1. 24 Mar, 2009 2 commits
    • Steven Rostedt's avatar
      function-graph: moved the timestamp from arch to generic code · 5d1a03dc
      Steven Rostedt authored
      
      
      This patch move the timestamp from happening in the arch specific
      code into the general code. This allows for better control by the tracer
      to time manipulation.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      5d1a03dc
    • Steven Rostedt's avatar
      tracing: fix memory leak in trace_stat · 09833521
      Steven Rostedt authored
      
      
      If the function profiler does not have any items recorded and one were
      to cat the function stat file, the kernel would take a BUG with a NULL
      pointer dereference.
      
      Looking further into this, I found that returning NULL from stat_start
      did not stop the stat logic, and would later call stat_next. This breaks
      from the way seq_file works, so I looked into fixing the stat code.
      
      This is where I noticed that the last next_entry is never freed.
      It is allocated, and if the stat_next returns NULL, the code breaks out
      of the loop, unlocks the mutex and exits. We never link the next_entry
      nor do we free it. Thus it is a real memory leak.
      
      This patch rearranges the code a bit to not only fix the memory leak,
      but also to act more like seq_file where nothing is printed if there
      is nothing to print. That is, stat_start returns NULL.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      09833521
  2. 23 Mar, 2009 2 commits
    • Anton Vorontsov's avatar
      tracing: Fix TRACING_SUPPORT dependency for PPC32 · 45b95608
      Anton Vorontsov authored
      commit 40ada30f
      
       ("tracing: clean up menu"),
      despite the "clean up" in its purpose, introduced a behavioural
      change for Kconfig symbols: we no longer able to select tracing
      support on PPC32 (because IRQFLAGS_SUPPORT isn't yet implemented).
      
      The IRQFLAGS_SUPPORT is not mandatory for most tracers, tracing core
      has a special case for platforms w/o irqflags (which, by the way, has
      become useless as of the commit above).
      
      Though according to Ingo Molnar, there was periodic build failures on
      weird, unmaintained architectures that had no irqflags-tracing support
      and hence didn't know the raw_irqs_save/restore primitives. Thus we'd
      better not enable irqflags-less tracing for all architectures.
      
      This patch restores the old behaviour for PPC32, and thus brings the
      tracing back. Other architectures can either add themselves to the
      exception list or (better) implement TRACE_IRQFLAGS_SUPPORT.
      Signed-off-by: default avatarAnton Vorontsov <avorontsov@ru.mvista.com>
      Acked-b: Steven Rostedt <rostedt@goodmis.org>
      Cc: linuxppc-dev@ozlabs.org
      LKML-Reference: <20090323220724.GA9851@oksana.dev.rtsoft.ru>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      45b95608
    • Frederic Weisbecker's avatar
      tracing/ftrace: check if debugfs is registered before creating files · 3e1f60b8
      Frederic Weisbecker authored
      
      
      Impact: fix a crash with ftrace={nop,boot} parameter
      
      If the nop or initcall tracers are launched as boot tracers,
      they will attempt to create their option directory and files.
      But these tracers are registered very early and then assigned
      as "boot tracers" very early if asked to.
      
      Since they do this before debugfs has been registered (core initcall),
      a crash is triggered.
      
      Another early tracers could also come later. So we fix it by
      checking if debugfs is initialized before creating the root
      tracing directory.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Greg Kroah-Hartman <gregkh@suse.de>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      LKML-Reference: <1237759847-21025-3-git-send-email-fweisbec@gmail.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      3e1f60b8
  3. 22 Mar, 2009 3 commits
    • Dmitri Vorobiev's avatar
      tracing: fix four sparse warnings · b8b94265
      Dmitri Vorobiev authored
      
      
      Impact: cleanup.
      
