1. 23 Apr, 2009 2 commits
    • Steven Rostedt's avatar
      tracing: increase size of number of possible events · 89ec0dee
      Steven Rostedt authored
      
      
      With the new event tracing registration, we must increase the number
      of events that can be registered. Currently the type field is only
      one byte, which leaves us only 256 possible events.
      
      Since we do not save the CPU number in the tracer anymore (it is determined
      by the per cpu ring buffer that is used) we have an extra byte to use.
      
      This patch increases the size of type from 1 byte (256 events) to
      2 bytes (65,536 events).
      
      It also adds a WARN_ON_ONCE if we exceed that limit.
      
      [ Impact: allow more than 255 events ]
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      89ec0dee
    • Steven Rostedt's avatar
      tracing/wakeup: move access to wakeup_cpu into spinlock · 9be24414
      Steven Rostedt authored
      
      
      The code had the following outside the lock:
      
              if (next != wakeup_task)
                      return;
      
              pc = preempt_count();
      
              /* The task we are waiting for is waking up */
              data = wakeup_trace->data[wakeup_cpu];
      
      On initialization, wakeup_task is NULL and wakeup_cpu -1. This code
      is not under a lock. If wakeup_task is set on another CPU as that
      task is waking up, we can see the wakeup_task before wakeup_cpu is
      set. If we read wakeup_cpu while it is still -1 then we will have
      a bad data pointer.
      
      This patch moves the reading of wakeup_cpu within the protection of
      the spinlock used to protect the writing of wakeup_cpu and wakeup_task.
      
      [ Impact: remove possible race causing invalid pointer dereference ]
      Reported-by: default avatarManeesh Soni <maneesh@in.ibm.com>
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      9be24414
  2. 22 Apr, 2009 4 commits
    • Frederic Weisbecker's avatar
      tracing/events: protect __get_str() · 6a74aa40
      Frederic Weisbecker authored
      
      
      The __get_str() macro is used in a code part then its content should be
      protected with parenthesis.
      
      [ Impact: make macro definition more robust ]
      Reported-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      6a74aa40
    • Frederic Weisbecker's avatar
      tracing/lock: provide lock_acquired event support for dynamic size string · 7e7ca9a2
      Frederic Weisbecker authored
      
      
      Now that we can support the dynamic sized string, make the lock tracing
      able to use it, making it safe against modules removal and consuming
      the right amount of memory needed for each lock name
      
      Changes in v2:
      adapt to the __ending_string() updates and the opening_string() removal.
      
      [ Impact: protect lock tracer against module removal ]
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      7e7ca9a2
    • Frederic Weisbecker's avatar
      tracing/events: provide string with undefined size support · 9cbf1176
      Frederic Weisbecker authored
      
      
      This patch provides the support for dynamic size strings on
      event tracing.
      
      The key concept is to use a structure with an ending char array field of
      undefined size and use such ability to allocate the minimal size on the
      ring buffer to make one or more string entries fit inside, as opposite
      to a fixed length strings with upper bound.
      
      The strings themselves are represented using fields which have an offset
      value from the beginning of the entry.
      
      This patch provides three new macros:
      
      __string(item, src)
      
      This one declares a string to the structure inside TP_STRUCT__entry.
      You need to provide the name of the string field and the source that will
      be copied inside.
      This will also add the dynamic size of the string needed for the ring
      buffer entry allocation.
      A stack allocated structure is used to temporarily store the offset
      of each strings, avoiding double calls to strlen() on each event
      insertion.
      
      __get_str(field)
      
      This one will give you a pointer to the string you have created. This
      is an abstract helper to resolve the absolute address given the field
      name which is a relative address from the beginning of the trace_structure.
      
      __assign_str(dst, src)
      
      Use this macro to automatically perform the string copy from src to
      dst. src must be a variable to assign and dst is the name of a __string
      field.
      
      Example on how to use it:
      
      TRACE_EVENT(my_event,
      	TP_PROTO(char *src1, char *src2),
      
      	TP_ARGS(src1, src2),
      	TP_STRUCT__entry(
      		__string(str1, src1)
      		__string(str2, src2)
      	),
      	TP_fast_assign(
      		__assign_str(str1, src1);
      		__assign_str(str2, src2);
      	),
      	TP_printk("%s %s", __get_str(src1), __get_str(src2))
      )
      
      Of course you can mix-up any __field or __array inside this
      TRACE_EVENT. The position of the __string or __assign_str
      doesn't matter.
      
