpu hotplug
| | | | * nohz: Fix printk_needs_cpu() return value on offline cpusHeiko Carstens2010-11-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes a hang observed with 2.6.32 kernels where timers got enqueued on offline cpus. printk_needs_cpu() may return 1 if called on offline cpus. When a cpu gets offlined it schedules the idle process which, before killing its own cpu, will call tick_nohz_stop_sched_tick(). That function in turn will call printk_needs_cpu() in order to check if the local tick can be disabled. On offline cpus this function should naturally return 0 since regardless if the tick gets disabled or not the cpu will be dead short after. That is besides the fact that __cpu_disable() should already have made sure that no interrupts on the offlined cpu will be delivered anyway. In this case it prevents tick_nohz_stop_sched_tick() to call select_nohz_load_balancer(). No idea if that really is a problem. However what made me debug this is that on 2.6.32 the function get_nohz_load_balancer() is used within __mod_timer() to select a cpu on which a timer gets enqueued. If printk_needs_cpu() returns 1 then the nohz_load_balancer cpu doesn't get updated when a cpu gets offlined. It may contain the cpu number of an offline cpu. In turn timers get enqueued on an offline cpu and not very surprisingly they never expire and cause system hangs. This has been observed 2.6.32 kernels. On current kernels __mod_timer() uses get_nohz_timer_target() which doesn't have that problem. However there might be other problems because of the too early exit tick_nohz_stop_sched_tick() in case a cpu goes offline. Easiest way to fix this is just to test if the current cpu is offline and call printk_tick() directly which clears the condition. Alternatively I tried a cpu hotplug notifier which would clear the condition, however between calling the notifier function and printk_needs_cpu() something could have called printk() again and the problem is back again. This seems to be the safest fix. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org LKML-Reference: <20101126120235.406766476@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | * printk: Fix wake_up_klogd() vs cpu hotplugHeiko Carstens2010-11-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | wake_up_klogd() may get called from preemptible context but uses __raw_get_cpu_var() to write to a per cpu variable. If it gets preempted between getting the address and writing to it, the cpu in question could be offline if the process gets scheduled back and hence writes to the per cpu data of an offline cpu. This buggy behaviour was introduced with fa33507a "printk: robustify printk, fix #2" which was supposed to fix a "using smp_processor_id() in preemptible" warning. Let's use this_cpu_write() instead which disables preemption and makes sure that the outlined scenario cannot happen. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101126124247.GC7023@osiris.boeblingen.de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | Merge branch 'irq-fixes-for-linus' of ↵Linus Torvalds2010-12-07
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: Fix incorrect proc spurious output
| | * | | | genirq: Fix incorrect proc spurious outputKenji Kaneshige2010-12-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit a1afb637(switch /proc/irq/*/spurious to seq_file) all /proc/irq/XX/spurious files show the information of irq 0. Current irq_spurious_proc_open() passes on NULL as the 3rd argument, which is used as an IRQ number in irq_spurious_proc_show(), to the single_open(). Because of this, all the /proc/irq/XX/spurious file shows IRQ 0 information regardless of the IRQ number. To fix the problem, irq_spurious_proc_open() must pass on the appropreate data (IRQ number) to single_open(). Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Reviewed-by: Yong Zhang <yong.zhang0@gmail.com> LKML-Reference: <4CF4B778.90604@jp.fujitsu.com> Cc: stable@kernel.org [2.6.33+] Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | Merge branch 'pm-fixes' of ↵Linus Torvalds2010-12-06
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6 * 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6: PM / Hibernate: Fix memory corruption related to swap PM / Hibernate: Use async I/O when reading compressed hibernation image
| | * | | | | PM / Hibernate: Fix memory corruption related to swapRafael J. Wysocki2010-12-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a problem that swap pages allocated before the creation of a hibernation image can be released and used for storing the contents of different memory pages while the image is being saved. Since the kernel stored in the image doesn't know of that, it causes memory corruption to occur after resume from hibernation, especially on systems with relatively small RAM that need to swap often. This issue can be addressed by keeping the GFP_IOFS bits clear in gfp_allowed_mask during the entire hibernation, including the saving of the image, until the system is finally turned off or the hibernation is aborted. Unfortunately, for this purpose it's necessary to rework the way in which the hibernate and suspend code manipulates gfp_allowed_mask. This change is based on an earlier patch from Hugh Dickins. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reported-by: Ondrej Zary <linux@rainbow-software.org> Acked-by: Hugh Dickins <hughd@google.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: stable@kernel.org
