summaryrefslogtreecommitdiffstats
path: root/kernel/trace
AgeCommit message (Collapse)AuthorLines
2011-04-29ftrace: Only update the function code on write to filter filesSteven Rostedt-5/+7
If function tracing is enabled, a read of the filter files will cause the call to stop_machine to update the function trace sites. It should only call stop_machine on write. Cc: stable@kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-27Merge branch 'tip/perf/core' of ↵Ingo Molnar-15/+123
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core Conflicts: include/linux/perf_event.h Merge reason: pick up the latest jump-label enhancements, they are cooked ready. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-27Merge branch 'tip/perf/urgent' of ↵Ingo Molnar-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
2011-04-24sched: Get rid of lock_depthJonathan Corbet-1/+0
Neil Brown pointed out that lock_depth somehow escaped the BKL removal work. Let's get rid of it now. Note that the perf scripting utilities still have a bunch of code for dealing with common_lock_depth in tracepoints; I have left that in place in case anybody wants to use that code with older kernels. Suggested-by: Neil Brown <neilb@suse.de> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110422111910.456c0e84@bike.lwn.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-21ftrace: Build without frame pointers on MicroblazeMichal Simek-1/+1
Microblaze doesn't need/support FRAME_POINTERS in order to have a working function tracer. The patch remove Kconfig warning. Warning log: warning: (LOCKDEP && FAULT_INJECTION_STACKTRACE_FILTER && LATENCYTOP && FUNCTION_TRACER && KMEMCHECK) selects FRAME_POINTER which has unmet direct dependencies (DEBUG_KERNEL && (CRIS || M68K || FRV || UML || AVR32 || SUPERH || BLACKFIN || MN10300) || ARCH_WANT_FRAME_POINTERS) Signed-off-by: Michal Simek <monstr@monstr.eu> Link: http://lkml.kernel.org/r/1301908812-8119-2-git-send-email-monstr@monstr.eu CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Ingo Molnar <mingo@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-16block: make unplug timer trace event correspond to the schedule() unplugJens Axboe-6/+12
It's a pretty close match to what we had before - the timer triggering would mean that nobody unplugged the plug in due time, in the new scheme this matches very closely what the schedule() unplug now is. It's essentially the difference between an explicit unplug (IO unplug) or an implicit unplug (timer unplug, we scheduled with pending IO queued). Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-04-12block: fixup block IO unplug trace callJens Axboe-3/+3
It was removed with the on-stack plugging, readd it and track the depth of requests added when flushing the plug. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-04-12block: remove block_unplug_timer() trace pointJens Axboe-17/+0
We no longer have an unplug timer running, so no point in keeping the trace point. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-04-04tracing: Avoid soft lockup in trace_pipeJiri Olsa-3/+15
running following commands: # enable the binary option echo 1 > ./options/bin # disable context info option echo 0 > ./options/context-info # tracing only events echo 1 > ./events/enable cat trace_pipe plus forcing system to generate many tracing events, is causing lockup (in NON preemptive kernels) inside tracing_read_pipe function. The issue is also easily reproduced by running ltp stress test. (ftrace_stress_test.sh) The reasons are: - bin/hex/raw output functions for events are set to trace_nop_print function, which prints nothing and returns TRACE_TYPE_HANDLED value - LOST EVENT trace do not handle trace_seq overflow These reasons force the while loop in tracing_read_pipe function never to break. The attached patch fixies handling of lost event trace, and changes trace_nop_print to print minimal info, which is needed for the correct tracing_read_pipe processing. v2 changes: - omit the cond_resched changes by trace_nop_print changes - WARN changed to WARN_ONCE and added info to be able to find out the culprit v3 changes: - make more accurate patch comment Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <20110325110518.GC1922@jolsa.brq.redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-04tracing: Print trace_bprintk() formats for modules tooSteven Rostedt-6/+97
The file debugfs/tracing/printk_formats maps the addresses to the formats that are used by trace_bprintk() so that userspace tools can read the buffer and be able to decode trace_bprintk events to get the format saved when reading the ring buffer directly. This is because trace_bprintk() does not store the format into the buffer, but just the address of the format, which is hidden in the kernel memory. But currently it only exports trace_bprintk()s from the kernel core and not for modules. The modules need their formats exported as well. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-04tracing: Convert trace_printk() formats for module to const char *Steven Rostedt-6/+11