      Changes in v2:
      
      Address the suggestion of Steven Rostedt: drop the opening_string() macro
      and redefine __ending_string() to get the size of the string to be copied
      instead of overwritting the whole ring buffer allocation.
      
      Changes in v3:
      
      Address other suggestions of Steven Rostedt and Peter Zijlstra with
      some changes: drop the __ending_string and the need to have only one
      string field.
      Use offsets instead of absolute addresses.
      
      [ Impact: allow more compact memory usage for string tracing ]
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Li Zefan <lizf@cn.fujitsu.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      9cbf1176
    • Li Zefan's avatar
      tracing/events: make struct trace_entry->type to be int type · 7a4f453b
      Li Zefan authored
      
      
      struct trace_entry->type is unsigned char, while trace event's id is
      int type, thus for a event with id >= 256, it's entry->type is cast
      to (id % 256), and then we can't see the trace output of this event.
      
       # insmod trace-events-sample.ko
       # echo foo_bar > /mnt/tracing/set_event
       # cat /debug/tracing/events/trace-events-sample/foo_bar/id
       256
       # cat /mnt/tracing/trace_pipe
                 <...>-3548  [001]   215.091142: Unknown type 0
                 <...>-3548  [001]   216.089207: Unknown type 0
                 <...>-3548  [001]   217.087271: Unknown type 0
                 <...>-3548  [001]   218.085332: Unknown type 0
      
      [ Impact: fix output for trace events with id >= 256 ]
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      Acked-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Tom Zanussi <tzanussi@gmail.com>
      LKML-Reference: <49EEDB0E.5070207@cn.fujitsu.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      7a4f453b
  3. 21 Apr, 2009 3 commits
    • Steven Rostedt's avatar
      ring-buffer: only warn on wrap if buffer is bigger than two pages · 3554228d
      Steven Rostedt authored
      
      
      On boot up, to save memory, ftrace allocates the minimum buffer
      which is two pages. Ftrace also goes through a series of tests
      (when configured) on boot up. These tests can fill up a page within
      a single interrupt.
      
      The ring buffer also has a WARN_ON when it detects that the buffer was
      completely filled within a single commit (other commits are allowed to
      be nested).
      
      Combine the small buffer on start up, with the tests that can fill more
      than a single page within an interrupt, this can trigger the WARN_ON.
      
      This patch makes the WARN_ON only happen when the ring buffer consists
      of more than two pages.
      
      [ Impact: prevent false WARN_ON in ftrace startup tests ]
      Reported-by: default avatarIngo Molnar <mingo@elte.hu>
      LKML-Reference: <20090421094616.GA14561@elte.hu>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      3554228d
    • Li Zefan's avatar
      tracing/filters: allow user-input to be integer-like string · f66578a7
      Li Zefan authored
      
      
      Suppose we would like to trace all tasks named '123', but this
      will fail:
      
       # echo 'parent_comm == 123' > events/sched/sched_process_fork/filter
       bash: echo: write error: Invalid argument
      
      Don't guess the type of the filter pred in filter_parse(), but instead
      we check it in __filter_add_pred().
      
      [ Impact: extend allowed filter field string values ]
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      Cc: Tom Zanussi <tzanussi@gmail.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <49ED8DEB.6000700@cn.fujitsu.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      f66578a7
    • Li Zefan's avatar
      tracing/filters: don't remove old filters when failed to write subsys->filter · e8082f3f
      Li Zefan authored
      
      
      If writing subsys->filter returns EINVAL or ENOSPC, the original
      filters in subsys/ and subsys/events/ will be removed. This is
      definitely wrong.
      
