Re: Performance Stats: Kernel patch

[Bill Davidsen <davidsen@tmr.com>]

Eric Dumazet wrote:
> On Wed, 11 Apr 2007 15:59:16 +0400
> Maxim Uvarov <muvarov@ru.mvista.com> wrote:
>
>   
>> Patch adds Process Performance Statistics.
>> It make available to the user the following 
>> new per-process (thread) performance statistics:
>>    * Involuntary Context Switches
>>    * Voluntary Context Switches
>>    * Number of system calls
>>    
>> This data is useful for detecting hyperactivity 
>> patterns between processes.
>>     
>
> Your description is not very clear about the semantic of your stats.
>
> You currently returns stats only for thread(s) (not process as you claimed)
>   
I'm not sure if you were confused by his use of thread in parenthesis, 
but isn't the whole point of this to see which threads are doing what? 
Or am I misreading his result as intentional?
> Please check kernel/sys.c:k_getrusage() to see how getrusage() has to sum *lot* of individual fields to get precise process numbers (even counting stats for dead threads)
>
>   
-- 
bill davidsen <davidsen@tmr.com>
  CTO TMR Associates, Inc
  Doing interesting things with small computers since 1979