Skip to content
Snippets Groups Projects
  1. Jul 21, 2010
    • Mike Frysinger's avatar
      tracing/documentation: Document dynamic ftracer internals · 9849ed4d
      Mike Frysinger authored
      
      Add more details to the dynamic function tracing design implementation.
      
      Signed-off-by: default avatarMike Frysinger <vapier@gentoo.org>
      LKML-Reference: <1279610015-10250-1-git-send-email-vapier@gentoo.org>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      9849ed4d
    • KOSAKI Motohiro's avatar
      tracing: Shrink max latency ringbuffer if unnecessary · ef710e10
      KOSAKI Motohiro authored
      
      Documentation/trace/ftrace.txt says
      
        buffer_size_kb:
      
              This sets or displays the number of kilobytes each CPU
              buffer can hold. The tracer buffers are the same size
              for each CPU. The displayed number is the size of the
              CPU buffer and not total size of all buffers. The
              trace buffers are allocated in pages (blocks of memory
              that the kernel uses for allocation, usually 4 KB in size).
              If the last page allocated has room for more bytes
              than requested, the rest of the page will be used,
              making the actual allocation bigger than requested.
              ( Note, the size may not be a multiple of the page size
                due to buffer management overhead. )
      
              This can only be updated when the current_tracer
              is set to "nop".
      
      But it's incorrect. currently total memory consumption is
      'buffer_size_kb x CPUs x 2'.
      
      Why two times difference is there? because ftrace implicitly allocate
      the buffer for max latency too.
      
      That makes sad result when admin want to use large buffer. (If admin
      want full logging and makes detail analysis). example, If admin
      have 24 CPUs machine and write 200MB to buffer_size_kb, the system
      consume ~10GB memory (200MB x 24 x 2). umm.. 5GB memory waste is
      usually unacceptable.
      
      Fortunatelly, almost all users don't use max latency feature.
      The max latency buffer can be disabled easily.
      
      This patch shrink buffer size of the max latency buffer if
      unnecessary.
      
      Signed-off-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      LKML-Reference: <20100701104554.DA2D.A69D9226@jp.fujitsu.com>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      ef710e10
  2. Jul 20, 2010
    • Lai Jiangshan's avatar
      tracing: Reduce latency and remove percpu trace_seq · bc289ae9
      Lai Jiangshan authored
      
      __print_flags() and __print_symbolic() use percpu trace_seq:
      
      1) Its memory is allocated at compile time, it wastes memory if we don't use tracing.
      2) It is percpu data and it wastes more memory for multi-cpus system.
      3) It disables preemption when it executes its core routine
         "trace_seq_printf(s, "%s: ", #call);" and introduces latency.
      
      So we move this trace_seq to struct trace_iterator.
      
      Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
      LKML-Reference: <4C078350.7090106@cn.fujitsu.com>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      bc289ae9
    • Richard Kennedy's avatar
      trace: Reorder struct ring_buffer_per_cpu to remove padding on 64bit · 985023de
      Richard Kennedy authored
      
      Reorder structure to remove 8 bytes of padding on 64 bit builds.
      This shrinks the size to 128 bytes so allowing allocation from a smaller
      slab & needed one fewer cache lines.
      
      Signed-off-by: default avatarRichard Kennedy <richard@rsk.demon.co.uk>
      LKML-Reference: <1269516456.2054.8.camel@localhost>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      985023de
    • Li Zefan's avatar
      tracing: Allow to disable cmdline recording · e870e9a1
      Li Zefan authored
      
      We found that even enabling a single trace event that will rarely be
      triggered can add big overhead to context switch.
      
      (lmbench context switch test)
       -------------------------------------------------
       2p/0K 2p/16K 2p/64K 8p/16K 8p/64K 16p/16K 16p/64K
       ctxsw  ctxsw  ctxsw ctxsw  ctxsw   ctxsw   ctxsw
      ------ ------ ------ ------ ------ ------- -------
        2.19   2.3   2.21   2.56   2.13     2.54    2.07
        2.39   2.51  2.35   2.75   2.27     2.81    2.24
      
      The overhead is 6% ~ 11%.
      
      It's because when a trace event is enabled 3 tracepoints (sched_switch,
      sched_wakeup, sched_wakeup_new) will be activated to map pid to cmdname.
      
