Re: [Patch][RFC] Disabling per-tgid stats on task exit in taskstats

[Jay Lan <jlan@engr.sgi.com>]

Hi Andrew,

Testing with all delay-accounting patches as been in your 2.6.27-mm3
tree as of 6/26 afternoon (ie, including the send-tgid-once, and
avoid-sending-without-listeners patches), i do not see measurable
performance difference with and without tgid processing when the
exit rate was controlled to around 1000 exit/sec.

As a result i am OK to not include a design of a system-wise
init-time configuration option (for per-thread group data processing)
in the taskstats interface.

The ENOBUFS i experienced in my testing would start to happen
when exit rate at around 14000 exits/sec. While our fields confirmed
that a 1000 threads exit/sec was a real, i have no reason to be
concerned of 14000 exits/sec rate. ;)

Regards,
 - jay


Andrew Morton wrote:
> On Mon, 26 Jun 2006 11:26:53 -0700
> Jay Lan <jlan@sgi.com> wrote:
> 
> 
>>>OK, please send the patch and I'll plan on sending this lot to Linus
>>>Thursdayish.
>>
>>These new patches are fresh out of Shailabh's stove (well, i have
>>seen one, but not the other yet) and i have not had chance to look
>>at them yet. No need to rush, does it?
> 
> 
> Thursday's a long way off ;)
> 
> As long as we have a high level of confidence that any remaining issues
> will be fixed within a few weeks, this code is OK for a merge.
> 
> There's a general agreement that the kernel needs this feature - people
> have been mucking around with it for years.  Let's put the effort in and
> make it happen.