The trace_printk() formats for modules do not show up in the debugfs/tracing/printk_formats file. Only the formats that are for trace_printk()s that are in the kernel core. To facilitate the change to add trace_printk() formats from modules into that file as well, we need to convert the structure that holds the formats from char fmt[], into const char *fmt, and allocate them separately. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-31Fix common misspellingsLucas De Marchi-10/+10
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-25Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds-2/+1
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, x86: Complain louder about BIOSen corrupting CPU/PMU state and continue perf, x86: P4 PMU - Read proper MSR register to catch unflagged overflows perf symbols: Look at .dynsym again if .symtab not found perf build-id: Add quirk to deal with perf.data file format breakage perf session: Pass evsel in event_ops->sample() perf: Better fit max unprivileged mlock pages for tools needs perf_events: Fix stale ->cgrp pointer in update_cgrp_time_from_cpuctx() perf top: Fix uninitialized 'counter' variable tracing: Fix set_ftrace_filter probe function display perf, x86: Fix Intel fixed counters base initialization
2011-03-24Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds-11/+4
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits) Documentation/iostats.txt: bit-size reference etc. cfq-iosched: removing unnecessary think time checking cfq-iosched: Don't clear queue stats when preempt. blk-throttle: Reset group slice when limits are changed blk-cgroup: Only give unaccounted_time under debug cfq-iosched: Don't set active queue in preempt block: fix non-atomic access to genhd inflight structures block: attempt to merge with existing requests on plug flush block: NULL dereference on error path in __blkdev_get() cfq-iosched: Don't update group weights when on service tree fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away block: Require subsystems to explicitly allocate bio_set integrity mempool jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging fs: make fsync_buffers_list() plug mm: make generic_writepages() use plugging blk-cgroup: Add unaccounted time to timeslice_used. block: fixup plugging stubs for !CONFIG_BLOCK block: remove obsolete comments for blkdev_issue_zeroout. blktrace: Use rq->cmd_flags directly in blk_add_trace_rq. ... Fix up conflicts in fs/{aio.c,super.c}
2011-03-23Merge branch 'tip/perf/urgent' of ↵Ingo Molnar-2/+1
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
2011-03-22tracing: Fix set_ftrace_filter probe function displayJiri Olsa-2/+1
If one or more function probes (like traceon) are enabled, and there's no other function filter, the first probe func is skipped (which one depends on the position in the hash). $ echo sys_open:traceon sys_close:traceon > ./set_ftrace_filter $ cat set_ftrace_filter #### all functions enabled #### sys_close:traceon:unlimited $ The reason was, that in the case of no other function filter, the func_pos was not properly updated before calling t_hash_start. Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <1297874134-7008-1-git-send-email-jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-18Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds-3/+3
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: (30 commits) trace, filters: Initialize the match variable in process_ops() properly trace, documentation: Fix branch profiling location in debugfs oprofile, s390: Cleanups oprofile, s390: Remove hwsampler_files.c and merge it into init.c perf: Fix tear-down of inherited group events perf: Reorder & optimize perf_event_context to remove alignment padding on 64 bit builds perf: Handle stopped state with tracepoints perf: Fix the software events state check perf, powerpc: Handle events that raise an exception without overflowing perf, x86: Use INTEL_*_CONSTRAINT() for all PEBS event constraints perf, x86: Clean up SandyBridge PEBS events perf lock: Fix sorting by wait_min perf tools: Version incorrect with some versions of grep perf evlist: New command to list the names of events present in a perf.data file perf script: Add support for H/W and S/W events perf script: Add support for dumping symbols perf script: Support custom field selection for output perf script: Move printing of 'common' data from print_event and rename perf tracing: Remove print_graph_cpu and print_graph_proc from trace-event-parse perf script: Change process_event prototype ...