| | * | | | | PM / Hibernate: Use async I/O when reading compressed hibernation imageBojan Smojver2010-12-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a fix for reading LZO compressed image using async I/O. Essentially, instead of having just one page into which we keep reading blocks from swap, we allocate enough of them to cover the largest compressed size and then let block I/O pick them all up. Once we have them all (and here we wait), we decompress them, as usual. Obviously, the very first block we still pick up synchronously, because we need to know the size of the lot before we pick up the rest. Also fixed the copyright line, which I've forgotten before. Signed-off-by: Bojan Smojver <bojan@rexursive.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
| * | | | | | do_exit(): make sure that we run with get_fs() == USER_DSNelson Elhage2010-12-02
| | |/ / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a user manages to trigger an oops with fs set to KERNEL_DS, fs is not otherwise reset before do_exit(). do_exit may later (via mm_release in fork.c) do a put_user to a user-controlled address, potentially allowing a user to leverage an oops into a controlled write into kernel memory. This is only triggerable in the presence of another bug, but this potentially turns a lot of DoS bugs into privilege escalations, so it's worth fixing. I have proof-of-concept code which uses this bug along with CVE-2010-3849 to write a zero to an arbitrary kernel address, so I've tested that this is not theoretical. A more logical place to put this fix might be when we know an oops has occurred, before we call do_exit(), but that would involve changing every architecture, in multiple places. Let's just stick it in do_exit instead. [akpm@linux-foundation.org: update code comment] Signed-off-by: Nelson Elhage <nelhage@ksplice.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds2010-11-28
| |\ \ \ \ \ | | |_|/ / / | |/| | / / | | | |/ / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf: Fix the software context switch counter perf, x86: Fixup Kconfig deps x86, perf, nmi: Disable perf if counters are not accessible perf: Fix inherit vs. context rotation bug
| | * | | perf: Fix the software context switch counterPeter Zijlstra2010-11-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Stephane noticed that because the perf_sw_event() call is inside the perf_event_task_sched_out() call it won't get called unless we have a per-task counter. Reported-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | perf: Fix inherit vs. context rotation bugThomas Gleixner2010-11-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It was found that sometimes children of tasks with inherited events had one extra event. Eventually it turned out to be due to the list rotation no being exclusive with the list iteration in the inheritance code. Cure this by temporarily disabling the rotation while we inherit the events. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds2010-11-26
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: posix-cpu-timers: Rcu_read_lock/unlock protect find_task_by_vpid call
| | * | | | posix-cpu-timers: Rcu_read_lock/unlock protect find_task_by_vpid callSergey Senozhatsky2010-11-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 4221a9918e38b7494cee341dda7b7b4bb8c04bde "Add RCU check for find_task_by_vpid()" introduced rcu_lockdep_assert to find_task_by_pid_ns. Add rcu_read_lock/rcu_read_unlock to call find_task_by_vpid. Tetsuo Handa wrote: | Quoting from one of posts in that thead | http://kerneltrap.org/mailarchive/linux-kernel/2010/2/8/4536388 | || Usually tasklist gives enough protection, but if copy_process() fails || it calls free_pid() lockless and does call_rcu(delayed_put_pid(). || This means, without rcu lock find_pid_ns() can't scan the hash table || safely. Thomas Gleixner wrote: | We can remove the tasklist_lock while at it. rcu_read_lock is enough. Patch also replaces thread_group_leader with has_group_leader_pid in accordance to comment by Oleg Nesterov: | ... thread_group_leader() check is not relaible without | tasklist. If we race with de_thread() find_task_by_vpid() can find | the new leader before it updates its ->group_leader. | | perhaps it makes sense to change posix_cpu_timer_create() to use | has_group_leader_pid() instead, just to make this code not look racy | and avoid adding new problems. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> LKML-Reference: <20101103165256.GD30053@swordfish.minsk.epam.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds2010-11-26
| |\ \ \ \ \ | | | |/ / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf symbols: Remove incorrect open-coded container_of() perf record: Handle restrictive permissions in /proc/{kallsyms,modules} x86/kprobes: Prevent kprobes to probe on save_args() irq_work: Drop cmpxchg() result perf: Fix owner-list vs exit x86, hw_nmi: Move backtrace_mask declaration under ARCH_HAS_NMI_WATCHDOG tracing: Fix recursive user stack trace perf,hw_breakpoint: Initialize hardware api earlier x86: Ignore trap bits on single step exceptions tracing: Force arch_local_irq_* notrace for paravirt tracing: Fix module use of trace_bprintk()
