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* Merge branch 'tip/perf/urgent-2' of ↵Ingo Molnar2013-03-18
|\ | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent Pull tracing fixes from Steven Rostedt. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * tracing: Prevent buffer overwrite disabled for latency tracersSteven Rostedt (Red Hat)2013-03-14
| | | | | | | | | | | | | | | | | | | | | | | | | | The latency tracers require the buffers to be in overwrite mode, otherwise they get screwed up. Force the buffers to stay in overwrite mode when latency tracers are enabled. Added a flag_changed() method to the tracer structure to allow the tracers to see what flags are being changed, and also be able to prevent the change from happing. Cc: stable@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Keep overwrite in sync between regular and snapshot buffersSteven Rostedt (Red Hat)2013-03-14
| | | | | | | | | | | | | | | | | | | | | | | | | | Changing the overwrite mode for the ring buffer via the trace option only sets the normal buffer. But the snapshot buffer could swap with it, and then the snapshot would be in non overwrite mode and the normal buffer would be in overwrite mode, even though the option flag states otherwise. Keep the two buffers overwrite modes in sync. Cc: stable@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Protect tracer flags with trace_types_lockSteven Rostedt (Red Hat)2013-03-14
| | | | | | | | | | | | | | | | | | | | | | | | | | Seems that the tracer flags have never been protected from synchronous writes. Luckily, admins don't usually modify the tracing flags via two different tasks. But if scripts were to be used to modify them, then they could get corrupted. Move the trace_types_lock that protects against tracers changing to also protect the flags being set. Cc: stable@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | Merge branch 'tip/perf/urgent-2' of ↵Ingo Molnar2013-03-14
|\| | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent Pull tracing fixes from Steven Rostedt. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * tracing: Fix free of probe entry by calling call_rcu_sched()Steven Rostedt (Red Hat)2013-03-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because function tracing is very invasive, and can even trace calls to rcu_read_lock(), RCU access in function tracing is done with preempt_disable_notrace(). This requires a synchronize_sched() for updates and not a synchronize_rcu(). Function probes (traceon, traceoff, etc) must be freed after a synchronize_sched() after its entry has been removed from the hash. But call_rcu() is used. Fix this by using call_rcu_sched(). Also fix the usage to use hlist_del_rcu() instead of hlist_del(). Cc: stable@vger.kernel.org Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Fix race in snapshot swappingSteven Rostedt (Red Hat)2013-03-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Although the swap is wrapped with a spin_lock, the assignment of the temp buffer used to swap is not within that lock. It needs to be moved into that lock, otherwise two swaps happening on two different CPUs, can end up using the wrong temp buffer to assign in the swap. Luckily, all current callers of the swap function appear to have their own locks. But in case something is added that allows two different callers to call the swap, then there's a chance that this race can trigger and corrupt the buffers. New code is coming soon that will allow for this race to trigger. I've Cc'd stable, so this bug will not show up if someone backports one of the changes that can trigger this bug. Cc: stable@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2013-03-11
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Misc minor fixes mostly related to tracing" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: s390: Fix a header dependencies related build error tracing: update documentation of snapshot utility tracing: Do not return EINVAL in snapshot when not allocated tracing: Add help of snapshot feature when snapshot is empty ftrace: Update the kconfig for DYNAMIC_FTRACE
| * tracing: Do not return EINVAL in snapshot when not allocatedSteven Rostedt (Red Hat)2013-03-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To use the tracing snapshot feature, writing a '1' into the snapshot file causes the snapshot buffer to be allocated if it has not already been allocated and dose a 'swap' with the main buffer, so that the snapshot now contains what was in the main buffer, and the main buffer now writes to what was the snapshot buffer. To free the snapshot buffer, a '0' is written into the snapshot file. To clear the snapshot buffer, any number but a '0' or '1' is written into the snapshot file. But if the file is not allocated it returns -EINVAL error code. This is rather pointless. It is better just to do nothing and return success. Acked-by: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Add help of snapshot feature when snapshot is emptySteven Rostedt (Red Hat)2013-03-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When cat'ing the snapshot file, instead of showing an empty trace header like the trace file does, show how to use the snapshot feature. Also, this is a good place to show if the snapshot has been allocated or not. Users may want to "pre allocate" the snapshot to have a fast "swap" of the current buffer. Otherwise, a swap would be slow and might fail as it would need to allocate the snapshot buffer, and that might fail under tight memory constraints. Here's what it looked like before: # tracer: nop # # entries-in-buffer/entries-written: 0/0 #P:4 # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | Here's