      This patch fixes the following sparse warnings:
      
       kernel/trace/trace.c:385:9: warning: symbol 'trace_seq_to_buffer' was
       not declared. Should it be static?
      
       kernel/trace/trace_clock.c:29:13: warning: symbol 'trace_clock_local'
       was not declared. Should it be static?
      
       kernel/trace/trace_clock.c:54:13: warning: symbol 'trace_clock' was not
       declared. Should it be static?
      
       kernel/trace/trace_clock.c:74:13: warning: symbol 'trace_clock_global'
       was not declared. Should it be static?
      Signed-off-by: default avatarDmitri Vorobiev <dmitri.vorobiev@movial.com>
      LKML-Reference: <1237741871-5827-4-git-send-email-dmitri.vorobiev@movial.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      b8b94265
    • Frederic Weisbecker's avatar
      tracing: keep the tracing buffer after self-test failure · 0cf53ff6
      Frederic Weisbecker authored
      
      
      Instead of using ftrace_dump_on_oops, it's far more convenient
      to have the trace leading up to a self-test failure available
      in /debug/tracing/trace.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      LKML-Reference: <1237694675-23509-1-git-send-email-fweisbec@gmail.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      0cf53ff6
    • Frederic Weisbecker's avatar
      tracing/function-graph-tracer: prevent hangs during self-tests · cf586b61
      Frederic Weisbecker authored
      
      
      Impact: detect tracing related hangs
      
      Sometimes, with some configs, the function graph tracer can make
      the timer interrupt too much slow, hanging the kernel in an endless
      loop of timer interrupts servicing.
      
      As suggested by Ingo, this patch brings a watchdog which stops the
      selftest after a defined number of functions traced, definitely
      disabling this tracer.
      
      For those who want to debug the cause of the function graph trace
      hang, you can pass the ftrace_dump_on_oops kernel parameter to dump
      the traces after this hang detection.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      LKML-Reference: <1237694675-23509-1-git-send-email-fweisbec@gmail.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      cf586b61
  4. 21 Mar, 2009 1 commit
    • Frederic Weisbecker's avatar
      tracing/ring-buffer: don't annotate rb_cpu_notify with __cpuinit · 09c9e84d
      Frederic Weisbecker authored
      
      
      Impact: remove a section warning
      
      CONFIG_DEBUG_SECTION_MISMATCH raises the following warning on -tip:
      
        WARNING: kernel/trace/built-in.o(.text+0x5bc5): Section mismatch in
        reference from the function ring_buffer_alloc() to the function
        .cpuinit.text:rb_cpu_notify()
        The function ring_buffer_alloc() references
        the function __cpuinit rb_cpu_notify().
      
      This is actually harmless. The code in the ring buffer don't build
      rb_cpu_notify and other cpu hotplug stuffs when !CONFIG_HOTPLUG_CPU
      so we have no risk to reference freed memory here (it would even
      be harmless if we unconditionally build it because register_cpu_notifier
      would do nothing when !CONFIG_HOTPLUG_CPU.
      
      But since ring_buffer_alloc() can be called everytime, we don't want it
      to be annotated with __cpuinit so we drop the __cpuinit from
      rb_cpu_notify.
      
      This is not a waste of memory because it is only defined and used on
      CONFIG_HOTPLUG_CPU.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      LKML-Reference: <1237606416-22268-1-git-send-email-fweisbec@gmail.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      09c9e84d
  5. 20 Mar, 2009 3 commits
  6. 19 Mar, 2009 6 commits
    • Steven Rostedt's avatar
      function-graph: show binary events as comments · 5087f8d2
      Steven Rostedt authored
      
      
      With the added TRACE_EVENT macro, the events no longer appear in
      the function graph tracer. This was because the function graph
      did not know how to display the entries. The graph tracer was
      only aware of its own entries and the printk entries.
      
      By using the event call back feature, the graph tracer can now display
      the events.
      