| | * | | | irq_work: Drop cmpxchg() resultSergio Aguirre2010-11-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The compiler warned us about: kernel/irq_work.c: In function 'irq_work_run': kernel/irq_work.c:148: warning: value computed is not used Dropping the cmpxchg() result is indeed weird, but correct - so annotate away the warning. Signed-off-by: Sergio Aguirre <saaguirre@ti.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289930567-17828-1-git-send-email-saaguirre@ti.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | perf: Fix owner-list vs exitPeter Zijlstra2010-11-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Oleg noticed that a perf-fd keeping a reference on the creating task leads to a few funny side effects. There's two different aspects to this: - kernel based perf-events, these should not take out a reference on the creating task and appear on the task's event list since they're not bound to fds nor visible to userspace. - fork() and pthread_create(), these can lead to the creating task dying (and thus the task's event-list becomming useless) but keeping the list and ref alive until the event is closed. Combined they lead to malfunction of the ptrace hw_tracepoints. Cure this by not considering kernel based perf_events for the owner-list and destroying the owner-list when the owner dies. Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Oleg Nesterov <oleg@redhat.com> LKML-Reference: <1289576883.2084.286.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | Merge branch 'perf/urgent' of ↵Ingo Molnar2010-11-18
| | |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/urgent
| | | * | | | perf,hw_breakpoint: Initialize hardware api earlierJason Wessel2010-11-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When using early debugging, the kernel does not initialize the hw_breakpoint API early enough and causes the late initialization of the kernel debugger to fail. The boot arguments are: earlyprintk=vga ekgdboc=kbd kgdbwait Then simply type "go" at the kdb prompt and boot. The kernel will later emit the message: kgdb: Could not allocate hwbreakpoints And at that point the kernel debugger will cease to work correctly. The solution is to initialize the hw_breakpoint at the same time that all the other perf call backs are initialized instead of using a core_initcall() initialization which happens well after the kernel debugger can make use of hardware breakpoints. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Ingo Molnar <mingo@elte.hu> CC: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4CD3396D.1090308@windriver.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
| | * | | | | Merge branch 'tip/perf/urgent-3' of ↵Ingo Molnar2010-11-18
| | |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
| | | * | | | | tracing: Fix recursive user stack traceSteven Rostedt2010-11-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The user stack trace can fault when examining the trace. Which would call the do_page_fault handler, which would trace again, which would do the user stack trace, which would fault and call do_page_fault again ... Thus this is causing a recursive bug. We need to have a recursion detector here. [ Resubmitted by Jiri Olsa ] [ Eric Dumazet recommended using __this_cpu_* instead of __get_cpu_* ] Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <1289390172-9730-3-git-send-email-jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| | | * | | | | tracing: Fix module use of trace_bprintk()Steven Rostedt2010-11-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On use of trace_printk() there's a macro that determines if the format is static or a variable. If it is static, it defaults to __trace_bprintk() otherwise it uses __trace_printk(). A while ago, Lai Jiangshan added __trace_bprintk(). In that patch, we discussed a way to allow modules to use it. The difference between __trace_bprintk() and __trace_printk() is that for faster processing, just the format and args are stored in the trace instead of running it through a sprintf function. In order to do this, the format used by the __trace_bprintk() had to be persistent. See commit 1ba28e02a18cbdbea123836f6c98efb09cbf59ec The problem comes with trace_bprintk() where the module is unloaded. The pointer left in the buffer is still pointing to the format. To solve this issue, the formats in the module were copied into kernel core. If the same format was used, they would use the same copy (to prevent memory leak). This all worked well until we tried to merge everything. At the time this was written, Lai Jiangshan, Frederic Weisbecker, Ingo Molnar and myself were all touching the same code. When this was merged, we lost the part of it that was in module.c. This kept out the copying of the formats and unloading the module could cause bad pointers left in the ring buffer. This patch adds back (with updates required for current kernel) the module code that sets up the necessary pointers. Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | | | | | Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds2010-11-26