      We'd like to avoid this overhead, so add a trace option '(no)record-cmd'
      to allow to disable cmdline recording.
      
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      LKML-Reference: <4C2D57F4.2050204@cn.fujitsu.com>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      e870e9a1
  3. Jul 17, 2010
  4. Jul 16, 2010
  5. Jul 15, 2010
  6. Jul 12, 2010
  7. Jul 06, 2010
  8. Jul 05, 2010
    • Masami Hiramatsu's avatar
      perf probe: Support static and global variables · b7dcb857
      Masami Hiramatsu authored
      
      Add static and global variables support to perf probe.
      This allows user to trace non-local variables (and
      structure members) at probe points.
      
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <20100519195749.2885.17451.stgit@localhost6.localdomain6>
      Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
      Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      b7dcb857
    • Masami Hiramatsu's avatar
      perf probe: Support tracing an entry of array · b2a3c12b
      Masami Hiramatsu authored
      
      Add array-entry tracing support to perf probe. This enables to trace an entry
      of array which is indexed by constant value, e.g. array[0].
      
      For example:
      
        $ perf probe -a 'bio_split bi->bi_io_vec[0]'
      
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <20100519195742.2885.5344.stgit@localhost6.localdomain6>
      Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
      Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      b2a3c12b
    • Masami Hiramatsu's avatar
      perf probe: Support "string" type · 73317b95
      Masami Hiramatsu authored
      
      Support string type casting to event argument. If perf-probe finds an argument
      casted as string, it ensures the target variable is "(unsigned/signed) char
      *(or []). perf-probe also adds dereference if the target is a pointer.
      
      So, both of 'char buf[10];' and 'char *buf;' can be accessed by 'buf:string'
      
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <20100519195734.2885.1666.stgit@localhost6.localdomain6>
      Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
      Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      73317b95
    • Masami Hiramatsu's avatar
      tracing/kprobes: Support "string" type · e09c8614
      Masami Hiramatsu authored
      
      Support string type tracing and printing in kprobe-tracer.
      
      This allows user to trace string data in kernel including __user data. Note
      that sometimes __user data may not be accessed if it is paged-out (sorry, but
      kprobes operation should be done in atomic, we can not wait for page-in).
      
      Commiter note: Fixed up conflicts with b7e2ecef.
      
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <20100519195724.2885.18788.stgit@localhost6.localdomain6>
      Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
      Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      e09c8614
    • Cyrill Gorcunov's avatar
      perf, x86: P4 PMU -- redesign cache events · 39ef13a4
      Cyrill Gorcunov authored
      
      To support cache events we have reserved the low 6 bits in
      hw_perf_event::config (which is a part of CCCR register
      configuration actually).
      
      These bits represent Replay Event mertic enumerated in
      enum P4_PEBS_METRIC. The caller should not care about
      which exact bits should be set and how -- the caller
      just chooses one P4_PEBS_METRIC entity and puts it into
      the config. The kernel will track it and set appropriate
      additional MSR registers (metrics) when needed.
      
      The reason for this redesign was the PEBS enable bit, which
      should not be set until DS (and PEBS sampling) support will
      be implemented properly.
      
      TODO
      ====
      
       - PEBS sampling (note it's tricky and works with _one_ counter only
         so for HT machines it will be not that easy to handle both threads)
      
       - tracking of PEBS registers state, a user might need to turn
         PEBS off completely (ie no PEBS enable, no UOP_tag) but some
         other event may need it, such events clashes and should not
         run simultaneously, at moment we just don't support such events
      
       - eventually export user space bits in separate header which will
         allow user apps to configure raw events more conveniently.
      
      Signed-off-by: default avatarCyrill Gorcunov <gorcunov@openvz.org>
      Signed-off-by: default avatarLin Ming <ming.m.lin@intel.com>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <1278295769.9540.15.camel@minggr.sh.intel.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      39ef13a4
    • Ingo Molnar's avatar
      Merge commit 'v2.6.35-rc4' into perf/core · 08f8ba07
      Ingo Molnar authored
      
      Merge reason: Pick up the latest perf fixes
      
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      08f8ba07
  9. Jul 04, 2010
  10. Jul 03, 2010
  11. Jul 02, 2010
Loading