      [ Impact: fix filter setting semantics on error condition ]
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      Cc: Tom Zanussi <tzanussi@gmail.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <49ED8DD2.2070700@cn.fujitsu.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      e8082f3f
  4. 20 Apr, 2009 10 commits
    • Steven Rostedt's avatar
      tracing: use nowakeup version of commit for function event trace tests · cb4764a6
      Steven Rostedt authored
      
      
      The startup tests for the event tracer also runs with the function
      tracer enabled. The "wakeup" version of the trace commit was used
      which can grab spinlocks. If a task was preempted by an NMI
      that called a function being traced, it could deadlock due to the
      function tracer trying to grab the same lock.
      
      Thanks to Frederic Weisbecker for pointing out where the bug was.
      Reported-by: default avatarIngo Molnar <mingo@elte.hu>
      Reported-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      cb4764a6
    • Steven Rostedt's avatar
      tracing: use recursive counter over irq level · aa18efb2
      Steven Rostedt authored
      
      
      Althought using the irq level (hardirq_count, softirq_count and in_nmi)
      was nice to detect bad recursion right away, but since the counters are
      not atomically updated with respect to the interrupts, the function tracer
      might trigger the test from an interrupt handler before the hardirq_count
      is updated. This will trigger a false warning.
      
      This patch converts the recursive detection to a simple counter.
      If the depth is greater than 16 then the recursive detection will trigger.
      16 is more than enough for any nested interrupts.
      
      [ Impact: fix false positive trace recursion detection ]
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      aa18efb2
    • Steven Rostedt's avatar
      tracing: remove recursive test from ring_buffer_event_discard · e395898e
      Steven Rostedt authored
      
      
      The ring_buffer_event_discard is not tied to ring_buffer_lock_reserve.
      It can be called inside or outside the reserve/commit. Even if it
      is called inside the reserve/commit the commit part must also be called.
      
      Only ring_buffer_discard_commit can be used as a replacement for
      ring_buffer_unlock_commit.
      
      This patch removes the trace_recursive_unlock from ring_buffer_event_discard
      since it would be the wrong place to do so.
      
      [Impact: prevent breakage in trace recursive testing ]
      
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      e395898e
    • Steven Rostedt's avatar
      tracing: fix recursive test level calculation · 17487bfe
      Steven Rostedt authored
      
      
      The recursive tests to detect same level recursion in the ring buffers
      did not account for the hard/softirq_counts to be shifted. Thus the
      numbers could be larger than then mask to be tested.
      
      This patch includes the shift for the calculation of the irq depth.
      
      [ Impact: stop false positives in trace recursion detection ]
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      17487bfe
    • Steven Rostedt's avatar
      tracing: remove dangling semicolon · 23de29de
      Steven Rostedt authored
      
      
      Due to a cut and paste error, the trace_seq_putc had a semicolon
      after the prototype but before the stub function when tracing is
      disabled.
      
      [Impact: fix compile error ]
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      23de29de
    • Steven Rostedt's avatar
      tracing/events: call the correct event trace selftest init function · 28d20e2d
      Steven Rostedt authored
      
      
      The late_initcall calls a helper function instead of the proper
      init event selftest function.
      
      This update may have been lost due to conflicting merges.
      
      [ Impact: fix compiler warning and call extended event trace self tests ]
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      28d20e2d
    • Steven Rostedt's avatar
      tracing: rename EVENT_TRACER config to ENABLE_EVENT_TRACING · a7abe97f
      Steven Rostedt authored
      
      
      Currently we have two configs: EVENT_TRACING and EVENT_TRACER.
      All tracers enable EVENT_TRACING. The EVENT_TRACER is only a
      convenience to enable the EVENT_TRACING when no other tracers
      are enabled.
      
      The names EVENT_TRACER and EVENT_TRACING are too similar and confusing.
      This patch renames EVENT_TRACER to ENABLE_EVENT_TRACING to be more
      appropriate to what it actually does, as well as add a comment in
      the help menu to explain the option's purpose.
      
      [ Impact: rename config option to reduce confusion ]
      Reported-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      a7abe97f
    • Steven Rostedt's avatar
      tracing: create menuconfig for tracing infrastructure · 4ed9f071
      Steven Rostedt authored
      
      
      During testing we often use randconfig to test various kernels.
      The current configuration set up does not give an easy way to disable
      all tracing with a single config. The case where randconfig would
      test all tracing disabled is very unlikely.
      
      This patch adds a config option to enable or disable all tracing.
      It is hooked into the tracing menu just like other submenus are done.
      