       # echo irq > /debug/tracing/set_event
      
      Which can show:
      
       0)               |          handle_IRQ_event() {
       0)               |            /* irq_handler_entry: irq=48 handler=eth0 */
       0)               |            e1000_intr() {
       0)   0.926 us    |              __napi_schedule();
       0)   3.888 us    |            }
       0)               |            /* irq_handler_exit: irq=48 return=handled */
       0)   0.655 us    |            runqueue_is_locked();
       0)               |            __wake_up() {
       0)   0.831 us    |              _spin_lock_irqsave();
      
      The irq entry and exit events show up as comments.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      5087f8d2
    • Steven Rostedt's avatar
      tracing: remove recording function depth from trace_printk · 40ce74f1
      Steven Rostedt authored
      
      
      The function depth in trace_printk was to facilitate the function
      graph output. Now that the function graph calculates the depth within
      the trace output, we no longer need to record the depth when the
      trace_printk is called.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      40ce74f1
    • Steven Rostedt's avatar
      function-graph: calculate function depth within function graph tracer · 2fbcdb35
      Steven Rostedt authored
      
      
      Currently, the function graph tracer depends on the trace_printk
      to record the depth. All the information is already there in the trace
      to calculate function depth, with the exception of having the printk
      be the first item. But as soon as a entry or exit is reached, then
      we know the depth.
      
      This patch changes the iter->private data from recording a per cpu
      last_pid, to a structure that holds both the last_pid and the current
      depth. This data is used to determine the function depth for the
      printks.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      2fbcdb35
    • Steven Rostedt's avatar
      tracing: make print_(b)printk_msg_only global · 5ef841f6
      Steven Rostedt authored
      
      
      This patch makes print_printk_msg_only and print_bprintk_msg_only
      global for other functions to use. It also renames them by adding
      a "trace_" to the beginning to avoid namespace collisions.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      5ef841f6
    • Frederic Weisbecker's avatar
      tracing/ring-buffer: fix non cpu hotplug case · 3bf832ce
      Frederic Weisbecker authored
      
      
      Impact: fix warning with irqsoff tracer
      
      The ring buffer allocates its buffers on pre-smp time (early_initcall).
      It means that, at first, only the boot cpu buffer is allocated and
      the ring-buffer cpumask only has the boot cpu set (cpu_online_mask).
      
      Later, the secondary cpu will show up and the ring-buffer will be notified
      about this event: the appropriate buffer will be allocated and the cpumask
      will be updated.
      
      Unfortunately, if !CONFIG_CPU_HOTPLUG, the ring-buffer will not be
      notified about the secondary cpus, meaning that the cpumask will have
      only the cpu boot set, and only one cpu buffer allocated.
      
      We fix that by using cpu_possible_mask if !CONFIG_CPU_HOTPLUG.
      
      This patch fixes the following warning with irqsoff tracer running:
      
      [  169.317794] WARNING: at kernel/trace/trace.c:466 update_max_tr_single+0xcc/0xf3()
      [  169.318002] Hardware name: AMILO Li 2727
      [  169.318002] Modules linked in:
      [  169.318002] Pid: 5624, comm: bash Not tainted 2.6.29-rc8-tip-02636-g6aafa6c #11
      [  169.318002] Call Trace:
      [  169.318002]  [<ffffffff81036182>] warn_slowpath+0xea/0x13d
      [  169.318002]  [<ffffffff8100b9d6>] ? ftrace_call+0x5/0x2b
      [  169.318002]  [<ffffffff8100b9d6>] ? ftrace_call+0x5/0x2b
      [  169.318002]  [<ffffffff8100b9d1>] ? ftrace_call+0x0/0x2b
      [  169.318002]  [<ffffffff8101ef10>] ? ftrace_modify_code+0xa9/0x108
      [  169.318002]  [<ffffffff8106e27f>] ? trace_hardirqs_off+0x25/0x27
      [  169.318002]  [<ffffffff8149afe7>] ? _spin_unlock_irqrestore+0x1f/0x2d
      [  169.318002]  [<ffffffff81064f52>] ? ring_buffer_reset_cpu+0xf6/0xfb
      [  169.318002]  [<ffffffff8106637c>] ? ring_buffer_reset+0x36/0x48
      [  169.318002]  [<ffffffff8106aeda>] update_max_tr_single+0xcc/0xf3
      [  169.318002]  [<ffffffff8100bc17>] ? sysret_check+0x22/0x5d
      [  169.318002]  [<ffffffff8106e3ea>] stop_critical_timing+0x142/0x204
      [  169.318002]  [<ffffffff8106e4cf>] trace_hardirqs_on_caller+0x23/0x25
      [  169.318002]  [<ffffffff8149ac28>] trace_hardirqs_on_thunk+0x3a/0x3c
      [  169.318002]  [<ffffffff8100bc17>] ? sysret_check+0x22/0x5d
      [  169.318002] ---[ end trace db76cbf775a750cf ]---
      