| |\ \ \ \ \ \ \ | | |_|_|_|_|/ / | |/| | | | | / | | | |_|_|_|/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Fix idle balancing sched: Fix volanomark performance regression
| | * | | | | sched: Fix idle balancingNikhil Rao2010-11-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | An earlier commit reverts idle balancing throttling reset to fix a 30% regression in volanomark throughput. We still need to reset idle_stamp when we pull a task in newidle balance. Reported-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1290022924-3548-1-git-send-email-ncrao@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | sched: Fix volanomark performance regressionAlex Shi2010-11-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit fab4762 triggers excessive idle balancing, causing a ~30% loss in volanomark throughput. Remove idle balancing throttle reset. Originally-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289928732.5169.211.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | | sched: Add 'autogroup' scheduling feature: automated per session task groupsMike Galbraith2010-11-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A recurring complaint from CFS users is that parallel kbuild has a negative impact on desktop interactivity. This patch implements an idea from Linus, to automatically create task groups. Currently, only per session autogroups are implemented, but the patch leaves the way open for enhancement. Implementation: each task's signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls setsid(), a new task group is created, the process is moved into the new task group, and a reference to the preveious task group is dropped. Child processes inherit this task group thereafter, and increase it's refcount. When the last thread of a process exits, the process's reference is dropped, such that when the last process referencing an autogroup exits, the autogroup is destroyed. At runqueue selection time, IFF a task has no cgroup assignment, its current autogroup is used. Autogroup bandwidth is controllable via setting it's nice level through the proc filesystem: cat /proc/<pid>/autogroup Displays the task's group and the group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task group's shares to the weight of nice <level> task. Setting nice level is rate limited for !admin users due to the abuse risk of task group locking. The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via the boot option noautogroup, and can also be turned on/off on the fly via: echo [01] > /proc/sys/kernel/sched_autogroup_enabled ... which will automatically move tasks to/from the root task group. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul Turner <pjt@google.com> Cc: Oleg Nesterov <oleg@redhat.com> [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | | sched: Fix unregister_fair_sched_group()Paul Turner2010-11-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the flipping and flopping between calling unregister_fair_sched_group() on a per-cpu versus per-group basis we ended up in a bad state. Remove from the list for the passed cpu as opposed to some arbitrary index. ( This fixes explosions w/ autogroup as well as a group creation/destruction stress test. ) Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20101130005740.080828123@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | | sched: Remove unused argument dest_cpu to migrate_task()Nikanth Karthikesan2010-11-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove unused argument, 'dest_cpu' of migrate_task(), and pass runqueue, as it is always known at the call site. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <201011261237.09187.knikanth@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | | mutexes, sched: Introduce arch_mutex_cpu_relax()Gerald Schaefer2010-11-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The spinning mutex implementation uses cpu_relax() in busy loops as a compiler barrier. Depending on the architecture, cpu_relax() may do more than needed in this specific mutex spin loops. On System z we also give up the time slice of the virtual cpu in cpu_relax(), which prevents effective spinning on the mutex. This patch replaces cpu_relax() in the spinning mutex code with arch_mutex_cpu_relax(), which can be defined by each architecture that selects HAVE_ARCH_MUTEX_CPU_RELAX. The default is still cpu_relax(), so this patch should not affect other architectures than System z for now. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1290437256.7455.4.camel@thinkpad> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | | Merge commit 'v2.6.37-rc3' into sched/coreIngo Molnar2010-11-26