      [ Impact: allow randconfig to easily produce all traces disabled ]
      Reported-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      4ed9f071
    • Steven Rostedt's avatar
      tracing: change branch profiling to a choice selection · 9ae5b879
      Steven Rostedt authored
      
      
      This patch makes the branch profiling into a choice selection:
      
        None               - no branch profiling
        likely/unlikely    - only profile likely/unlikely branches
        all                - profile all branches
      
      The all profiler will also enable the likely/unlikely branches.
      
      This does not change the way the profiler works or the dependencies
      between the profilers.
      
      What this patch does, is keep the branch profiling from being selected
      by an allyesconfig make. The branch profiler is very intrusive and
      it is known to break various architecture builds when selected as an
      allyesconfig.
      
      [ Impact: prevent branch profiler from being selected in allyesconfig ]
      Reported-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Reported-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Reported-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
      Reported-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      9ae5b879
    • Frederic Weisbecker's avatar
      tracing/ring-buffer: Add unlock recursion protection on discard · f3b9aae1
      Frederic Weisbecker authored
      
      
      The pair of helpers trace_recursive_lock() and trace_recursive_unlock()
      have been introduced recently to provide generic tracing recursion
      protection.
      
      They are used in a symetric way:
      
       - trace_recursive_lock() on buffer reserve
       - trace_recursive_unlock() on buffer commit
      
      However sometimes, we don't commit but discard on entry
      to the buffer, ie: in case of filter checking.
      
      Then we must also unlock the recursion protection on discard time,
      otherwise the tracing gets definitely deactivated and a warning
      is raised spuriously, such as:
      
      111.119821] ------------[ cut here ]------------
      [  111.119829] WARNING: at kernel/trace/ring_buffer.c:1498 ring_buffer_lock_reserve+0x1b7/0x1d0()
      [  111.119835] Hardware name: AMILO Li 2727
      [  111.119839] Modules linked in:
      [  111.119846] Pid: 5731, comm: Xorg Tainted: G        W  2.6.30-rc1 #69
      [  111.119851] Call Trace:
      [  111.119863]  [<ffffffff8025ce68>] warn_slowpath+0xd8/0x130
      [  111.119873]  [<ffffffff8028a30f>] ? __lock_acquire+0x19f/0x1ae0
      [  111.119882]  [<ffffffff8028a30f>] ? __lock_acquire+0x19f/0x1ae0
      [  111.119891]  [<ffffffff802199b0>] ? native_sched_clock+0x20/0x70
      [  111.119899]  [<ffffffff80286dee>] ? put_lock_stats+0xe/0x30
      [  111.119906]  [<ffffffff80286eb8>] ? lock_release_holdtime+0xa8/0x150
      [  111.119913]  [<ffffffff802c8ae7>] ring_buffer_lock_reserve+0x1b7/0x1d0
      [  111.119921]  [<ffffffff802cd110>] trace_buffer_lock_reserve+0x30/0x70
      [  111.119930]  [<ffffffff802ce000>] trace_current_buffer_lock_reserve+0x20/0x30
      [  111.119939]  [<ffffffff802474e8>] ftrace_raw_event_sched_switch+0x58/0x100
      [  111.119948]  [<ffffffff808103b7>] __schedule+0x3a7/0x4cd
      [  111.119957]  [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b
      [  111.119964]  [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b
      [  111.119971]  [<ffffffff80810c08>] schedule+0x18/0x40
      [  111.119977]  [<ffffffff80810e09>] preempt_schedule+0x39/0x60
      [  111.119985]  [<ffffffff80813bd3>] _read_unlock+0x53/0x60
      [  111.119993]  [<ffffffff807259d2>] sock_def_readable+0x72/0x80
      [  111.120002]  [<ffffffff807ad5ed>] unix_stream_sendmsg+0x24d/0x3d0
      [  111.120011]  [<ffffffff807219a3>] sock_aio_write+0x143/0x160
      [  111.120019]  [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b
      [  111.120026]  [<ffffffff80721860>] ? sock_aio_write+0x0/0x160
      [  111.120033]  [<ffffffff80721860>] ? sock_aio_write+0x0/0x160
      [  111.120042]  [<ffffffff8031c283>] do_sync_readv_writev+0xf3/0x140
      [  111.120049]  [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b
      [  111.120057]  [<ffffffff80276ff0>] ? autoremove_wake_function+0x0/0x40
      [  111.120067]  [<ffffffff8045d489>] ? cap_file_permission+0x9/0x10
      [  111.120074]  [<ffffffff8045c1e6>] ? security_file_permission+0x16/0x20
      [  111.120082]  [<ffffffff8031cab4>] do_readv_writev+0xd4/0x1f0
      [  111.120089]  [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b
      [  111.120097]  [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b
      [  111.120105]  [<ffffffff8031cc18>] vfs_writev+0x48/0x70
      [  111.120111]  [<ffffffff8031cd65>] sys_writev+0x55/0xc0
      [  111.120119]  [<ffffffff80211e32>] system_call_fastpath+0x16/0x1b
      [  111.120125] ---[ end trace 15605f4e98d5ccb5 ]---
      