      Because this tracer may try to swap two cpu ring buffers for an
      unregistered cpu on the ring buffer.
      
      This patch might also fix a fair loss of traces due to unallocated buffers
      for secondary cpus.
      Reported-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Acked-b: Steven Rostedt <rostedt@goodmis.org>
      LKML-Reference: <1237470453-5427-1-git-send-email-fweisbec@gmail.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      3bf832ce
    • Steven Rostedt's avatar
      function-graph: consolidate prologues for output · ac5f6c96
      Steven Rostedt authored
      
      
      Impact: clean up
      
      The prologue of the function graph entry, return and comments all
      start out pretty much the same. Each of these duplicate code and
      do so slightly differently.
      
      This patch consolidates the printing of the pid, absolute time,
      cpu and proc (and for entry, the interrupt).
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      ac5f6c96
  7. 18 Mar, 2009 10 commits
    • Steven Rostedt's avatar
      tracing: give easy way to clear trace buffer · 4acd4d00
      Steven Rostedt authored
      
      
      There is currently no easy way to clear the trace buffer. Currently
      the only way is to change the current tracer.
      
      This patch lets the user clear the trace buffer by simply writing
      into the trace files.
      
       echo > /debug/tracing/trace
      
      or to clear a single cpu (i.e. for CPU 1):
      
       echo > /debug/tracing/per_cpu/cpu1/trace
      Requested-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      4acd4d00
    • Frederic Weisbecker's avatar
      tracing/ftrace: stop {irqs, preempt}soff tracers when tracing is stopped · 49036200
      Frederic Weisbecker authored
      
      
      Impact: fix a selftest warning
      
      In some cases, it's possible to see the following warning on irqsoff
      tracer selftest:
      
      [    4.640003] Testing tracer irqsoff: <4>------------[ cut here ]------------
      [    4.653562] WARNING: at kernel/trace/trace.c:458 update_max_tr_single+0x9a/0xc4()
      [    4.660000] Hardware name: System Product Name
      [    4.660000] Modules linked in:
      [    4.660000] Pid: 301, comm: kstop/1 Not tainted 2.6.29-rc8-tip #35837
      [    4.660000] Call Trace:
      [    4.660000]  [<4014b588>] warn_slowpath+0x79/0x8f
      [    4.660000]  [<402d6949>] ? put_dec+0x64/0x6b
      [    4.660000]  [<40162b56>] ? getnstimeofday+0x58/0xdd
      [    4.660000]  [<40162210>] ? clocksource_read+0x3/0xf
      [    4.660000]  [<4015eb44>] ? ktime_set+0x8/0x34
      [    4.660000]  [<4014101a>] ? balance_runtime+0x8/0x56
      [    4.660000]  [<405f6f11>] ? _spin_lock+0x3/0x10
      [    4.660000]  [<4011f643>] ? ftrace_call+0x5/0x8
      [    4.660000]  [<4015d0f1>] ? task_cputime_zero+0x3/0x27
      [    4.660000]  [<40190ee7>] ? cpupri_set+0x90/0xcb
      [    4.660000]  [<405f7208>] ? _spin_lock_irqsave+0x22/0x34
      [    4.660000]  [<40190f12>] ? cpupri_set+0xbb/0xcb
      [    4.660000]  [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35
      [    4.660000]  [<4018493f>] ? ring_buffer_reset_cpu+0x27/0x51
      [    4.660000]  [<405f7208>] ? _spin_lock_irqsave+0x22/0x34
      [    4.660000]  [<40184962>] ? ring_buffer_reset_cpu+0x4a/0x51
      [    4.660000]  [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35
      [    4.660000]  [<4018cc29>] ? trace_hardirqs_off+0x1a/0x1c
      [    4.660000]  [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35
      [    4.660000]  [<40184962>] ? ring_buffer_reset_cpu+0x4a/0x51
      [    4.660000]  [<401850f3>] ? cpumask_next+0x15/0x18
      [    4.660000]  [<4018a41f>] update_max_tr_single+0x9a/0xc4
      [    4.660000]  [<4014e5fe>] ? exit_notify+0x16/0xf2
      [    4.660000]  [<4018cd13>] check_critical_timing+0xcc/0x11e
      [    4.660000]  [<4014e5fe>] ? exit_notify+0x16/0xf2
      [    4.660000]  [<4014e5fe>] ? exit_notify+0x16/0xf2
      [    4.660000]  [<4018cdf1>] stop_critical_timing+0x8c/0x9f
      [    4.660000]  [<4014e5c4>] ? forget_original_parent+0xac/0xd0
      [    4.660000]  [<4018ce3a>] trace_hardirqs_on+0x1a/0x1c
      [    4.660000]  [<4014e5c4>] forget_original_parent+0xac/0xd0
      [    4.660000]  [<4014e5fe>] exit_notify+0x16/0xf2
      [    4.660000]  [<4014e8a5>] do_exit+0x1cb/0x225
      [    4.660000]  [<4015c72b>] ? kthread+0x0/0x69
      [    4.660000]  [<4011f61d>] kernel_thread_helper+0xd/0x10
      [    4.660000] ---[ end trace a7919e7f17c0a725 ]---
      [    4.660164] .. no entries found ..FAILED!
      