what it looks like now: # tracer: nop # # # * Snapshot is freed * # # Snapshot commands: # echo 0 > snapshot : Clears and frees snapshot buffer # echo 1 > snapshot : Allocates snapshot buffer, if not already allocated. # Takes a snapshot of the main buffer. # echo 2 > snapshot : Clears snapshot buffer (but does not allocate) # (Doesn't have to be '2' works with any number that # is not a '0' or '1') Acked-by: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Update the kconfig for DYNAMIC_FTRACESteven Rostedt2013-02-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The prompt to enable DYNAMIC_FTRACE (the ability to nop and enable function tracing at run time) had a confusing statement: "enable/disable ftrace tracepoints dynamically" This was written before tracepoints were added to the kernel, but now that tracepoints have been added, this is very confusing and has confused people enough to give wrong information during presentations. Not only that, I looked at the help text, and it still references that dreaded daemon that use to wake up once a second to update the nop locations and brick NICs, that hasn't been around for over five years. Time to bring the text up to the current decade. Cc: stable@vger.kernel.org Reported-by: Ezequiel Garcia <elezegarcia@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | Merge tag 'metag-v3.9-rc1-v4' of ↵Linus Torvalds2013-03-03
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag Pull new ImgTec Meta architecture from James Hogan: "This adds core architecture support for Imagination's Meta processor cores, followed by some later miscellaneous arch/metag cleanups and fixes which I kept separate to ease review: - Support for basic Meta 1 (ATP) and Meta 2 (HTP) core architecture - A few fixes all over, particularly for symbol prefixes - A few privilege protection fixes - Several cleanups (setup.c includes, split out a lot of metag_ksyms.c) - Fix some missing exports - Convert hugetlb to use vm_unmapped_area() - Copy device tree to non-init memory - Provide dma_get_sgtable()" * tag 'metag-v3.9-rc1-v4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag: (61 commits) metag: Provide dma_get_sgtable() metag: prom.h: remove declaration of metag_dt_memblock_reserve() metag: copy devicetree to non-init memory metag: cleanup metag_ksyms.c includes metag: move mm/init.c exports out of metag_ksyms.c metag: move usercopy.c exports out of metag_ksyms.c metag: move setup.c exports out of metag_ksyms.c metag: move kick.c exports out of metag_ksyms.c metag: move traps.c exports out of metag_ksyms.c metag: move irq enable out of irqflags.h on SMP genksyms: fix metag symbol prefix on crc symbols metag: hugetlb: convert to vm_unmapped_area() metag: export clear_page and copy_page metag: export metag_code_cache_flush_all metag: protect more non-MMU memory regions metag: make TXPRIVEXT bits explicit metag: kernel/setup.c: sort includes perf: Enable building perf tools for Meta metag: add boot time LNKGET/LNKSET check metag: add __init to metag_cache_probe() ...
| * | trace/ring_buffer: handle 64bit aligned structsJames Hogan2013-03-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some 32 bit architectures require 64 bit values to be aligned (for example Meta which has 64 bit read/write instructions). These require 8 byte alignment of event data too, so use !CONFIG_HAVE_64BIT_ALIGNED_ACCESS instead of !CONFIG_64BIT || CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to decide alignment, and align buffer_data_page::data accordingly. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> (previous version subtly different)
* | | Merge branch 'for-3.9/core' of git://git.kernel.dk/linux-blockLinus Torvalds2013-02-28
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block IO core bits from Jens Axboe: "Below are the core block IO bits for 3.9. It was delayed a few days since my workstation kept crashing every 2-8h after pulling it into current -git, but turns out it is a bug in the new pstate code (divide by zero, will report separately). In any case, it contains: - The big cfq/blkcg update from Tejun and and Vivek. - Additional block and writeback tracepoints from Tejun. - Improvement of the should sort (based on queues) logic in the plug flushing. - _io() variants of the wait_for_completion() interface, using io_schedule() instead of schedule() to contribute to io wait properly. - Various little fixes. You'll get two trivial merge conflicts, which should be easy enough to fix up" Fix up the trivial conflicts due to hlist traversal cleanups (commit b67bfe0d42ca: "hlist: drop the node parameter from iterators"). * 'for-3.9/core' of git://git.kernel.dk/linux-block: (39 commits) block: remove redundant check to bd_openers() block: use i_size_write() in bd_set_size() cfq: fix lock imbalance with failed allocations drivers/block/swim3.c: fix null pointer dereference block: don't select PERCPU_RWSEM block: account iowait time when waiting for completion of IO request sched: add wait_for_completion_io[_timeout] writeback: add more tracepoints block: add block_{touch|dirty}_buffer tracepoint buffer: make touch_buffer() an exported function block: add @req to bio_{front|back}_merge tracepoints block: add missing block_bio_complete() tracepoint block: Remove should_sort judgement when flush blk_plug block,elevator: use new hashtable implementation cfq-iosched: add hierarchical cfq_group statistics cfq-iosched: collect stats from dead cfqgs cfq-iosched: separate out cfqg_stats_reset() from cfq_pd_reset_stats() blkcg: make blkcg_print_blkgs() grab q locks instead of blkcg lock block: RCU free request_queue blkcg: implement blkg_[rw]stat_recursive_sum() and blkg_[rw]stat_merge() ...