      [ Impact: fix spurious warning triggering tracing shutdown ]
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      f3b9aae1
  5. 19 Apr, 2009 1 commit
    • Frederic Weisbecker's avatar
      tracing/core: Add current context on tracing recursion warning · e057a5e5
      Frederic Weisbecker authored
      
      
      In case of tracing recursion detection, we only get the stacktrace.
      But the current context may be very useful to debug the issue.
      
      This patch adds the softirq/hardirq/nmi context with the warning
      using lockdep context display to have a familiar output.
      
      v2: Use printk_once()
      v3: drop {hardirq,softirq}_context which depend on lockdep,
          only keep what is part of current->trace_recursion,
          sufficient to debug the warning source.
      
      [ Impact: print context necessary to debug recursion ]
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      e057a5e5
  6. 18 Apr, 2009 1 commit
  7. 17 Apr, 2009 13 commits
    • Steven Rostedt's avatar
      tracing: protect trace_printk from recursion · 3189cdb3
      Steven Rostedt authored
      
      
      trace_printk can be called from any context, including NMIs.
      If this happens, then we must test for for recursion before
      grabbing any spinlocks.
      
      This patch prevents trace_printk from being called recursively.
      
      [ Impact: prevent hard lockup in lockdep event tracer ]
      
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      3189cdb3
    • Steven Rostedt's avatar
      tracing: add same level recursion detection · 261842b7
      Steven Rostedt authored
      
      
      The tracing infrastructure allows for recursion. That is, an interrupt
      may interrupt the act of tracing an event, and that interrupt may very well
      perform its own trace. This is a recursive trace, and is fine to do.
      
      The problem arises when there is a bug, and the utility doing the trace
      calls something that recurses back into the tracer. This recursion is not
      caused by an external event like an interrupt, but by code that is not
      expected to recurse. The result could be a lockup.
      
      This patch adds a bitmask to the task structure that keeps track
      of the trace recursion. To find the interrupt depth, the following
      algorithm is used:
      
        level = hardirq_count() + softirq_count() + in_nmi;
      
      Here, level will be the depth of interrutps and softirqs, and even handles
      the nmi. Then the corresponding bit is set in the recursion bitmask.
      If the bit was already set, we know we had a recursion at the same level
      and we warn about it and fail the writing to the buffer.
      
      After the data has been committed to the buffer, we clear the bit.
      No atomics are needed. The only races are with interrupts and they reset
      the bitmask before returning anywy.
      
      [ Impact: detect same irq level trace recursion ]
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      261842b7
    • Steven Rostedt's avatar
      tracing: add EXPORT_SYMBOL_GPL for trace commits · 12acd473
      Steven Rostedt authored
      
      
      Not all the necessary symbols were exported to allow for tracing
      by modules. This patch adds them in.
      
      [ Impact: allow modules to commit data to the ring buffer ]
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      12acd473
    • Steven Rostedt's avatar
      tracing/events: enable code with EVENT_TRACING not EVENT_TRACER · b0afdc12
      Steven Rostedt authored
      
      
      The CONFIG_EVENT_TRACER is the way to turn on event tracing when no
      other tracing has been configured. All code to get enabled should
      depend on CONFIG_EVENT_TRACING. That is what is enabled when TRACING
      (or CONFIG_EVENT_TRACER) is selected.
      