      During the selftest of irqsoff tracer, we do that:
      
      	/* disable interrupts for a bit */
      	local_irq_disable();
      	udelay(100);
      	local_irq_enable();
      	/* stop the tracing. */
      	tracing_stop();
      	/* check both trace buffers */
      	ret = trace_test_buffer(tr, NULL);
      
      If a callsite performs a new max delay with irqs off just after
      tracing_stop, update_max_tr_single() -> ring_buffer_swap_cpu()
      will be called with the buffers disabled by tracing_stop(), hence
      the warning, then ring_buffer_swap_cpu() return -EAGAIN and
      update_max_tr_single() complains.
      
      Fix it by also stopping the tracer before stopping the tracing globally.
      A similar situation can happen with preemptoff and preemptirqsoff tracers
      where we apply the same fix.
      Reported-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      LKML-Reference: <1237325938-5240-1-git-send-email-fweisbec@gmail.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      49036200
    • Carsten Emde's avatar
      tracing: fix command line to pid reverse map · a635cf04
      Carsten Emde authored
      
      
      Impact: fix command line to pid mapping
      
      map_cmdline_to_pid[] is checked in trace_save_cmdline(), but never
      updated. This results in stale pid to command line mappings and the
      tracer output will associate the wrong comm string.
      Signed-off-by: default avatarCarsten Emde <Carsten.Emde@osadl.org>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: Steven Rostedt <srostedt@redhat.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <new-submission>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      a635cf04
    • Thomas Gleixner's avatar
      tracing: fix trace_find_cmdline() · 50d88758
      Thomas Gleixner authored
      
      
      Impact: prevent stale command line output
      
      In case there is no valid command line mapping for a pid
      trace_find_cmdline() returns without updating the comm buffer. The
      trace dump keeps the previous entry which results in confusing trace
      output:
      
           <idle>-0     [000]   280.702056 ....
           <idle>-23456 [000]   280.702080 ....
      
