1. 03 12月, 2008 1 次提交
  2. 29 11月, 2008 1 次提交
  3. 23 11月, 2008 4 次提交
    • S
      trace: fix compiler warning in branch profiler · 0429149f
      Steven Rostedt 提交于
      Impact: fix compiler warning
      
      The ftrace_pointers used in the branch profiler are constant values.
      They should never change. But the compiler complains when they are
      passed into the debugfs_create_file as a data pointer, because the
      function discards the qualifier.
      
      This patch typecasts the parameter to debugfs_create_file back to
      a void pointer. To remind the callbacks that they are pointing to
      a constant value, I also modified the callback local pointers to
      be const struct ftrace_pointer * as well.
      Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      0429149f
    • S
      trace: profile all if conditionals · 2bcd521a
      Steven Rostedt 提交于
      Impact: feature to profile if statements
      
      This patch adds a branch profiler for all if () statements.
      The results will be found in:
      
        /debugfs/tracing/profile_branch
      
      For example:
      
         miss      hit    %        Function                  File              Line
       ------- ---------  -        --------                  ----              ----
             0        1 100 x86_64_start_reservations      head64.c             127
             0        1 100 copy_bootdata                  head64.c             69
             1        0   0 x86_64_start_kernel            head64.c             111
            32        0   0 set_intr_gate                  desc.h               319
             1        0   0 reserve_ebda_region            head.c               51
             1        0   0 reserve_ebda_region            head.c               47
             0        1 100 reserve_ebda_region            head.c               42
             0        0   X maxcpus                        main.c               165
      
      Miss means the branch was not taken. Hit means the branch was taken.
      The percent is the percentage the branch was taken.
      
      This adds a significant amount of overhead and should only be used
      by those analyzing their system.
      Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      2bcd521a
    • S
      trace: branch profiling should not print percent without data · bac28bfe
      Steven Rostedt 提交于
      Impact: cleanup on output of branch profiler
      
      When a branch has not been taken, it does not make sense to show
      a percentage incorrect or hit. This patch changes the behaviour
      to print out a 'X' when the branch has not been executed yet.
      
      For example:
      
       correct incorrect  %        Function                  File              Line
       ------- ---------  -        --------                  ----              ----
          2096        0   0 do_arch_prctl                  process_64.c         832
             0        0   X do_arch_prctl                  process_64.c         804
          2604        0   0 IS_ERR                         err.h                34
        130228     5765   4 __switch_to                    process_64.c         673
             0        0   X enable_TSC                     process_64.c         448
             0        0   X disable_TSC                    process_64.c         431
      Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      bac28bfe
    • S
      trace: consolidate unlikely and likely profiler · 45b79749
      Steven Rostedt 提交于
      Impact: clean up to make one profiler of like and unlikely tracer
      
      The likely and unlikely profiler prints out the file and line numbers
      of the annotated branches that it is profiling. It shows the number
      of times it was correct or incorrect in its guess. Having two
      different files or sections for that matter to tell us if it was a
      likely or unlikely is pretty pointless. We really only care if
      it was correct or not.
      Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      45b79749
  4. 16 11月, 2008 2 次提交
  5. 13 11月, 2008 4 次提交
  6. 12 11月, 2008 2 次提交
    • S
      tracing: likely/unlikely branch annotation tracer · 52f232cb
      Steven Rostedt 提交于
      Impact: new likely/unlikely branch tracer
      
      This patch adds a way to record the instances of the likely() and unlikely()
      branch condition annotations.
      
      When "unlikely" is set in /debugfs/tracing/iter_ctrl the unlikely conditions
      will be added to any of the ftrace tracers. The change takes effect when
      a new tracer is passed into the current_tracer file.
      
      For example:
      
       bash-3471  [003]   357.014755: [INCORRECT] sched_info_dequeued:sched_stats.h:177
       bash-3471  [003]   357.014756: [correct] update_curr:sched_fair.c:489
       bash-3471  [003]   357.014758: [correct] calc_delta_fair:sched_fair.c:411
       bash-3471  [003]   357.014759: [correct] account_group_exec_runtime:sched_stats.h:356
       bash-3471  [003]   357.014761: [correct] update_curr:sched_fair.c:489
       bash-3471  [003]   357.014763: [INCORRECT] calc_delta_fair:sched_fair.c:411
       bash-3471  [003]   357.014765: [correct] calc_delta_mine:sched.c:1279
      
      Which shows the normal tracer heading, as well as whether the condition was
      correct "[correct]" or was mistaken "[INCORRECT]", followed by the function,
      file name and line number.
      Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      52f232cb
    • S
      tracing: profile likely and unlikely annotations · 1f0d69a9
      Steven Rostedt 提交于
      Impact: new unlikely/likely profiler
      
      Andrew Morton recently suggested having an in-kernel way to profile
      likely and unlikely macros. This patch achieves that goal.
      
