1. 12 Nov, 2008 7 commits
    • Frederic Weisbecker's avatar
      tracing/function-return-tracer: make the function return tracer lockless · 62d59d17
      Frederic Weisbecker authored
      Impact: remove spinlocks and irq disabling in function return tracer.
      
      I've tried to figure out all of the race condition that could happen
      when the tracer pushes or pops a return address trace to/from the
      current thread_info.
      
      Theory:
      
      _ One thread can only execute on one cpu at a time. So this code
        doesn't need to be SMP-safe. Just drop the spinlock.
      
      _ The only race could happen between the current thread and an
        interrupt. If an interrupt is raised, it will increase the index of
        the return stack storage and then execute until the end of the
        tracing to finally free the index it used. We don't need to disable
        irqs.
      
      This is theorical. In practice, I've tested it with a two-core SMP and
      had no problem at all. Perhaps -tip testing could confirm it.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      62d59d17
    • Ingo Molnar's avatar
      Merge branches 'tracing/fastboot', 'tracing/function-return-tracer' and... · cb9382e5
      Ingo Molnar authored
      Merge branches 'tracing/fastboot', 'tracing/function-return-tracer' and 'tracing/ring-buffer' into tracing/core
      cb9382e5
    • Steven Rostedt's avatar
      ring-buffer: fix deadlock from reader_lock in read_start · 642edba5
      Steven Rostedt authored
      Impact: deadlock fix in ring_buffer_read_start
      
      The ring_buffer_iter_reset was called from ring_buffer_read_start
      where both grabbed the reader_lock.
      
      This patch separates out the internals of ring_buffer_iter_reset
      to its own function so that both APIs may grab the reader_lock.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      642edba5
    • Frederic Weisbecker's avatar
      tracing/fastboot: Use the ring-buffer timestamp for initcall entries · 74239072
      Frederic Weisbecker authored
      Impact: Split the boot tracer entries in two parts: call and return
      
      Now that we are using the sched tracer from the boot tracer, we want
      to use the same timestamp than the ring-buffer to have consistent time
      captures between sched events and initcall events.
      
      So we get rid of the old time capture by the boot tracer and split the
      initcall events in two parts: call and return. This way we have the
      ring buffer timestamp of both.
      
      An example trace:
      
