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

Jay Lan
2006-06-21T22:19:05Z

Andrew Morton wrote:
>On Wed, 21 Jun 2006 14:45:01 -0700
>Jay Lan <jlan@engr.sgi.com> wrote:
>
>
>>>Won't it suffice to make delivery of these stats best effort, with
>>>userspace dealing with missing data,
>>>
>>How do you recover the missed data?
>>
>
>I suspect the best we can do is to let userspace know that data was lost.
>Is the -ENOBUFS reliable?
>

We need to reduce that to an acceptable rate. In the real life, the rate
should be
must less. Under this test, i have one drop every < 5 minutes. I will
talk to
our deamon expert to see how we can improve it... and get a better define of
"acceptable rate".

- jay

>
>>>rather than risk delaying exits ? The cases where exits are so
>>>frequent as in this program should be
>>>
>>This is very true. However, it was a 2p IA64 machine. I am too frightened to
>>speak "512p"...
>>
>
>If we have 511 CPUs generating data faster than one CPU can handle it,
>something bad will happen. We either throttle the 511 CPUs or drop data.
>
>