      This patch enables the include/trace/ftrace.h file when
      CONFIG_EVENT_TRACING is enabled.
      
      [ Impact: fix warning in event tracer selftest ]
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      b0afdc12
    • Tom Zanussi's avatar
      tracing/filters: add filter_mutex to protect filter predicates · ac1adc55
      Tom Zanussi authored
      
      
      This patch adds a filter_mutex to prevent the filter predicates from
      being accessed concurrently by various external functions.
      
      It's based on a previous patch by Li Zefan:
              "[PATCH 7/7] tracing/filters: make filter preds RCU safe"
      
      v2 changes:
      
      - fixed wrong value returned in a add_subsystem_pred() failure case
        noticed by Li Zefan.
      
      [ Impact: fix trace filter corruption/crashes on parallel access ]
      Signed-off-by: default avatarTom Zanussi <tzanussi@gmail.com>
      Reviewed-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      Tested-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: paulmck@linux.vnet.ibm.com
      LKML-Reference: <1239946028.6639.13.camel@tropicana>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      ac1adc55
    • Zhaolei's avatar
      tracing: Remove include/trace/kmem_event_types.h · 46de405f
      Zhaolei authored
      
      
      kmem_event_types.h is no longer necessary since tracepoint definitions
      are put into include/trace/events/kmem.h
      
      [ Impact: remove now-unused file. ]
      Signed-off-by: default avatarZhao Lei <zhaolei@cn.fujitsu.com>
      Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Tom Zanussi <tzanussi@gmail.com>
      LKML-Reference: <49E7EF37.20802057
      
      @cn.fujitsu.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      46de405f
    • Li Zefan's avatar
      tracing: fix file mode of trace and README · 339ae5d3
      Li Zefan authored
      
      
      trace is read-write and README is read-only.
      
      [ Impact: fix /debug/tracing/ file permissions. ]
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      Acked-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      LKML-Reference: <49E7EAB6.4070605@cn.fujitsu.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      339ae5d3
    • Jeremy Fitzhardinge's avatar
      tracing: avoid warnings from zero-arg tracepoints · 76aa8111
      Jeremy Fitzhardinge authored
      
      
      Tracepoints with no arguments can issue two warnings:
      
      	"field" defined by not used
      	"ret" is uninitialized in this function
      
      Mark field as being OK to leave unused, and initialize ret.
      
      [ Impact: fix false positive compiler warnings. ]
      Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Cc: mathieu.desnoyers@polymtl.ca
      LKML-Reference: <1239950139-1119-5-git-send-email-jeremy@goop.org>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      76aa8111
    • Steven Rostedt's avatar
      tracing/events: perform function tracing in event selftests · 9ea21c1e
      Steven Rostedt authored
      
      
      We can find some bugs in the trace events if we stress the writes as well.
      The function tracer is a good way to stress the events.
      
      [ Impact: extend scope of event tracer self-tests ]
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <20090416161746.604786131@goodmis.org>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      9ea21c1e
    • Avadh Patel's avatar
      tracing: add saved_cmdlines file to show cached task comms · 69abe6a5
      Avadh Patel authored
      
      
      Export the cached task comms to userspace. This allows user apps to translate
      the pids from a trace into their respective task command lines.
      
      [ Impact: let userspace apps reading binary buffer know comm's of pids ]
      Signed-off-by: default avatarAvadh Patel <avadh4all@gmail.com>
      [ added error checking and use of buf pointer to index file_buf ]
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      69abe6a5
    • Steven Rostedt's avatar
      tracing/events/ring-buffer: expose format of ring buffer headers to users · d1b182a8
      Steven Rostedt authored
      
      
      Currently, every thing needed to read the binary output from the
      ring buffers is available, with the exception of the way the ring
      buffers handles itself internally.
      