      [   27.904149584] calling  net_ns_init+0x0/0x1c0 @ 1
      [   27.904429624] initcall net_ns_init+0x0/0x1c0 returned 0 after 0 msecs
      [   27.904575926] calling  reboot_init+0x0/0x20 @ 1
      [   27.904655399] initcall reboot_init+0x0/0x20 returned 0 after 0 msecs
      [   27.904800228] calling  sysctl_init+0x0/0x30 @ 1
      [   27.905142914] initcall sysctl_init+0x0/0x30 returned 0 after 0 msecs
      [   27.905287211] calling  ksysfs_init+0x0/0xb0 @ 1
       ##### CPU 0 buffer started ####
                  init-1     [000]    27.905395:      1:120:R   + [001]    11:115:S
       ##### CPU 1 buffer started ####
                <idle>-0     [001]    27.905425:      0:140:R ==> [001]    11:115:R
                  init-1     [000]    27.905426:      1:120:D ==> [000]     0:140:R
                <idle>-0     [000]    27.905431:      0:140:R   + [000]     4:115:S
                <idle>-0     [000]    27.905451:      0:140:R ==> [000]     4:115:R
           ksoftirqd/0-4     [000]    27.905456:      4:115:S ==> [000]     0:140:R
                 udevd-11    [001]    27.905458:     11:115:R   + [001]    14:115:R
                <idle>-0     [000]    27.905459:      0:140:R   + [000]     4:115:S
                <idle>-0     [000]    27.905462:      0:140:R ==> [000]     4:115:R
                 udevd-11    [001]    27.905462:     11:115:R ==> [001]    14:115:R
           ksoftirqd/0-4     [000]    27.905467:      4:115:S ==> [000]     0:140:R
                <idle>-0     [000]    27.905470:      0:140:R   + [000]     4:115:S
                <idle>-0     [000]    27.905473:      0:140:R ==> [000]     4:115:R
           ksoftirqd/0-4     [000]    27.905476:      4:115:S ==> [000]     0:140:R
                <idle>-0     [000]    27.905479:      0:140:R   + [000]     4:115:S
                <idle>-0     [000]    27.905482:      0:140:R ==> [000]     4:115:R
           ksoftirqd/0-4     [000]    27.905486:      4:115:S ==> [000]     0:140:R
                 udevd-14    [001]    27.905499:     14:120:X ==> [001]    11:115:R
                 udevd-11    [001]    27.905506:     11:115:R   + [000]     1:120:D
                <idle>-0     [000]    27.905515:      0:140:R ==> [000]     1:120:R
                 udevd-11    [001]    27.905517:     11:115:S ==> [001]     0:140:R
      [   27.905557107] initcall ksysfs_init+0x0/0xb0 returned 0 after 3906 msecs
      [   27.905705736] calling  init_jiffies_clocksource+0x0/0x10 @ 1
      [   27.905779239] initcall init_jiffies_clocksource+0x0/0x10 returned 0 after 0 msecs
      [   27.906769814] calling  pm_init+0x0/0x30 @ 1
      [   27.906853627] initcall pm_init+0x0/0x30 returned 0 after 0 msecs
      [   27.906997803] calling  pm_disk_init+0x0/0x20 @ 1
      [   27.907076946] initcall pm_disk_init+0x0/0x20 returned 0 after 0 msecs
      [   27.907222556] calling  swsusp_header_init+0x0/0x30 @ 1
      [   27.907294325] initcall swsusp_header_init+0x0/0x30 returned 0 after 0 msecs
      [   27.907439620] calling  stop_machine_init+0x0/0x50 @ 1
                  init-1     [000]    27.907485:      1:120:R   + [000]     2:115:S
                  init-1     [000]    27.907490:      1:120:D ==> [000]     2:115:R
              kthreadd-2     [000]    27.907507:      2:115:R   + [001]    15:115:R
                <idle>-0     [001]    27.907517:      0:140:R ==> [001]    15:115:R
              kthreadd-2     [000]    27.907517:      2:115:D ==> [000]     0:140:R
                <idle>-0     [000]    27.907521:      0:140:R   + [000]     4:115:S
                <idle>-0     [000]    27.907524:      0:140:R ==> [000]     4:115:R
                 udevd-15    [001]    27.907527:     15:115:D   + [000]     2:115:D
           ksoftirqd/0-4     [000]    27.907537:      4:115:S ==> [000]     2:115:R
                 udevd-15    [001]    27.907537:     15:115:D ==> [001]     0:140:R
              kthreadd-2     [000]    27.907546:      2:115:R   + [000]     1:120:D
              kthreadd-2     [000]    27.907550:      2:115:S ==> [000]     1:120:R
                  init-1     [000]    27.907584:      1:120:R   + [000]    15:  0:D
                  init-1     [000]    27.907589:      1:120:R   + [000]     2:115:S
                  init-1     [000]    27.907593:      1:120:D ==> [000]    15:  0:R
                 udevd-15    [000]    27.907601:     15:  0:S ==> [000]     2:115:R
       ##### CPU 0 buffer started ####
              kthreadd-2     [000]    27.907616:      2:115:R   + [001]    16:115:R
       ##### CPU 1 buffer started ####
                <idle>-0     [001]    27.907620:      0:140:R ==> [001]    16:115:R
              kthreadd-2     [000]    27.907621:      2:115:D ==> [000]     0:140:R
                 udevd-16    [001]    27.907625:     16:115:D   + [000]     2:115:D
                <idle>-0     [000]    27.907628:      0:140:R   + [000]     4:115:S
                 udevd-16    [001]    27.907629:     16:115:D ==> [001]     0:140:R
                <idle>-0     [000]    27.907631:      0:140:R ==> [000]     4:115:R
           ksoftirqd/0-4     [000]    27.907636:      4:115:S ==> [000]     2:115:R
              kthreadd-2     [000]    27.907644:      2:115:R   + [000]     1:120:D
              kthreadd-2     [000]    27.907647:      2:115:S ==> [000]     1:120:R
                  init-1     [000]    27.907657:      1:120:R   + [001]    16:  0:D
                <idle>-0     [001]    27.907666:      0:140:R ==> [001]    16:  0:R
      [   27.907703862] initcall stop_machine_init+0x0/0x50 returned 0 after 0 msecs
      [   27.907850704] calling  filelock_init+0x0/0x30 @ 1
      [   27.907926573] initcall filelock_init+0x0/0x30 returned 0 after 0 msecs
      [   27.908071327] calling  init_script_binfmt+0x0/0x10 @ 1
      [   27.908165195] initcall init_script_binfmt+0x0/0x10 returned 0 after 0 msecs
      [   27.908309461] calling  init_elf_binfmt+0x0/0x10 @ 1
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      74239072
    • Frederic Weisbecker's avatar
      tracing/fastboot: move boot tracer structs and funcs into their own header. · 3f5ec136
      Frederic Weisbecker authored
      Impact: Cleanups on the boot tracer and ftrace
      
      This patch bring some cleanups about the boot tracer headers. The
      functions and structures of this tracer have nothing related to ftrace
      and should have so their own header file.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      3f5ec136
    • Ingo Molnar's avatar
    • Ingo Molnar's avatar
      Merge branches 'tracing/ftrace' and 'tracing/urgent' into tracing/core · d06bbd66
      Ingo Molnar authored
      Conflicts:
      	kernel/trace/ring_buffer.c
      d06bbd66
  2. 11 Nov, 2008 33 commits