2011-03-18Merge branch 'for-linus' of ↵Linus Torvalds-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (47 commits) doc: CONFIG_UNEVICTABLE_LRU doesn't exist anymore Update cpuset info & webiste for cgroups dcdbas: force SMI to happen when expected arch/arm/Kconfig: remove one to many l's in the word. asm-generic/user.h: Fix spelling in comment drm: fix printk typo 'sracth' Remove one to many n's in a word Documentation/filesystems/romfs.txt: fixing link to genromfs drivers:scsi Change printk typo initate -> initiate serial, pch uart: Remove duplicate inclusion of linux/pci.h header fs/eventpoll.c: fix spelling mm: Fix out-of-date comments which refers non-existent functions drm: Fix printk typo 'failled' coh901318.c: Change initate to initiate. mbox-db5500.c Change initate to initiate. edac: correct i82975x error-info reported edac: correct i82975x mci initialisation edac: correct commented info fs: update comments to point correct document target: remove duplicate include of target/target_core_device.h from drivers/target/target_core_hba.c ... Trivial conflict in fs/eventpoll.c (spelling vs addition)
2011-03-18trace, filters: Initialize the match variable in process_ops() properlyIngo Molnar-1/+1
Make sure the 'match' variable always has a value. Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-17trace, documentation: Fix branch profiling location in debugfsDavid Rientjes-2/+2
The debugfs interface for branch profiling is through /sys/kernel/debug/tracing/trace_stat/branch_annotated /sys/kernel/debug/tracing/trace_stat/branch_all so update the Kconfig accordingly. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <alpine.DEB.2.00.1103161716320.11407@chino.kir.corp.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-11blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.Tao Ma-11/+4
In blk_add_trace_rq, we only chose the minor 2 bits from request's cmd_flags and did some check for discard. so most of other flags(e.g, REQ_SYNC) are missing. For example, with a sync write after blkparse we get: 8,16 1 1 0.001776503 7509 A WS 1349632 + 1024 <- (8,17) 1347584 8,16 1 2 0.001776813 7509 Q WS 1349632 + 1024 [dd] 8,16 1 3 0.001780395 7509 G WS 1349632 + 1024 [dd] 8,16 1 5 0.001783186 7509 I W 1349632 + 1024 [dd] 8,16 1 11 0.001816987 7509 D W 1349632 + 1024 [dd] 8,16 0 2 0.006218192 0 C W 1349632 + 1024 [0] Since now we have integrated the flags of both bio and request, it is safe to pass rq->cmd_flags directly to __blk_add_trace. With this patch, after a sync write we get: 8,16 1 1 0.001776900 5425 A WS 1189888 + 1024 <- (8,17) 1187840 8,16 1 2 0.001777179 5425 Q WS 1189888 + 1024 [dd] 8,16 1 3 0.001780797 5425 G WS 1189888 + 1024 [dd] 8,16 1 5 0.001783402 5425 I WS 1189888 + 1024 [dd] 8,16 1 11 0.001817468 5425 D WS 1189888 + 1024 [dd] 8,16 0 2 0.005640709 0 C WS 1189888 + 1024 [0] Signed-off-by: Tao Ma <boyu.mt@taobao.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10tracing: Fix irqoff selftest expanding max bufferSteven Rostedt-0/+9
If the kernel command line declares a tracer "ftrace=sometracer" and that tracer is either not defined or is enabled after irqsoff, then the irqs off selftest will fail with the following error: Testing tracer irqsoff: ------------[ cut here ]------------ WARNING: at /home/rostedt/work/autotest/nobackup/linux-test.git/kernel/trace/tra ce.c:713 update_max_tr_single+0xfa/0x11b() Hardware name: Modules linked in: Pid: 1, comm: swapper Not tainted 2.6.38-rc8-test #1 Call Trace: [<c0441d9d>] ? warn_slowpath_common+0x65/0x7a [<c049adb2>] ? update_max_tr_single+0xfa/0x11b [<c0441dc1>] ? warn_slowpath_null+0xf/0x13 [<c049adb2>] ? update_max_tr_single+0xfa/0x11b [<c049e454>] ? stop_critical_timing+0x154/0x204 [<c049b54b>] ? trace_selftest_startup_irqsoff+0x5b/0xc1 [<c049b54b>] ? trace_selftest_startup_irqsoff+0x5b/0xc1 [<c049b54b>] ? trace_selftest_startup_irqsoff+0x5b/0xc1 [<c049e529>] ? time_hardirqs_on+0x25/0x28 [<c0468bca>] ? trace_hardirqs_on_caller+0x18/0x12f [<c0468cec>] ? trace_hardirqs_on+0xb/0xd [<c049b54b>] ? trace_selftest_startup_irqsoff+0x5b/0xc1 [<c049b6b8>] ? register_tracer+0xf8/0x1a3 [<c14e93fe>] ? init_irqsoff_tracer+0xd/0x11 [<c040115e>] ? do_one_initcall+0x71/0x121 [<c14e93f1>] ? init_irqsoff_tracer+0x0/0x11 [<c14ce3a9>] ? kernel_init+0x13a/0x1b6 [<c14ce26f>] ? kernel_init+0x0/0x1b6 [<c0403842>] ? kernel_thread_helper+0x6/0x10 ---[ end trace e93713a9d40cd06c ]--- .. no entries found ..FAILED! What happens is the "ftrace=..." will expand the ring buffer to its default size (from its minimum size) but it will not expand the max ring buffer (the ring buffer to store maximum latencies). When the irqsoff test runs, it will call the ring buffer swap routine that checks if the max ring buffer is the same size as the normal ring buffer, and will fail if it is not. This causes the test to fail. The solution is to expand the max ring buffer before running the self test if the max ring buffer is used by that tracer and the normal ring buffer is expanded. The max ring buffer should be shrunk again after the test is done to save space. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-10tracing: Align 4 byte ints together in struct tracerSteven Rostedt-1/+1
Move elements in struct tracer for better alignment. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-10tracing: Export trace_set_clr_event()Yuanhan Liu-0/+1
Trace events belonging to a module only exists when the module is loaded. Well, we can use trace_set_clr_event funtion to enable some trace event at the module init routine, so that we will not miss something while loading then module. So, Export the trace_set_clr_event function so that module can use it. Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> LKML-Reference: <1289196312-25323-1-git-send-email-yuanhan.liu@linux.intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-10tracing: Explain about unstable clock on resume with ring buffer warningJiri Olsa-2/+10
The "Delta way too big" warning might appear on a system with a unstable shed clock right after the system is resumed and tracing was enabled at time of suspend. Since it's not realy a bug, and the unstable sched clock is working fast and reliable otherwise, Steven suggested to keep using the sched clock in any case and just to make note in the warning itself. v2 changes: - added #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <20110218145219.GD2604@jolsa.brq.redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-10tracing: Adjust conditional expression latency formatting.David Sharp-8/+18
Formatting change only to improve code readability. No code changes except to introduce intermediate variables. Signed-off-by: David Sharp <dhsharp@google.com> LKML-Reference: <1291421609-14665-13-git-send-email-dhsharp@google.com> [ Keep variable declarations and assignment separate ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-10tracing: Fix event alignment: ftrace:context_switch and ftrace:wakeupDavid Sharp-3/+3
Signed-off-by: David Sharp <dhsharp@google.com> LKML-Reference: <1291421609-14665-6-git-send-email-dhsharp@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-10tracing: Remove lock_depth from event entrySteven Rostedt-14/+5
The lock_depth field in the event headers was added as a temporary data point for help in removing the BKL. Now that the BKL is pretty much been removed, we can remove this field. This in turn changes the header from 12 bytes to 8 bytes, removing the 4 byte buffer that gcc would insert if the first field in the data load was 8 bytes in size. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-09ring-buffer: Remove unused #include <linux/trace_irq.h>David Sharp-1/+0
Signed-off-by: David Sharp <dhsharp@google.com> LKML-Reference: <1291421609-14665-3-git-send-email-dhsharp@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-09tracing: Add an 'overwrite' trace_option.David Sharp-6/+23
Add an "overwrite" trace_option for ftrace to control whether the buffer should be overwritten on overflow or not. The default remains to overwrite old events when the buffer is full. This patch adds the option to instead discard newest events when the buffer is full. This is useful to get a snapshot of traces just after enabling traces. Dropping the current event is also a simpler code path. Signed-off-by: David Sharp <dhsharp@google.com> LKML-Reference: <1291844807-15481-1-git-send-email-dhsharp@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-08Merge commit 'v2.6.38-rc8' into perf/coreIngo Molnar-16/+0
Merge reason: Merge latest fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-03blktrace: Remove blk_fill_rwbs_rq.Tao Ma-16/+0