      Update the comm buffer with "<...>" when no mapping is found.
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: Steven Rostedt <srostedt@redhat.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <new-submission>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      50d88758
    • Thomas Gleixner's avatar
      tracing: replace the crude (unsigned) -1 hackery · 2c7eea4c
      Thomas Gleixner authored
      
      
      Impact: cleanup
      
      The command line recorder uses (unsigned) -1 to mark non mapped
      entries in the pid to command line maps. The validity check is
      completely unintuitive: idx >= SAVED_CMDLINES
      
      There is no need for such casting games. Use a constant to mark
      unmapped entries and check for that constant to make the code readable
      and understandable.
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: Steven Rostedt <srostedt@redhat.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <new-submission>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      2c7eea4c
    • Thomas Gleixner's avatar
      tracing: stop command line recording when tracing is disabled · 18aecd36
      Thomas Gleixner authored
      
      
      Impact: prevent overwrite of command line entries
      
      When the tracer is stopped the command line recording continues to
      record. The check for tracing_is_on() is not sufficient here as the
      ringbuffer status is not affected by setting
      debug/tracing/tracing_enabled to 0. On a non idle system this can
      result in the loss of the command line information for the stopped
      trace, which makes the trace harder to read and analyse.
      
      Check tracer_enabled to allow further recording.
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: Steven Rostedt <srostedt@redhat.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <new-submission>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      18aecd36
    • Steven Rostedt's avatar
      tracing: make power tracer start/stop methods lighter weight · 62524d55
      Steven Rostedt authored
      
      
      The start/stop methods of a tracer should be able to be executed
      in all contexts. This patch converts the power tracer to do so.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      62524d55
    • Steven Rostedt's avatar
      tracing: make sched_switch stop/start light weight · 5fec6ddc
      Steven Rostedt authored
      
      
      The stopping and starting of a tracer should be light weight and
      be able to be called in all contexts. The sched_switch grabbed
      mutexes in the start/stop functions. This patch changes it to a
      simple variable, on/off.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      5fec6ddc
    • Steven Rostedt's avatar
      tracing: add global-clock option to provide cross CPU clock to traces · af4617bd
      Steven Rostedt authored
      
      
      Impact: feature to allow better serialized clock
      
      This patch adds an option called "global-clock" that will allow
      the tracer to switch to a slower but more accurate (across CPUs)
      clock.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      af4617bd
    • Steven Rostedt's avatar
      ring-buffer: add api to allow a tracer to change clock source · 37886f6a
      Steven Rostedt authored
      
      
      This patch adds a new function called ring_buffer_set_clock that
      allows a tracer to assign its own clock source to the buffer.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      37886f6a
  8. 17 Mar, 2009 4 commits
    • Tom Zanussi's avatar
      tracing: fix leak in event_format_read() · c269fc8c
      Tom Zanussi authored
      
      
      Impact: fix memory leak
      
      If event_format_read() exits early due to nonzero ppos, the
      previous kmalloc doesn't get freed - might as well do the
      check before the kmalloc and avoid the problem.
      Signed-off-by: default avatarTom Zanussi <tzanussi@gmail.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: =?ISO-8859-1?Q?Fr=E9d=E9ric?= Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <1237270859.8033.141.camel@charm-linux>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      c269fc8c
    • Steven Rostedt's avatar
      tracing: stop comm recording on tracing off · 6adaad14
      Steven Rostedt authored
      
      
      Impact: fix for losing comms in trace
      
      The command lines of tasks are cached at sched switch to not need
      to record them at every trace point.  Disabling the tracing on stops
      the recording of traces, but does not stop the caching of command lines.
      When the tracing is off the cache may overflow and cause the tracing
      to show incorrect tasks matching the PIDs.
      
      This patch disables prevents updates to the comm cache when the ring buffer
      is off.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      6adaad14
    • Steven Rostedt's avatar
      tracing: protect reader of cmdline output · 4ca53085
      Steven Rostedt authored
      
      
      Impact: fix to one cause of incorrect comm outputs in trace
      
      The spinlock only protected the creation of a comm <=> pid pair.
      But it was possible that a reader could look up a pid, and get the
      wrong comm because it had no locking.
      