| * | | block: add @req to bio_{front|back}_merge tracepointsTejun Heo2013-01-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bio_{front|back}_merge tracepoints report a bio merging into an existing request but didn't specify which request the bio is being merged into. Add @req to it. This makes it impossible to share the event template with block_bio_queue - split it out. @req isn't used or exported to userland at this point and there is no userland visible behavior change. Later changes will make use of the extra parameter. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * | | block: add missing block_bio_complete() tracepointTejun Heo2013-01-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bio completion didn't kick block_bio_complete TP. Only dm was explicitly triggering the TP on IO completion. This makes block_bio_complete TP useless for tracers which want to know about bios, and all other bio based drivers skip generating blktrace completion events. This patch makes all bio completions via bio_endio() generate block_bio_complete TP. * Explicit trace_block_bio_complete() invocation removed from dm and the trace point is unexported. * @rq dropped from trace_block_bio_complete(). bios may fly around w/o queue associated. Verifying and accessing the assocaited queue belongs to TP probes. * blktrace now gets both request and bio completions. Make it ignore bio completions if request completion path is happening. This makes all bio based drivers generate blktrace completion events properly and makes the block_bio_complete TP actually useful. v2: With this change, block_bio_complete TP could be invoked on sg commands which have bio's with %NULL bi_bdev. Update TP assignment code to check whether bio->bi_bdev is %NULL before dereferencing. Signed-off-by: Tejun Heo <tj@kernel.org> Original-patch-by: Namhyung Kim <namhyung@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Alasdair Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Cc: Neil Brown <neilb@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | | | hlist: drop the node parameter from iteratorsSasha Levin2013-02-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2013-02-26
|\ \ \ \ | | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar. * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86: Add Intel IvyBridge event scheduling constraints ftrace: Call ftrace cleanup module notifier after all other notifiers tracing/syscalls: Allow archs to ignore tracing compat syscalls
| * | | Merge branch 'tip/perf/core' of ↵Ingo Molnar2013-02-20
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent Pull two fixes from Steven Rostedt. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | ftrace: Call ftrace cleanup module notifier after all other notifiersSteven Rostedt (Red Hat)2013-02-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit: c1bf08ac "ftrace: Be first to run code modification on modules" changed ftrace module notifier's priority to INT_MAX in order to process the ftrace nops before anything else could touch them (namely kprobes). This was the correct thing to do. Unfortunately, the ftrace module notifier also contains the ftrace clean up code. As opposed to the set up code, this code should be run *after* all the module notifiers have run in case a module is doing correct clean-up and unregisters its ftrace hooks. Basically, ftrace needs to do clean up on module removal, as it needs to know about code being removed so that it doesn't try to modify that code. But after it removes the module from its records, if a ftrace user tries to remove a probe, that removal will fail due as the record of that code segment no longer exists. Nothing really bad happens if the probe removal is called after ftrace did the clean up, but the ftrace removal function will return an error. Correct code (such as kprobes) will produce a WARN_ON() if it fails to remove the probe. As people get annoyed by frivolous warnings, it's best to do the ftrace clean up after everything else. By splitting the ftrace_module_notifier into two notifiers, one that does the module load setup that is run at high priority, and the other that is called for module clean up that is run at low priority, the problem is solved. Cc: stable@vger.kernel.org Reported-by: Frank Ch. Eigler <fche@redhat.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| | * | | tracing/syscalls: Allow archs to ignore tracing compat syscallsSteven Rostedt2013-02-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tracing of ia32 compat system calls has been a bit of a pain as they use different system call numbers than the 64bit equivalents. I wrote a simple 'lls' program that lists files. I compiled it as a i686 ELF binary and ran it under a x86_64 box. This is the result: echo 0 > /debug/tracing/tracing_on echo 1 > /debug/tracing/events/syscalls/enable echo 1 > /debug/tracing/tracing_on ; ./lls ; echo 0 > /debug/tracing/tracing_on grep lls /debug/tracing/trace [.. skipping calls before TS_COMPAT is set ...] lls-1127 [005] d... 936.409188: sys_recvfrom(fd: 0, ubuf: 4d560fc4, size: 0, flags: 8048034, addr: 8, addr_len: f7700420) lls-1127 [005] d... 936.409190: sys_recvfrom -> 0x8a77000 lls-1127 [005] d... 936.409211: sys_lgetxattr(pathname: 0, name: 1000, value: 3, size: 22) lls-1127 [005] d... 936.409215: sys_lgetxattr -> 0xf76ff000 lls-1127 [005] d... 936.409223: sys_dup2(oldfd: 4d55ae9b, newfd: 4) lls-1127 [005] d... 936.409228: sys_dup2 -> 0xfffffffffffffffe lls-1127 [005] d... 936.409236: sys_newfstat(fd: 4d55b085, statbuf: 80000) lls-1127 [005] d... 936.409242: sys_newfstat -> 0x3 lls-1127 [005] d... 936.409243: sys_removexattr(pathname: 3, name: ffcd0060) lls-1127 [005] d... 936.409244: sys_removexattr -> 0x0 lls-1127 [005] d... 936.409245: sys_lgetxattr(pathname: 0, name: 19614, value: 1, size: 2) lls-1127 [005] d... 936.409248: sys_lgetxattr -> 0xf76e5000 lls-1127 [005] d... 936.409248: sys_newlstat(filename: 3, statbuf: 19614) lls-1127 [005] d... 936.409249: sys_newlstat -> 0x0 lls-1127 [005] d... 936.409262: sys_newfstat(fd: f76fb588, statbuf: 80000) lls-1127 [005] d... 936.409279: sys_newfstat -> 0x3 lls-1127 [005] d... 936.409279: sys_close(fd: 3) lls-1127 [005] d... 936.421550: sys_close -> 0x200 lls-1127 [005] d... 936.421558: sys_removexattr(pathname: 3, name: ffcd00d0) lls-1127 [005] d... 936.421560: sys_removexattr -> 0x0 lls-1127 [005] d... 936.421569: sys_lgetxattr(pathname: 4d564000, name: 1b1abc, value: 5, size: 802) lls-1127 [005] d... 936.421574: sys_lgetxattr -> 0x4d564000 lls-1127 [005] d... 936.421575: sys_capget(header: 4d70f000, dataptr: 1000) lls-1127 [005] d... 936.421580: sys_capget -> 0x0 lls-1127 [005] d... 936.421580: sys_lgetxattr(pathname: 4d710000, name: 3000, value: 3, size: 812) lls-1127 [005] d... 936.421589: sys_lgetxattr -> 0x4d710000 lls-1127 [005] d... 936.426130: sys_lgetxattr(pathname: 4d713000, name: 2abc, value: 3, size: 32) lls-1127 [005] d... 936.426141: sys_lgetxattr -> 0x4d713000 lls-1127 [005] d... 936.426145: sys_newlstat(filename: 3, statbuf: f76ff3f0) lls-1127 [005] d... 936.426146: sys_newlstat -> 0x0 lls-1127 [005] d... 936.431748: sys_lgetxattr(pathname: 0, name: 1000, value: 3, size: 22) Obviously I'm not calling newfstat with a fd of 4d55b085. The calls are obviously incorrect, and confusing. Other efforts have been made to fix this: https://lkml.org/lkml/2012/3/26/367 But the real solution is to rewrite the syscall internals and come up with a fixed solution. One that doesn't require all the kluge that the current solution has. Thus for now, instead of outputting incorrect data, simply ignore them. With this patch the changes now have: #> grep lls /debug/tracing/trace #> Compat system calls simply are not traced. If users need compat syscalls, then they should just use the raw syscall tracepoints. For an architecture to make their compat syscalls ignored, it must define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS (done in asm/ftrace.h) and also define an arch_trace_is_compat_syscall() function that will return true if the current task should ignore tracing the syscall. I want to stress that this change does not affect actual syscalls in any way, shape or form. It is only used within the tracing system and doesn't interfere with the syscall logic at all. The changes are consolidated nicely into trace_syscalls.c and asm/ftrace.h. I had to make one small modification to asm/thread_info.h and that was to remove the include of asm/ftrace.h. As asm/ftrace.h required the current_thread_info() it was causing include hell. That include was added back in 2008 when the function graph tracer was added: commit caf4b323 "tracing, x86: add low level support for ftrace return tracing" It does not need to be included there. Link: http://lkml.kernel.org/r/1360703939.21867.99.camel@gandalf.local.home Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | | | Merge tag 'pm+acpi-3.9-rc1' of ↵Linus Torvalds2013-02-20
|\ \ \ \ \ | |/ / / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management updates from Rafael Wysocki: - Rework of the ACPI namespace scanning code from Rafael J. Wysocki with contributions from Bjorn Helgaas, Jiang Liu, Mika Westerberg, Toshi Kani, and Yinghai Lu. - ACPI power resources handling and ACPI device PM update from Rafael J Wysocki. - ACPICA update to version 20130117 from Bob Moore and Lv Zheng with contributions from Aaron Lu, Chao Guan, Jesper Juhl, and Tim Gardner. - Support for Intel Lynxpoint LPSS from Mika Westerberg. - cpuidle update from Len Brown including Intel Haswell support, C1 state for intel_idle, removal of global pm_idle. - cpuidle fixes and cleanups from Daniel Lezcano. - cpufreq fixes and cleanups from Viresh Kumar and Fabio Baltieri with contributions from Stratos Karafotis and Rickard Andersson. - Intel P-states driver for Sandy Bridge processors from Dirk Brandewie. - cpufreq driver for Marvell Kirkwood SoCs from Andrew Lunn. - cpufreq fixes related to ordering issues between acpi-cpufreq and powernow-k8 from Borislav Petkov and Matthew Garrett. - cpufreq support for Calxeda Highbank processors from Mark Langsdorf and Rob Herring. - cpufreq driver for the Freescale i.MX6Q SoC and cpufreq-cpu0 update from Shawn Guo. - cpufreq Exynos fixes and cleanups from Jonghwan Choi, Sachin Kamat, and Inderpal Singh. - Support for "lightweight suspend" from Zhang Rui. - Removal of the deprecated power trace API from Paul Gortmaker. - Assorted updates from Andreas Fleig, Colin Ian King, Davidlohr Bueso, Joseph Salisbury, Kees Cook, Li Fei, Nishanth Menon, ShuoX Liu, Srinivas Pandruvada, Tejun Heo, Thomas Renninger, and Yasuaki Ishimatsu. * tag 'pm+acpi-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (267 commits) PM idle: remove global declaration of pm_idle unicore32 idle: delete stray pm_idle comment openrisc idle: delete pm_idle mn10300 idle: delete pm_idle microblaze idle: delete pm_idle m32r idle: delete pm_idle, and other dead idle code ia64 idle: delete pm_idle cris idle: delete idle and pm_idle ARM64 idle: delete pm_idle ARM idle: delete pm_idle blackfin idle: delete pm_idle sparc idle: rename pm_idle to sparc_idle sh idle: rename global pm_idle to static sh_idle x86 idle: rename global pm_idle to static x86_idle APM idle: register apm_cpu_idle via cpuidle cpufreq / intel_pstate: Add kernel command line option disable intel_pstate. cpufreq / intel_pstate: Change to disallow module build tools/power turbostat: display SMI count by default intel_idle: export both C1 and C1E ACPI / hotplug: Fix concurrency issues and memory leaks ...
