Re: [PATCH 0/3] tracing/perf: perf_trace_buf/perf_xxx hacks.

[Steven Rostedt]

On Thu, 2013-06-20 at 14:53 -0400, Steven Rostedt wrote:

> Oh wait, I just noticed Oleg's:
> 
> # perf record -e sched:sched_switch -p1 &
> 
> I missed that.
> 
> bah, time to re-run it.
> 


New update, after running with the above command:

[root@ixf ~]# cat perf-bench-sched.before.2 | tail -20
     Total time: 11.833 [sec]

      11.833804 usecs/op
          84503 ops/sec

 Performance counter stats for process id '1' (100 runs):

     <not counted> task-clock              
     <not counted> context-switches        
     <not counted> cpu-migrations          
     <not counted> page-faults             
     <not counted> cycles                  
   <not supported> stalled-cycles-frontend 
   <not supported> stalled-cycles-backend  
     <not counted> instructions            
     <not counted> branches                
     <not counted> branch-misses           

      11.955755673 seconds time elapsed
( +-  0.05% )

[root@ixf ~]# cat perf-bench-sched.after-2 | tail -20
     Total time: 11.490 [sec]

      11.490764 usecs/op
          87026 ops/sec

 Performance counter stats for process id '1' (100 runs):

     <not counted> task-clock              
     <not counted> context-switches        
     <not counted> cpu-migrations          
     <not counted> page-faults             
     <not counted> cycles                  
   <not supported> stalled-cycles-frontend 
   <not supported> stalled-cycles-backend  
     <not counted> instructions            
     <not counted> branches                
     <not counted> branch-misses           

      11.511847099 seconds time elapsed
( +-  0.05% )


OK, this does give us a slight improvement. Approximately 4%.

-- Steve


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