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge reason: Pick up latest fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | Revert "kernel: make /proc/kallsyms mode 400 to reduce ease of attacking"Linus Torvalds2010-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 59365d136d205cc20fe666ca7f89b1c5001b0d5a. It turns out that this can break certain existing user land setups. Quoth Sarah Sharp: "On Wednesday, I updated my branch to commit 460781b from linus' tree, and my box would not boot. klogd segfaulted, which stalled the whole system. At first I thought it actually hung the box, but it continued booting after 5 minutes, and I was able to log in. It dropped back to the text console instead of the graphical bootup display for that period of time. dmesg surprisingly still works. I've bisected the problem down to this commit (commit 59365d136d205cc20fe666ca7f89b1c5001b0d5a) The box is running klogd 1.5.5ubuntu3 (from Jaunty). Yes, I know that's old. I read the bit in the commit about changing the permissions of kallsyms after boot, but if I can't boot that doesn't help." So let's just keep the old default, and encourage distributions to do the "chmod -r /proc/kallsyms" in their bootup scripts. This is not worth a kernel option to change default behavior, since it's so easily done in user space. Reported-and-bisected-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: Marcus Meissner <meissner@suse.de> Cc: Tejun Heo <tj@kernel.org> Cc: Eugene Teo <eugeneteo@kernel.org> Cc: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | Merge branch 'for_linus' of ↵Linus Torvalds2010-11-18
| |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: kgdb,ppc: Fix regression in evr register handling kgdb,x86: fix regression in detach handling kdb: fix crash when KDB_BASE_CMD_MAX is exceeded kdb: fix memory leak in kdb_main.c
| | * | | | | | kdb: fix crash when KDB_BASE_CMD_MAX is exceededJovi Zhang2010-11-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the number of dyanmic kdb commands exceeds KDB_BASE_CMD_MAX, the kernel will fault. Signed-off-by: Jovi Zhang <bookjovi@gmail.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
| | * | | | | | kdb: fix memory leak in kdb_main.cJovi Zhang2010-11-17
| | | |/ / / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Call kfree in the error path as well as the success path in kdb_ll(). Signed-off-by: Jovi Zhang <bookjovi@gmail.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
| * | | | | | BKL: remove extraneous #include <smp_lock.h>Arnd Bergmann2010-11-17
| | |/ / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The big kernel lock has been removed from all these files at some point, leaving only the #include. Remove this too as a cleanup. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | kernel: make /proc/kallsyms mode 400 to reduce ease of attackingMarcus Meissner2010-11-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Making /proc/kallsyms readable only for root by default makes it slightly harder for attackers to write generic kernel exploits by removing one source of knowledge where things are in the kernel. This is the second submit, discussion happened on this on first submit and mostly concerned that this is just one hole of the sieve ... but one of the bigger ones. Changing the permissions of at least System.map and vmlinux is also required to fix the same set, but a packaging issue. Target of this starter patch and follow ups is removing any kind of kernel space address information leak from the kernel. [ Side note: the default of root-only reading is the "safe" value, and it's easy enough to then override at any time after boot. The /proc filesystem allows root to change the permissions with a regular chmod, so you can "revert" this at run-time by simply doing chmod og+r /proc/kallsyms as root if you really want regular users to see the kernel symbols. It does help some tools like "perf" figure them out without any setup, so it may well make sense in some situations. - Linus ] Signed-off-by: Marcus Meissner <meissner@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Eugene Teo <eugeneteo@kernel.org> Reviewed-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds2010-11-16
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Fix cross-sched-class wakeup preemption sched: Fix runnable condition for stoptask sched: Use group weight, idle cpu metrics to fix imbalances during idle
| | * | | | | sched: Fix cross-sched-class wakeup preemptionPeter Zijlstra2010-11-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of dealing with sched classes inside each check_preempt_curr() implementation, pull out this logic into the generic wakeup preemption path. This fixes a hang in KVM (and others) where we are waiting for the stop machine thread to run ... Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Tested-by: Marcelo Tosatti <mtosatti@redhat.com> Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1288891946.2039.31.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | sched: Fix runnable condition for stoptaskPeter Zijlstra2010-11-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Heiko reported that the TASK_RUNNING check is not sufficient for CONFIG_PREEMPT=y since we can get preempted with !TASK_RUNNING. He suggested adding a ->se.on_rq test to the existing TASK_RUNNING one, however TASK_RUNNING will always have ->se.on_rq, so we might as well reduce that to a single test. [ stop tasks should never get preempted, but its good to handle this case correctly should this ever happen ] Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | sched: Use group weight, idle cpu metrics to fix imbalances during idleSuresh Siddha2010-11-10