| * | | | PM / tracing: remove deprecated power trace APIPaul Gortmaker2013-01-25
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The text in Documentation said it would be removed in 2.6.41; the text in the Kconfig said removal in the 3.1 release. Either way you look at it, we are well past both, so push it off a cliff. Note that the POWER_CSTATE and the POWER_PSTATE are part of the legacy tracing API. Remove all tracepoints which use these flags. As can be seen from context, most already have a trace entry via trace_cpu_idle anyways. Also, the cpufreq/cpufreq.c PSTATE one is actually unpaired, as compared to the CSTATE ones which all have a clear start/stop. As part of this, the trace_power_frequency also becomes orphaned, so it too is deleted. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | | | Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2013-02-19
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler changes from Ingo Molnar: "Main changes: - scheduler side full-dynticks (user-space execution is undisturbed and receives no timer IRQs) preparation changes that convert the cputime accounting code to be full-dynticks ready, from Frederic Weisbecker. - Initial sched.h split-up changes, by Clark Williams - select_idle_sibling() performance improvement by Mike Galbraith: " 1 tbench pair (worst case) in a 10 core + SMT package: pre 15.22 MB/sec 1 procs post 252.01 MB/sec 1 procs " - sched_rr_get_interval() ABI fix/change. We think this detail is not used by apps (so it's not an ABI in practice), but lets keep it under observation. - misc RT scheduling cleanups, optimizations" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) sched/rt: Add <linux/sched/rt.h> header to <linux/init_task.h> cputime: Remove irqsave from seqlock readers sched, powerpc: Fix sched.h split-up build failure cputime: Restore CPU_ACCOUNTING config defaults for PPC64 sched/rt: Move rt specific bits into new header file sched/rt: Add a tuning knob to allow changing SCHED_RR timeslice sched: Move sched.h sysctl bits into separate header sched: Fix signedness bug in yield_to() sched: Fix select_idle_sibling() bouncing cow syndrome sched/rt: Further simplify pick_rt_task() sched/rt: Do not account zero delta_exec in update_curr_rt() cputime: Safely read cputime of full dynticks CPUs kvm: Prepare to add generic guest entry/exit callbacks cputime: Use accessors to read task cputime stats cputime: Allow dynamic switch between tick/virtual based cputime accounting cputime: Generic on-demand virtual cputime accounting cputime: Move default nsecs_to_cputime() to jiffies based cputime file cputime: Librarize per nsecs resolution cputime definitions cputime: Avoid multiplication overflow on utime scaling context_tracking: Export context state for generic vtime ... Fix up conflict in kernel/context_tracking.c due to comment additions.
| * | | | sched/rt: Move rt specific bits into new header fileClark Williams2013-02-07
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move rt scheduler definitions out of include/linux/sched.h into new file include/linux/sched/rt.h Signed-off-by: Clark Williams <williams@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20130207094707.7b9f825f@riff.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | Merge branch 'perf-core-for-linus' of ↵Linus Torvalds2013-02-19
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf changes from Ingo Molnar: "There are lots of improvements, the biggest changes are: Main kernel side changes: - Improve uprobes performance by adding 'pre-filtering' support, by Oleg Nesterov. - Make some POWER7 events available in sysfs, equivalent to what was done on x86, from Sukadev Bhattiprolu. - tracing updates by Steve Rostedt - mostly misc fixes and smaller improvements. - Use perf/event tracing to report PCI Express advanced errors, by Tony Luck. - Enable northbridge performance counters on AMD family 15h, by Jacob Shin. - This tracing commit: tracing: Remove the extra 4 bytes of padding in events changes the ABI. All involved parties (PowerTop in particular) seem to agree that it's safe to do now with the introduction of libtraceevent, but the devil is in the details ... Main tooling side changes: - Add 'event group view', from Namyung Kim: To use it, 'perf record' should group events when recording. And then perf report parses the saved group relation from file header and prints them together if --group option is provided. You can use the 'perf evlist' command to see event group information: $ perf record -e '{ref-cycles,cycles}' noploop 1 [ perf record: Woken up 2 times to write data ] [ perf record: Captured and wrote 0.385 MB perf.data (~16807 samples) ] $ perf evlist --group {ref-cycles,cycles} With this example, default perf report will show you each event separately. You can use --group option to enable event group view: $ perf report --group ... # group: {ref-cycles,cycles} # ======== # Samples: 7K of event 'anon group { ref-cycles, cycles }' # Event count (approx.): 6876107743 # # Overhead Command Shared Object Symbol # ................ ....... ................. .......................... 99.84% 99.76% noploop noploop [.] main 0.07% 0.00% noploop ld-2.15.so [.] strcmp 0.03% 0.00% noploop [kernel.kallsyms] [k] timerqueue_del 0.03% 0.03% noploop [kernel.kallsyms] [k] sched_clock_cpu 0.02% 0.00% noploop [kernel.kallsyms] [k] account_user_time 0.01% 0.00% noploop [kernel.kallsyms] [k] __alloc_pages_nodemask 0.00% 0.00% noploop [kernel.kallsyms] [k] native_write_msr_safe 0.00% 0.11% noploop [kernel.kallsyms] [k] _raw_spin_lock 0.00% 0.06% noploop [kernel.kallsyms] [k] find_get_page 0.00% 0.02% noploop [kernel.kallsyms] [k] rcu_check_callbacks 0.00% 0.02% noploop [kernel.kallsyms] [k] __current_kernel_time As you can see the Overhead column now contains both of ref-cycles and cycles and header line shows group information also - 'anon group { ref-cycles, cycles }'. The output is sorted by period of group leader first. - Initial GTK+ annotate browser, from Namhyung Kim. - Add option for runtime switching perf data file in perf report, just press 's' and a menu with the valid files found in the current directory will be presented, from Feng Tang. - Add support to display whole group data for raw columns, from Jiri Olsa. - Add per processor socket count aggregation in perf stat, from Stephane Eranian. - Add interval printing in 'perf stat', from Stephane Eranian. - 'perf test' improvements - Add support for wildcards in tracepoint system name, from Jiri Olsa. - Add anonymous huge page recognition, from Joshua Zhu. - perf build-id cache now can show DSOs present in a perf.data file that are not in the cache, to integrate with build-id servers being put in place by organizations such as Fedora. - perf top now shares more of the evsel config/creation routines with 'record', paving the way for further integration like 'top' snapshots, etc. - perf top now supports DWARF callchains. - Fix mmap limitations on 32-bit, fix from David Miller. - 'perf bench numa mem' NUMA performance measurement suite - ... and lots of fixes, performance improvements, cleanups and other improvements I failed to list - see the shortlog and git log for details." * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (270 commits) perf/x86/amd: Enable northbridge performance counters on AMD family 15h perf/hwbp: Fix cleanup in case of kzalloc failure perf tools: Fix build with bison 2.3 and older. perf tools: Limit unwind support to x86 archs perf annotate: Make it to be able to skip unannotatable symbols perf gtk/annotate: Fail early if it can't annotate perf gtk/annotate: Show source lines with gray color perf gtk/annotate: Support multiple event annotation perf ui/gtk: Implement basic GTK2 annotation browser perf annotate: Fix warning message on a missing vmlinux perf buildid-cache: Add --update option uprobes/perf: Avoid uprobe_apply() whenever possible uprobes/perf: Teach trace_uprobe/perf code to use UPROBE_HANDLER_REMOVE uprobes/perf: Teach trace_uprobe/perf code to pre-filter uprobes/perf: Teach trace_uprobe/perf code to track the active perf_event's uprobes: Introduce uprobe_apply() perf: Introduce hw_perf_event->tp_target and ->tp_list uprobes/perf: Always increment trace_uprobe->nhit uprobes/tracing: Kill uprobe_trace_consumer, embed uprobe_consumer into trace_uprobe uprobes/tracing: Introduce is_trace_uprobe_enabled() ...