      This patch creates two special files in the debugfs/tracing/events
      directory:
      
       # cat /debug/tracing/events/header_page
              field: u64 timestamp;   offset:0;       size:8;
              field: local_t commit;  offset:8;       size:8;
              field: char data;       offset:16;      size:4080;
      
       # cat /debug/tracing/events/header_event
              type        :    2 bits
              len         :    3 bits
              time_delta  :   27 bits
              array       :   32 bits
      
              padding     : type == 0
              time_extend : type == 1
              data        : type == 3
      
      This is to allow a userspace app to see if the ring buffer format changes
      or not.
      
      [ Impact: allow userspace apps to know of ringbuffer format changes ]
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      d1b182a8
    • Steven Rostedt's avatar
      tracing/events: add startup tests for events · e6187007
      Steven Rostedt authored
      
      
      As events start to become popular, and the new way to add tracing
      infrastructure into ftrace, it is important to catch any problems
      that might happen with a mistake in the TRACE_EVENT macro.
      
      This patch introduces a startup self test on the registered trace
      events. Note, it can only do a generic test, any type of testing that
      needs more involement is needed to be implemented by the tracepoint
      creators.
      
      The test goes down one by one enabling a trace point and running
      some random tasks (random in the sense that I just made them up).
      Those tasks are creating threads, grabbing mutexes and spinlocks
      and using workqueues.
      
      After testing each event individually, it does the same test after
      enabling each system of trace points. Like sched, irq, lockdep.
      
      Then finally it enables all tracepoints and performs the tasks again.
      The output to the console on bootup will look like this when everything
      works:
      
      Running tests on trace events:
      Testing event kfree_skb: OK
      Testing event kmalloc: OK
      Testing event kmem_cache_alloc: OK
      Testing event kmalloc_node: OK
      Testing event kmem_cache_alloc_node: OK
      Testing event kfree: OK
      Testing event kmem_cache_free: OK
      Testing event irq_handler_exit: OK
      Testing event irq_handler_entry: OK
      Testing event softirq_entry: OK
      Testing event softirq_exit: OK
      Testing event lock_acquire: OK
      Testing event lock_release: OK
      Testing event sched_kthread_stop: OK
      Testing event sched_kthread_stop_ret: OK
      Testing event sched_wait_task: OK
      Testing event sched_wakeup: OK
      Testing event sched_wakeup_new: OK
      Testing event sched_switch: OK
      Testing event sched_migrate_task: OK
      Testing event sched_process_free: OK
      Testing event sched_process_exit: OK
      Testing event sched_process_wait: OK
      Testing event sched_process_fork: OK
      Testing event sched_signal_send: OK
      Running tests on trace event systems:
      Testing event system skb: OK
      Testing event system kmem: OK
      Testing event system irq: OK
      Testing event system lockdep: OK
      Testing event system sched: OK
      Running tests on all trace events:
      Testing all events: OK
      
      [ folded in:
      
        tracing: add #include <linux/delay.h> to fix build failure in test_work()
      
        This build failure occured on a few rare configs:
      
         kernel/trace/trace_events.c: In function ‘test_work’:
         kernel/trace/trace_events.c:975: error: implicit declaration of function ‘udelay’
         kernel/trace/trace_events.c:980: error: implicit declaration of function ‘msleep’
      
        delay.h is included in way too many other headers, hiding cases
        where new usage is added without header inclusion.
      
        [ Impact: build fix ]
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      ]
      
      [ Impact: add event tracer self-tests ]
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      e6187007
    • Steven Rostedt's avatar
      ftrace: use module notifier for function tracer · 93eb677d
      Steven Rostedt authored
      
      
      The hooks in the module code for the function tracer must be called
      before any of that module code runs. The function tracer hooks
      modify the module (replacing calls to mcount to nops). If the code
      is executed while the change occurs, then the CPU can take a GPF.
      
      To handle the above with a bit of paranoia, I originally implemented
      the hooks as calls directly from the module code.
      
      After examining the notifier calls, it looks as though the start up
      notify is called before any of the module's code is executed. This makes
      the use of the notify safe with ftrace.
      
      Only the startup notify is required to be "safe". The shutdown simply
      removes the entries from the ftrace function list, and does not modify
      any code.
      
      This change has another benefit. It removes a issue with a reverse dependency
      in the mutexes of ftrace_lock and module_mutex.
      