| | | |_|_|/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we consider a sched domain to be well balanced when the imbalance is less than the domain's imablance_pct. As the number of cores and threads are increasing, current values of imbalance_pct (for example 25% for a NUMA domain) are not enough to detect imbalances like: a) On a WSM-EP system (two sockets, each having 6 cores and 12 logical threads), 24 cpu-hogging tasks get scheduled as 13 on one socket and 11 on another socket. Leading to an idle HT cpu. b) On a hypothetial 2 socket NHM-EX system (each socket having 8 cores and 16 logical threads), 16 cpu-hogging tasks can get scheduled as 9 on one socket and 7 on another socket. Leaving one core in a socket idle whereas in another socket we have a core having both its HT siblings busy. While this issue can be fixed by decreasing the domain's imbalance_pct (by making it a function of number of logical cpus in the domain), it can potentially cause more task migrations across sched groups in an overloaded case. Fix this by using imbalance_pct only during newly_idle and busy load balancing. And during idle load balancing, check if there is an imbalance in number of idle cpu's across the busiest and this sched_group or if the busiest group has more tasks than its weight that the idle cpu in this_group can pull. Reported-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1284760952.2676.11.camel@sbsiddha-MOBL3.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | Merge branch 'pm-fixes' of ↵Linus Torvalds2010-11-16
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6 * 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6: PM / PM QoS: Fix reversed min and max PM / OPP: Hide OPP configuration when SoCs do not provide an implementation PM: Allow devices to be removed during late suspend and early resume
| | * | | | | PM / PM QoS: Fix reversed min and maxColin Cross2010-11-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pm_qos_get_value had min and max reversed, causing all pm_qos requests to have no effect. Signed-off-by: Colin Cross <ccross@android.com> Acked-by: mark <markgross@thegnar.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: stable@kernel.org
| | * | | | | PM / OPP: Hide OPP configuration when SoCs do not provide an implementationMark Brown2010-11-10
| | |/ / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the OPP API is only useful with an appropraite SoC-specific implementation there is no point in offering the ability to enable the API on general systems. Provide an ARCH_HAS OPP Kconfig symbol which masks out the option unless selected by an implementation. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Nishanth Menon <nm@ti.com> Acked-by: Kevin Hilman <khilman@deeprootsystems.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
| * | | | | Merge branch 'futexes-for-linus' of ↵Linus Torvalds2010-11-16
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: futex: Address compiler warnings in exit_robust_list
| | * | | | | futex: Address compiler warnings in exit_robust_listDarren Hart2010-11-10
| | |/ / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 1dcc41bb (futex: Change 3rd arg of fetch_robust_entry() to unsigned int*) some gcc versions decided to emit the following warning: kernel/futex.c: In function ‘exit_robust_list’: kernel/futex.c:2492: warning: ‘next_pi’ may be used uninitialized in this function The commit did not introduce the warning as gcc should have warned before that commit as well. It's just gcc being silly. The code path really can't result in next_pi being unitialized (or should not), but let's keep the build clean. Annotate next_pi as an uninitialized_var. [ tglx: Addressed the same issue in futex_compat.c and massaged the changelog ] Signed-off-by: Darren Hart <dvhart@linux.intel.com> Tested-by: Matt Fleming <matt@console-pimps.org> Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: John Kacur <jkacur@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1288897200-13008-1-git-send-email-dvhart@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6Linus Torvalds2010-11-16
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6: [S390] kprobes: Fix the return address of multiple kretprobes [S390] kprobes: disable interrupts throughout [S390] ftrace: build without frame pointers on s390 [S390] mm: add devmem_is_allowed() for STRICT_DEVMEM checking [S390] vmlogrdr: purge after recording is switched off [S390] cio: fix incorrect ccw_device_init_count [S390] tape: add medium state notifications [S390] fix get_user_pages_fast
| | * | | | | [S390] ftrace: build without frame pointers on s390Heiko Carstens2010-11-10
| | |/ / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | s390 doesn't need FRAME_POINTERS in order to have a working function tracer. We don't need frame pointers in order to get strack traces since we always have valid backchains by using the -mkernel-backchain gcc option. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>