      When configured, every(*) likely and unlikely macro gets a counter attached
      to it. When the condition is hit, the hit and misses of that condition
      are recorded. These numbers can later be retrieved by:
      
        /debugfs/tracing/profile_likely    - All likely markers
        /debugfs/tracing/profile_unlikely  - All unlikely markers.
      
      # cat /debug/tracing/profile_unlikely | head
       correct incorrect  %        Function                  File              Line
       ------- ---------  -        --------                  ----              ----
          2167        0   0 do_arch_prctl                  process_64.c         832
             0        0   0 do_arch_prctl                  process_64.c         804
          2670        0   0 IS_ERR                         err.h                34
         71230     5693   7 __switch_to                    process_64.c         673
         76919        0   0 __switch_to                    process_64.c         639
         43184    33743  43 __switch_to                    process_64.c         624
         12740    64181  83 __switch_to                    process_64.c         594
         12740    64174  83 __switch_to                    process_64.c         590
      
      # cat /debug/tracing/profile_unlikely | \
        awk '{ if ($3 > 25) print $0; }' |head -20
         44963    35259  43 __switch_to                    process_64.c         624
         12762    67454  84 __switch_to                    process_64.c         594
         12762    67447  84 __switch_to                    process_64.c         590
          1478      595  28 syscall_get_error              syscall.h            51
             0     2821 100 syscall_trace_leave            ptrace.c             1567
             0        1 100 native_smp_prepare_cpus        smpboot.c            1237
         86338   265881  75 calc_delta_fair                sched_fair.c         408
        210410   108540  34 calc_delta_mine                sched.c              1267
             0    54550 100 sched_info_queued              sched_stats.h        222
         51899    66435  56 pick_next_task_fair            sched_fair.c         1422
             6       10  62 yield_task_fair                sched_fair.c         982
          7325     2692  26 rt_policy                      sched.c              144
             0     1270 100 pre_schedule_rt                sched_rt.c           1261
          1268    48073  97 pick_next_task_rt              sched_rt.c           884
             0    45181 100 sched_info_dequeued            sched_stats.h        177
             0       15 100 sched_move_task                sched.c              8700
             0       15 100 sched_move_task                sched.c              8690
         53167    33217  38 schedule                       sched.c              4457
             0    80208 100 sched_info_switch              sched_stats.h        270
         30585    49631  61 context_switch                 sched.c              2619
      
      # cat /debug/tracing/profile_likely | awk '{ if ($3 > 25) print $0; }'
         39900    36577  47 pick_next_task                 sched.c              4397
         20824    15233  42 switch_mm                      mmu_context_64.h     18
             0        7 100 __cancel_work_timer            workqueue.c          560
           617    66484  99 clocksource_adjust             timekeeping.c        456
             0   346340 100 audit_syscall_exit             auditsc.c            1570
            38   347350  99 audit_get_context              auditsc.c            732
             0   345244 100 audit_syscall_entry            auditsc.c            1541
            38     1017  96 audit_free                     auditsc.c            1446
             0     1090 100 audit_alloc                    auditsc.c            862
          2618     1090  29 audit_alloc                    auditsc.c            858
             0        6 100 move_masked_irq                migration.c          9
             1      198  99 probe_sched_wakeup             trace_sched_switch.c 58
             2        2  50 probe_wakeup                   trace_sched_wakeup.c 227
             0        2 100 probe_wakeup_sched_switch      trace_sched_wakeup.c 144
          4514     2090  31 __grab_cache_page              filemap.c            2149
         12882   228786  94 mapping_unevictable            pagemap.h            50
             4       11  73 __flush_cpu_slab               slub.c               1466
        627757   330451  34 slab_free                      slub.c               1731
          2959    61245  95 dentry_lru_del_init            dcache.c             153
           946     1217  56 load_elf_binary                binfmt_elf.c         904
           102       82  44 disk_put_part                  genhd.h              206
             1        1  50 dst_gc_task                    dst.c                82
             0       19 100 tcp_mss_split_point            tcp_output.c         1126
      
      As you can see by the above, there's a bit of work to do in rethinking
      the use of some unlikelys and likelys. Note: the unlikely case had 71 hits
      that were more than 25%.
      
      Note:  After submitting my first version of this patch, Andrew Morton
        showed me a version written by Daniel Walker, where I picked up
        the following ideas from:
      
        1)  Using __builtin_constant_p to avoid profiling fixed values.
        2)  Using __FILE__ instead of instruction pointers.
        3)  Using the preprocessor to stop all profiling of likely
             annotations from vsyscall_64.c.
      
      Thanks to Andrew Morton, Arjan van de Ven, Theodore Tso and Ingo Molnar
      for their feed back on this patch.
      
      (*) Not ever unlikely is recorded, those that are used by vsyscalls
       (a few of them) had to have profiling disabled.
      Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Theodore Tso <tytso@mit.edu>
      Cc: Arjan van de Ven <arjan@infradead.org>
      Cc: Steven Rostedt <srostedt@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      1f0d69a9