| * | | | uprobes/perf: Avoid uprobe_apply() whenever possibleOleg Nesterov2013-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | uprobe_perf_open/close call the costly uprobe_apply() every time, we can avoid it if: - "nr_systemwide != 0" is not changed. - There is another process/thread with the same ->mm. - copy_proccess() does inherit_event(). dup_mmap() preserves the inserted breakpoints. - event->attr.enable_on_exec == T, we can rely on uprobe_mmap() called by exec/mmap paths. - tp_target is exiting. Only _close() checks PF_EXITING, I don't think TRACE_REG_PERF_OPEN can hit the dying task too often. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| * | | | uprobes/perf: Teach trace_uprobe/perf code to use UPROBE_HANDLER_REMOVEOleg Nesterov2013-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change uprobe_trace_func() and uprobe_perf_func() to return "int". Change uprobe_dispatcher() to return "trace_ret | perf_ret" although this is not needed, currently TP_FLAG_TRACE/TP_FLAG_PROFILE are mutually exclusive. The only functional change is that uprobe_perf_func() checks the filtering too and returns UPROBE_HANDLER_REMOVE if nobody wants to trace current. Testing: # perf probe -x /lib/libc.so.6 syscall # perf record -e probe_libc:syscall -i perl -e 'fork; syscall -1 for 1..10; wait' # perf report --show-total-period 100.00% 10 perl libc-2.8.so [.] syscall Before this patch: # cat /sys/kernel/debug/tracing/uprobe_profile /lib/libc.so.6 syscall 20 A child process doesn't have a counter, but still it hits this breakoint "copied" by dup_mmap(). After the patch: # cat /sys/kernel/debug/tracing/uprobe_profile /lib/libc.so.6 syscall 11 The child process hits this int3 only once and does unapply_uprobe(). Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| * | | | uprobes/perf: Teach trace_uprobe/perf code to pre-filterOleg Nesterov2013-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Finally implement uprobe_perf_filter() which checks ->nr_systemwide or ->perf_events to figure out whether we need to insert the breakpoint. uprobe_perf_open/close are changed to do uprobe_apply(true/false) when the new perf event comes or goes away. Note that currently this is very suboptimal: - uprobe_register() called by TRACE_REG_PERF_REGISTER becomes a heavy nop, consumer->filter() always returns F at this stage. As it was already discussed we need uprobe_register_only() to avoid the costly register_for_each_vma() when possible. - uprobe_apply() is oftenly overkill. Unless "nr_systemwide != 0" changes we need uprobe_apply_mm(), unapply_uprobe() is almost what we need. - uprobe_apply() can be simply avoided sometimes, see the next changes. Testing: # perf probe -x /lib/libc.so.6 syscall # perl -e 'syscall -1 while 1' & [1] 530 # perf record -e probe_libc:syscall perl -e 'syscall -1 for 1..10; sleep 1' # perf report --show-total-period 100.00% 10 perl libc-2.8.so [.] syscall Before this patch: # cat /sys/kernel/debug/tracing/uprobe_profile /lib/libc.so.6 syscall 79291 A huge ->nrhit == 79291 reflects the fact that the background process 530 constantly hits this breakpoint too, even if doesn't contribute to the output. After the patch: # cat /sys/kernel/debug/tracing/uprobe_profile /lib/libc.so.6 syscall 10 This shows that only the target process was punished by int3. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| * | | | uprobes/perf: Teach trace_uprobe/perf code to track the active perf_event'sOleg Nesterov2013-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce "struct trace_uprobe_filter" which records the "active" perf_event's attached to ftrace_event_call. For the start we simply use list_head, we can optimize this later if needed. For example, we do not really need to record an event with ->parent != NULL, we can rely on parent->child_list. And we can certainly do some optimizations for the case when 2 events have the same ->tp_target or tp_target->mm. Change trace_uprobe_register() to process TRACE_REG_PERF_OPEN/CLOSE and add/del this perf_event to the list. We can probably avoid any locking, but lets start with the "obvioulsy correct" trace_uprobe_filter->rwlock which protects everything. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| * | | | uprobes/perf: Always increment trace_uprobe->nhitOleg Nesterov2013-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move tu->nhit++ from uprobe_trace_func() to uprobe_dispatcher(). ->nhit counts how many time we hit the breakpoint inserted by this uprobe, we do not want to loose this info if uprobe was enabled by sys_perf_event_open(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | | | uprobes/tracing: Kill uprobe_trace_consumer, embed uprobe_consumer into ↵Oleg Nesterov2013-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | trace_uprobe trace_uprobe->consumer and "struct uprobe_trace_consumer" add the unnecessary indirection and complicate the code for no reason. This patch simply embeds uprobe_consumer into "struct trace_uprobe", all other changes only fix the compilation errors. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| * | | | uprobes/tracing: Introduce is_trace_uprobe_enabled()Oleg Nesterov2013-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | probe_event_enable/disable() check tu->consumer != NULL to avoid the wrong uprobe_register/unregister(). We are going to kill this pointer and "struct uprobe_trace_consumer", so we add the new helper, is_trace_uprobe_enabled(), which can rely on TP_FLAG_TRACE/TP_FLAG_PROFILE instead. Note: the current logic doesn't look optimal, it is not clear why TP_FLAG_TRACE/TP_FLAG_PROFILE are mutually exclusive, we will probably change this later. Also kill the unused TP_FLAG_UPROBE. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | | | uprobes/tracing: Ensure inode != NULL in create_trace_uprobe()Oleg Nesterov2013-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | probe_event_enable/disable() check tu->inode != NULL at the start. This is ugly, if igrab() can fail create_trace_uprobe() should not succeed and "postpone" the failure. And S_ISREG(inode->i_mode) check added by d24d7dbf is not safe. Note: alloc_uprobe() should probably check igrab() != NULL as well. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | | | uprobes/tracing: Fully initialize uprobe_trace_consumer before uprobe_register()Oleg Nesterov2013-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | probe_event_enable() does uprobe_register() and only after that sets utc->tu and tu->consumer/flags. This can race with uprobe_dispatcher() which can miss these assignments or see them out of order. Nothing really bad can happen, but this doesn't look clean/safe. And this does not allow to use uprobe_consumer->filter() we are going to add, it is called by uprobe_register() and it needs utc->tu. Change this code to initialize everything before uprobe_register(), and reset tu->consumer/flags if it fails. We can't race with event_disable(), the caller holds event_mutex, and if we could the code would be wrong anyway. In fact I think uprobe_trace_consumer should die, it buys nothing but complicates the code. We can simply add uprobe_consumer into trace_uprobe. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | | | uprobes/tracing: Fix dentry/mount leak in create_trace_uprobe()Oleg Nesterov2013-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | create_trace_uprobe() does kern_path() to find ->d_inode, but forgets to do path_put(). We can do this right after igrab(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | | | uprobes: Change handle_swbp() to expose bp_vaddr to handler_chain()Oleg Nesterov2013-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change handle_swbp() to set regs->ip = bp_vaddr in advance, this is what consumer->handler() needs but uprobe_get_swbp_addr() is not exported. This also simplifies the code and makes it more consistent across the supported architectures. handle_swbp() becomes the only caller of uprobe_get_swbp_addr(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
| * | | | uprobes: Kill uprobe_consumer->filter()Oleg Nesterov2013-02-08
| | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | uprobe_consumer->filter() is pointless in its current form, kill it. We will add it back, but with the different signature/semantics. Perhaps we will even re-introduce the callsite in handler_chain(), but not to just skip uc->handler(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| * | | tracing: Init current_trace to nop_trace and remove NULL checksSteven Rostedt (Red Hat)2013-02-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On early boot up, when the ftrace ring buffer is initialized, the static variable current_trace is initialized to &nop_trace. Before this initialization, current_trace is NULL and will never become NULL again. It is always reassigned to a ftrace tracer. Several places check if current_trace is NULL before it uses it, and this check is frivolous, because at the point in time when the checks are made the only way current_trace could be NULL is if ftrace failed its allocations at boot up, and the paths to these locations would probably not be possible. By initializing current_trace to &nop_trace where it is declared, current_trace will never be NULL, and we can remove all these checks of current_trace being NULL which never needed to be checked in the first place. Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | tracing: Make a snapshot feature available from userspaceHiraku Toyooka2013-01-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ftrace has a snapshot feature available from kernel space and latency tracers (e.g. irqsoff) are using it. This patch enables user applictions to take a snapshot via debugfs. Add "snapshot" debugfs file in "tracing" directory. snapshot: This is used to take a snapshot and to read the output of the snapshot. # echo 1 > snapshot This will allocate the spare buffer for snapshot (if it is not allocated), and take a snapshot. # cat snapshot This will show contents of the snapshot. # echo 0 > snapshot This will free the snapshot if it is allocated. Any other positive values will clear the snapshot contents if the snapshot is allocated, or return EINVAL if it is not allocated. Link: http://lkml.kernel.org/r/20121226025300.3252.86850.stgit@liselsia Cc: Jiri Olsa <jolsa@redhat.com> Cc: David Sharp <dhsharp@google.com> Signed-off-by: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com> [ Fixed irqsoff selftest and also a conflict with a change that fixes the update_max_tr. ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | tracing: Replace static old_tracer check of tracer nameHiraku Toyooka2013-01-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the trace buffer read functions use a static variable "old_tracer" for detecting if the current tracer changes. This was suitable for a single trace file ("trace"), but to add a snapshot feature that will use the same function for its file, a check against a static variable is not sufficient. To use the output functions for two different files, instead of storing the current tracer in a static variable, as the trace iterator descriptor contains a pointer to the original current tracer's name, that pointer can now be used to check if the current tracer has changed between different reads of the trace file. Link: http://lkml.kernel.org/r/20121226025252.3252.9276.stgit@liselsia Signed-off-by: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | tracing: Use sched_clock_cpu for trace_clock_globalNamhyung Kim2013-01-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For systems with an unstable