      [ Impact: fix lock dependency bug, cleanup ]
      
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      93eb677d
  8. 16 Apr, 2009 4 commits
    • Li Zefan's avatar
      blktrace: fix context-info when mixed-using blk tracer and trace events · f3948f88
      Li Zefan authored
      
      
      When current tracer is set to blk tracer, TRACE_ITER_CONTEXT_INFO is
      unset, but actually context-info is printed:
      
          pdflush-431   [000]   821.181576:   8,0    P   N [pdflush]
      
      And then if we enable TRACE_ITER_CONTEXT_INFO:
      
          # echo context-info > trace_options
      
      We'll see context-info printed twice. What's worse, when we use blk
      tracer and trace events at the same time, we'll see no context-info
      for trace events at all:
      
          jbd2_commit_logging: dev dm-0:8 transaction 333227
          jbd2_end_commit: dev dm-0:8 transaction 333227 head 332814
            rm-25433 [001]  9578.307485:   8,18   m   N cfq25433 slice expired t=0
            rm-25433 [001]  9578.307486:   8,18   m   N cfq25433 put_queue
      
      This patch adds blk_tracer->set_flags(), and context-info flag is unset
      only when we set the output to classic mode.
      
      Note after this patch, one should unset context-info explicitly if he
      wants to get binary output that can be parsed by blkparse:
      
          # echo nocontext-info > trace_options
          # echo bin > trace_options
          # echo blk > current_tracer
          # cat trace_pipe | blkparse -i -
      Reported-by: default avatarTheodore Ts'o <tytso@mit.edu>
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      Cc: Jens Axboe <jens.axboe@oracle.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      LKML-Reference: <49E54E60.50408@cn.fujitsu.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      f3948f88
    • Li Zefan's avatar
      blktrace: add trace/ to /sys/block/sda · 1d54ad6d
      Li Zefan authored
      
      
      Impact: allow ftrace-plugin blktrace to trace device-mapper devices
      
      To trace a single partition:
        # echo 1 > /sys/block/sda/sda1/enable
      
      To trace the whole sda instead:
        # echo 1 > /sys/block/sda/enable
      
      Thus we also fix an issue reported by Ted, that ftrace-plugin blktrace
      can't be used to trace device-mapper devices.
      
      Now:
      
        # echo 1 > /sys/block/dm-0/trace/enable
        echo: write error: No such device or address
        # mount -t ext4 /dev/dm-0 /mnt
        # echo 1 > /sys/block/dm-0/trace/enable
        # echo blk > /debug/tracing/current_tracer
      Reported-by: default avatarTheodore Tso <tytso@mit.edu>
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      Acked-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Shawn Du <duyuyang@gmail.com>
      Cc: Jens Axboe <jens.axboe@oracle.com>
      LKML-Reference: <49E42665.6020506@cn.fujitsu.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      1d54ad6d
    • Li Zefan's avatar
      blktrace: support per-partition tracing for ftrace plugin · 9908c309
      Li Zefan authored
      
      
      The previous patch adds support to trace a single partition for
      relay+ioctl blktrace, and this patch is for ftrace plugin blktrace:
      
        # echo 1 > /sys/block/sda/sda7/enable
        # cat start_lba
        102398373
        # cat end_lba
        102703545
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      Acked-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Shawn Du <duyuyang@gmail.com>
      Cc: Jens Axboe <jens.axboe@oracle.com>
      LKML-Reference: <49E42646.4060608@cn.fujitsu.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      9908c309
    • Shawn Du's avatar
      blktrace: support per-partition tracing · d0deef5b
      Shawn Du authored
      Though one can specify '-d /dev/sda1' when using blktrace, it still
      traces the whole sda.
      
      To support per-partition tracing, when we start tracing, we initialize
      bt->start_lba and bt->end_lba to the start and end sector of that
      partition.
      
      Note some actions are per device, thus we don't filter 0-sector events.
      
      The original patch and discussion can be found here:
      	http://marc.info/?l=linux-btrace&m=122949374214540&w=2
      
      Signed-off-by: default avatarShawn Du <duyuyang@gmail.com>
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      Acked-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Jens Axboe <jens.axboe@oracle.com>
      LKML-Reference: <49E42620.4050701@cn.fujitsu.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      d0deef5b
  9. 14 Apr, 2009 2 commits