1. 11 11月, 2008 11 次提交
  2. 10 11月, 2008 13 次提交
  3. 09 11月, 2008 11 次提交
  4. 08 11月, 2008 5 次提交
    • I
      sched: improve sched_clock() performance · 0d12cdd5
      Ingo Molnar 提交于
      in scheduler-intense workloads native_read_tsc() overhead accounts for
      20% of the system overhead:
      
       659567 system_call                              41222.9375
       686796 schedule                                 435.7843
       718382 __switch_to                              665.1685
       823875 switch_mm                                4526.7857
       1883122 native_read_tsc                          55385.9412
       9761990 total                                      2.8468
      
      this is large part due to the rdtsc_barrier() that is done before
      and after reading the TSC.
      
      But sched_clock() is not a precise clock in the GTOD sense, using such
      barriers is completely pointless. So remove the barriers and only use
      them in vget_cycles().
      
      This improves lat_ctx performance by about 5%.
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      0d12cdd5
    • S
      ftrace: display start of CPU buffer in trace output · a309720c
      Steven Rostedt 提交于
      Impact: change in trace output
      
      Because the trace buffers are per cpu ring buffers, the start of
      the trace can be confusing. If one CPU is very active at the
      end of the trace, its history will not go as far back as the
      other CPU traces.  This means that output for a particular CPU
      may not appear for the first part of a trace.
      
      To help annotate what is happening, and to prevent any more
      confusion, this patch adds a line that annotates the start of
      a CPU buffer output.
      
      For example:
      
             automount-3495  [001]   184.596443: dnotify_parent <-vfs_write
      [...]
             automount-3495  [001]   184.596449: dput <-path_put
             automount-3496  [002]   184.596450: down_read_trylock <-do_page_fault
      [...]
                 sshd-3497  [001]   184.597069: up_read <-do_page_fault
                <idle>-0     [000]   184.597074: __exit_idle <-exit_idle
      [...]
             automount-3496  [002]   184.597257: filemap_fault <-__do_fault
                <idle>-0     [003]   184.597261: exit_idle <-smp_apic_timer_interrupt
      
      Note, parsers of a trace output should always ignore any lines that
      start with a '#'.
      Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      a309720c
    • S
      ftrace: force pass of preemptoff selftest · 769c48eb
      Steven Rostedt 提交于
      Impact: preemptoff not tested in selftest
      
      Due to the BKL not being preemptable anymore, the selftest of the
      preemptoff code can not be tested. It requires that it is called
      with preemption enabled, but since the BKL is held, that is no
      longer the case.
      
      This patch simply skips those tests if it detects that the context
      is not preemptable. The following will now show up in the tests:
      
      Testing tracer preemptoff: can not test ... force PASSED
      Testing tracer preemptirqsoff: can not test ... force PASSED
      
      When the BKL is removed, or it becomes preemptable once again, then
      the tests will be performed.
      Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      769c48eb
    • M
      ftrace: align __mcount_loc sections · 7d5222a6
      Matt Fleming 提交于
      Impact: add alignment option for recordmcount.pl script
      
      Align the __mcount_loc sections so that architectures with strict
      alignment requirements need not worry about performing unaligned
      accesses.
      
      This fixes an issue where I was seeing unaligned accesses, which are not
      supported on our architecture (the results of an unaligned access are
      undefined).
      Signed-off-by: NMatt Fleming <matthew.fleming@imgtec.com>
      Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      7d5222a6
    • S
      ftrace: remove trace array ctrl · c76f0694
      Steven Rostedt 提交于
      Impact: remove obsolete variable in trace_array structure
      
      With the new start / stop method of ftrace, the ctrl variable
      in the trace_array structure is now obsolete. Remove it.
      Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      c76f0694