sched_clock, all cpu_clock() does is enable/ disable local irq during the call to sched_clock_cpu(). And for stable systems they are same. trace_clock_global() already disables interrupts, so it can call sched_clock_cpu() directly. Link: http://lkml.kernel.org/r/1356576585-28782-2-git-send-email-namhyung@kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ring-buffer: Add stats field for amount read from trace ring bufferSteven Rostedt (Red Hat)2013-01-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a stat about the number of events read from the ring buffer: # cat /debug/tracing/per_cpu/cpu0/stats entries: 39869 overrun: 870512 commit overrun: 0 bytes: 1449912 oldest event ts: 6561.368690 now ts: 6565.246426 dropped events: 0 read events: 112 <-- Added Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | tracing/fgraph: Adjust fgraph depth before calling trace return callbackSteven Rostedt (Red Hat)2013-01-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While debugging the virtual cputime with the function graph tracer with a max_depth of 1 (most common use of the max_depth so far), I found that I was missing kernel execution because of a race condition. The code for the return side of the function has a slight race: ftrace_pop_return_trace(&trace, &ret, frame_pointer); trace.rettime = trace_clock_local(); ftrace_graph_return(&trace); barrier(); current->curr_ret_stack--; The ftrace_pop_return_trace() initializes the trace structure for the callback. The ftrace_graph_return() uses the trace structure for its own use as that structure is on the stack and is local to this function. Then the curr_ret_stack is decremented which is what the trace.depth is set to. If an interrupt comes in after the ftrace_graph_return() but before the curr_ret_stack, then the called function will get a depth of 2. If max_depth is set to 1 this function will be ignored. The problem is that the trace has already been called, and the timestamp for that trace will not reflect the time the function was about to re-enter userspace. Calls to the interrupt will not be traced because the max_depth has prevented this. To solve this issue, the ftrace_graph_return() can safely be moved after the current->curr_ret_stack has been updated. This way the timestamp for the return callback will reflect the actual time. If an interrupt comes in after the curr_ret_stack update and ftrace_graph_return(), it will be traced. It may look a little confusing to see it within the other function, but at least it will not be lost. Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | tracing: Remove second iterator initializerJovi Zhang2013-01-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The trace iterator is already initialized by trace_init_global_iter(), so there is no need to initialize it again. Link: http://lkml.kernel.org/r/CACV3sb+G1YnO6168JhY3dEadmJi58pA5-2cSZT8E0WVHJNFt9Q@mail.gmail.com Signed-off-by: Jovi Zhang <bookjovi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | tracing: Use __this_cpu_inc/dec operation instead of __get_cpu_varShan Wei2013-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __this_cpu_inc_return() or __this_cpu_dec generates a single instruction, which is faster than __get_cpu_var operation. Link: http://lkml.kernel.org/r/50A9C1BD.1060308@gmail.com Reviewed-by: Christoph Lameter <cl@linux.com> Signed-off-by: Shan Wei <davidshan@tencent.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | tracing: Mark tracing_dentry_percpu() staticJosh Triplett2013-01-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nothing outside of kernel/trace/trace.c references tracing_dentry_percpu(). Link: http://lkml.kernel.org/r/1353302917-13995-7-git-send-email-josh@joshtriplett.org Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | tracing: Fix unsigned int compare of zero in recursion checkSteven Rostedt2013-01-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Dan's smatch found a compare bug with the result of the trace_test_and_set_recursion() and comparing to less than zero. If the function fails, it returns -1, but was saved in an unsigned int, which will never be less than zero and will ignore the result of the test if a recursion did happen. Luckily this is the last of the recursion tests, as the infrastructure of ftrace would catch recursions before it got here, except for some few exceptions. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ring-buffer: Remove trace.h from ring_buffer.cSteven Rostedt2013-01-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ring_buffer.c use to require declarations from trace.h, but these have moved to the generic header files. There's nothing in trace.h that ring_buffer.c requires. There's some headers that trace.h included that ring_buffer.c needs, but it's best that it includes them directly, and not include trace.h. Also, some things may use ring_buffer.c without having tracing configured. This removes the dependency that may come in the future. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ring-buffer: User context bit recursion checkingSteven Rostedt2013-01-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using context bit recursion checking, we can help increase the performance of the ring buffer. Before this patch: # echo function > /debug/tracing/current_tracer # for i in `seq 10`; do ./hackbench 50; done Time: 10.285 Time: 10.407 Time: 10.243 Time: 10.372 Time: 10.380 Time: 10.198 Time: 10.272 Time: 10.354 Time: 10.248 Time: 10.253 (average: 10.3012) Now we have: # echo function > /debug/tracing/current_tracer # for i in `seq 10`; do ./hackbench 50; done Time: 9.712 Time: 9.824 Time: 9.861 Time: 9.827 Time: 9.962 Time: 9.905 Time: 9.886 Time: 10.088 Time: 9.861 Time: 9.834 (average: 9.876) a 4% savings! Signed-off-by: Steven Rostedt <rostedt@goodmis.org>