If we enable trace events to trace block actions, We use blk_fill_rwbs_rq to analyze the corresponding actions in request's cmd_flags, but we only choose the minor 2 bits from it, so most of other flags(e.g, REQ_SYNC) are missing. For example, with a sync write we get: write_test-2409 [001] 160.013869: block_rq_insert: 3,64 W 0 () 258135 + = 8 [write_test] Since now we have integrated the flags of both bio and request, it is safe to pass rq->cmd_flags directly to blk_fill_rwbs and blk_fill_rwbs_rq isn't needed any more. With this patch, after a sync write we get: write_test-2417 [000] 226.603878: block_rq_insert: 3,64 WS 0 () 258135 += 8 [write_test] Signed-off-by: Tao Ma <boyu.mt@taobao.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-03Merge branch '/tip/perf/filter' of ↵Frederic Weisbecker-169/+754
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git into perf/core
2011-02-18Revert "tracing: Add unstable sched clock note to the warning"Ingo Molnar-6/+2
This reverts commit 5e38ca8f3ea423442eaafe1b7e206084aa38120a. Breaks the build of several !CONFIG_HAVE_UNSTABLE_SCHED_CLOCK architectures. Cc: Jiri Olsa <jolsa@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Message-ID: <20110217171823.GB17058@elte.hu> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-17Merge branch 'tip/perf/core' of ↵Ingo Molnar-62/+40
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
2011-02-16Merge branch 'perf/urgent' into perf/coreIngo Molnar-0/+7
Merge reason: we need to queue up dependent patch Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-15Merge branch 'master' into for-nextJiri Kosina-47/+38
2011-02-14Merge branch 'tip/perf/urgent' of ↵Ingo Molnar-7/+45
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
2011-02-14tracing/kprobe: Fix NULL pointer deref checkMasami Hiramatsu-1/+1
Add NULL check for avoiding NULL pointer deref. This bug has been introduced by: 1ff511e35ed8: tracing/kprobes: Add bitfield type which causes a null pointer dereference bug when kprobe-tracer parses an argument without type. Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: 2nddept-manager@sdl.hitachi.co.jp Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110214054807.8919.69740.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Ingo Molnar <mingo@elte.hu> Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
2011-02-11ftrace: Fix memory leak with function graph and cpu hotplugSteven Rostedt-7/+45
When the fuction graph tracer starts, it needs to make a special stack for each task to save the real return values of the tasks. All running tasks have this stack created, as well as any new tasks. On CPU hot plug, the new idle task will allocate a stack as well when init_idle() is called. The problem is that cpu hotplug does not create a new idle_task. Instead it uses the idle task that existed when the cpu went down. ftrace_graph_init_task() will add a new ret_stack to the task that is given to it. Because a clone will make the task have a stack of its parent it does not check if the task's ret_stack is already NULL or not. When the CPU hotplug code starts a CPU up again, it will allocate a new stack even though one already existed for it. The solution is to treat the idle_task specially. In fact, the function_graph code already does, just not at init_idle(). Instead of using the ftrace_graph_init_task() for the idle task, which that function expects the task to be a clone, have a separate ftrace_graph_init_idle_task(). Also, we will create a per_cpu ret_stack that is used by the idle task. When we call ftrace_graph_init_idle_task() it will check if the idle task's ret_stack is NULL, if it is, then it will assign it the per_cpu ret_stack. Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stable Tree <stable@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-09Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds-0/+7
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: cdrom: support devices that have check_events but not media_changed cfq-iosched: Don't wait if queue already has requests. blkio-throttle: Avoid calling blkiocg_lookup_group() for root group cfq: rename a function to give it more appropriate name cciss: make cciss_revalidate not loop through CISS_MAX_LUNS volumes unnecessarily. drivers/block/aoe/Makefile: replace the use of <module>-objs with <module>-y loop: queue_lock NULL pointer derefence in blk_throtl_exit drivers/block/Makefile: replace the use of <module>-objs with <module>-y blktrace: Don't output messages if NOTIFY isn't set.