      This also required changing trace_find_cmdline to copy the comm cache
      and not just send back a pointer to it.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      4ca53085
    • Frederic Weisbecker's avatar
      tracing/ftrace: fix the check on nopped sites · 03303549
      Frederic Weisbecker authored
      Impact: fix a dynamic tracing failure
      
      Recently, the function and function graph tracers failed to use dynamic
      tracing after the following commit:
      
      fa9d13cf
      
      
      (ftrace: don't try to __ftrace_replace_code on !FTRACE_FL_CONVERTED rec)
      
      The patch is right except a mistake on the check for the FTRACE_FL_CONVERTED
      flag. The code patching is aborted in case of successfully nopped sites.
      What we want is the opposite: ignore the callsites that haven't been nopped.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      03303549
  9. 16 Mar, 2009 7 commits
    • Frederic Weisbecker's avatar
      tracing/core: fix early free of cpumasks · 2fc1dfbe
      Frederic Weisbecker authored
      
      
      Impact: fix crashes when tracing cpumasks
      
      While ring-buffer allocation, the cpumasks are allocated too,
      including the tracing cpumask and the per-cpu file mask handler.
      But these cpumasks are freed accidentally just after.
      Fix it.
      Reported-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <1237164303-11476-1-git-send-email-fweisbec@gmail.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      2fc1dfbe
    • Frederic Weisbecker's avatar
      tracing/ftrace: fix double calls to tracing_start() · ac1d52d0
      Frederic Weisbecker authored
      
      
      Impact: fix a warning during preemptirqsoff selftests
      
      When the preemptirqsoff selftest fails, we see the following
      warning:
      
      [    6.050000] Testing tracer preemptirqsoff: .. no entries found ..
      ------------[ cut here ]------------
      [    6.060000] WARNING: at kernel/trace/trace.c:688 tracing_start+0x67/0xd3()
      [    6.060000] Modules linked in:
      [    6.060000] Pid: 1, comm: swapper Tainted: G
      [    6.060000] Call Trace:
      [    6.060000]  [<ffffffff802460ff>] warn_slowpath+0xb1/0x100
      [    6.060000]  [<ffffffff802a8f5b>] ? trace_preempt_on+0x35/0x4b
      [    6.060000]  [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3
      [    6.060000]  [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3
      [    6.060000]  [<ffffffff80271e0b>] ? __lock_acquired+0xe6/0x1f2
      [    6.060000]  [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3
      [    6.060000]  [<ffffffff802a3831>] tracing_start+0x67/0xd3
      [    6.060000]  [<ffffffff802a8ace>] ? irqsoff_tracer_reset+0x2d/0x57
      [    6.060000]  [<ffffffff802a4d1c>] trace_selftest_startup_preemptirqsoff+0x1c8/0x1f1
      [    6.060000]  [<ffffffff802a4798>] register_tracer+0x12f/0x241
      [    6.060000]  [<ffffffff810250d0>] ? init_irqsoff_tracer+0x0/0x53
      [    6.060000]  [<ffffffff8102510b>] init_irqsoff_tracer+0x3b/0x53
      
      This is because in fail case, the preemptirqsoff tracer selftest calls twice
      the tracing_start() function:
      
      int
      trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr)
      {
              if (!ret && !count) {
                      printk(KERN_CONT ".. no entries found ..");
                      ret = -1;
                      tracing_start(); <-----
                      goto out;
              }
              [...]
      out:
              trace->reset(tr);
              tracing_start(); <------
              tracing_max_latency = save_max;
      
              return ret;
      }
      
      Since it is well handled in the out path, we don't need the conditional one.
      Reported-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <1237159961-7447-1-git-send-email-fweisbec@gmail.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      ac1d52d0
    • Frederic Weisbecker's avatar
      tracing/core: fix missing mutex unlock on tracing_set_tracer() · 59f586db
      Frederic Weisbecker authored
      
      
      Impact: fix possible locking imbalance
      
      In case of ring buffer resize failure, tracing_set_tracer forgot to
      release trace_types_lock. Fix it.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <1237151439-6755-5-git-send-email-fweisbec@gmail.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      59f586db
    • Frederic Weisbecker's avatar
      tracing/syscalls: select kallsysms · 0ea1c415
      Frederic Weisbecker authored
      
      
      Syscall tracing must select kallsysms.
      