2011-02-08tracing: Deprecate tracing_enabled for tracing_onSteven Rostedt-0/+4
tracing_enabled should not be used, it is heavy weight and does not do much in helping lower the overhead. tracing_on should be used instead. Warn users to use tracing_on when tracing_enabled is used as it will soon be removed from the tracing directory. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-08tracing: Remove obsolete sched_switch tracerSteven Rostedt-48/+0
The trace events sched_switch and sched_wakeup do the same thing as the stand alone sched_switch tracer does. It is no longer needed. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-08tracing: Add unstable sched clock note to the warningJiri Olsa-2/+6
The warning "Delta way too big" warning might appear on a system with unstable shed clock right after the system is resumed and tracing was enabled during the suspend. Since it's not realy bug, and the unstable sched clock is working fast and reliable otherwise, Steven suggested to keep using the sched clock in any case and just to make note in the warning itself. Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <1296649698-6003-1-git-send-email-jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/syscalls: Early terminate search for sys_ni_syscallIan Munsie-0/+3
Many system calls are unimplemented and mapped to sys_ni_syscall, but at boot ftrace would still search through every syscall metadata entry for a match which wouldn't be there. This patch adds causes the search to terminate early if the system call is not mapped. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> LKML-Reference: <1296703645-18718-7-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/syscalls: Allow arch specific syscall symbol matchingIan Munsie-7/+14
Some architectures have unusual symbol names and the generic code to match the symbol name with the function name for the syscall metadata will fail. For example, symbols on PPC64 start with a period and the generic code will fail to match them. This patch moves the match logic out into a separate function which an arch can override by defining ARCH_HAS_SYSCALL_MATCH_SYM_NAME in asm/ftrace.h and implementing arch_syscall_match_sym_name. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> LKML-Reference: <1296703645-18718-5-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/syscalls: Make arch_syscall_addr weakIan Munsie-1/+1
Some architectures use non-trivial system call tables and will not work with the generic arch_syscall_addr code. For example, PowerPC64 uses a table of twin long longs. This patch makes the generic arch_syscall_addr weak to allow architectures with non-trivial system call tables to override it. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> LKML-Reference: <1296703645-18718-4-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/syscalls: Convert redundant syscall_nr checks into WARN_ONIan Munsie-4/+4
With the ftrace events now checking if the syscall_nr is valid upon initialisation it should no longer be possible to register or unregister a syscall event without a valid syscall_nr since they should not be created. This adds a WARN_ON_ONCE in the register and unregister functions to locate potential regressions in the future. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> LKML-Reference: <1296703645-18718-3-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/syscalls: Don't add events for unmapped syscallsIan Munsie-0/+8
FTRACE_SYSCALLS would create events for each and every system call, even if it had failed to map the system call's name with it's number. This resulted in a number of events being created that would not behave as expected. This could happen, for example, on architectures who's symbol names are unusual and will not match the system call name. It could also happen with system calls which were mapped to sys_ni_syscall. This patch changes the default system call number in the metadata to -1. If the system call name from the metadata is not successfully mapped to a system call number during boot, than the event initialisation routine will now return an error, preventing the event from being created. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> LKML-Reference: <1296703645-18718-2-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Remove synchronize_sched() from __alloc_preds()Steven Rostedt-23/+7
Because the filters are processed first and then activated (added to the call), we no longer need to worry about the preds of the filter in __alloc_preds() being used. As the filter that is allocating preds is not activated yet. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>