      The arch code builds a table to find the syscall metadata by syscall
      number. It needs the syscalls names resolution from the symbol table
      to know which name found on the syscalls metadatas match a function
      pointer from the arch sys_call_table.
      Reported-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Reported-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <1237151439-6755-4-git-send-email-fweisbec@gmail.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      0ea1c415
    • Frederic Weisbecker's avatar
      tracing/syscalls: protect thread flag toggling from races · 5be71b61
      Frederic Weisbecker authored
      
      
      Impact: fix syscall tracer enable/disable race
      
      The current thread flag toggling is racy as shown in the following
      scenario:
      
      - task A is the last user of syscall tracing, it releases the
        TIF_SYSCALL_FTRACE on each tasks
      
      - at the same time task B start syscall tracing. refcount == 0 so
        it sets up TIF_SYSCALL_FTRACE on each tasks.
      
      The effect of the mixup is unpredictable.
      So this fix adds a mutex on {start,stop}_syscall_tracing().
      Reported-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Reported-by: default avatarIngo Molnar <mingo@elte.hu>
      LKML-Reference: <1237151439-6755-3-git-send-email-fweisbec@gmail.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      5be71b61
    • Frederic Weisbecker's avatar
      tracing/syscalls: various cleanups · 64044345
      Frederic Weisbecker authored
      
      
      Impact: cleanup
      
      - Drop unused cpu variable
      - Fix some errors on comments
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <1237151439-6755-2-git-send-email-fweisbec@gmail.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      64044345
    • Frederic Weisbecker's avatar
      tracing/syscalls: fix missing release of tracing · ac99c58c
      Frederic Weisbecker authored
      
      
      Impact: fix 'stuck' syscall tracer
      
      The syscall tracer uses a refcounter to enable several users
      simultaneously.
      
      But the refcounter did not behave correctly and always restored
      its value to 0 after calling start_syscall_tracing(). Therefore,
      stop_syscall_tracing() couldn't release correctly the tasks from
      tracing.
      
      Also the tracer forgot to reset the buffer when it is released.
      
      Drop the pointless refcount decrement on start_syscall_tracing()
      and reset the buffer when we release the tracer.
      
      This fixes two reported issue:
      
      - when we switch from syscall tracer to another tracer, syscall
        tracing continued.
      
      - incorrect use of the refcount.
      Reported-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Reported-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <1237151439-6755-1-git-send-email-fweisbec@gmail.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      ac99c58c
  10. 13 Mar, 2009 2 commits
    • Frederic Weisbecker's avatar
      tracing/syscalls: core infrastructure for syscalls tracing, enhancements · bed1ffca
      Frederic Weisbecker authored
      
      
      Impact: new feature
      
      This adds the generic support for syscalls tracing. This is
      currently exploited through a devoted tracer but other tracing
      engines can use it. (They just have to play with
      {start,stop}_ftrace_syscalls() and use the display callbacks
      unless they want to override them.)
      
      The syscalls prototypes definitions are abused here to steal
      some metadata informations:
      
      - syscall name, param types, param names, number of params
      
      The syscall addr is not directly saved during this definition
      because we don't know if its prototype is available in the
      namespace. But we don't really need it. The arch has just to
      build a function able to resolve the syscall number to its
      metadata struct.
      
      The current tracer prints the syscall names, parameters names
      and values (and their types optionally). Currently the value is
      a raw hex but higher level values diplaying is on my TODO list.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <1236955332-10133-2-git-send-email-fweisbec@gmail.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      bed1ffca
    • Lai Jiangshan's avatar
      ftrace: remove struct list_head from struct dyn_ftrace · e94142a6
      Lai Jiangshan authored
      
      
      Impact: save memory
      
      The struct dyn_ftrace table is very large, this patch will save
      about 50%.
      Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
      Cc: Steven Rostedt <srostedt@redhat.com>
      LKML-Reference: <49BA2C9F.8020009@cn.fujitsu.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      e94142a6