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

From: Shailabh Nagar
Date: Mon Jun 26 2006 - 13:59:33 EST


Andrew Morton wrote:

On Mon, 26 Jun 2006 10:33:04 -0700
Jay Lan <jlan@xxxxxxx> wrote:



Will that work for everyone ?


As long as the per-pid delayacct struct has a pointer to the per-tgid
data struct and deoes not need to go through the loop on every exit.



My brain is wilting, and time is moving along.

Balbir, are you able to summarise where we stand wrt
per-task-delay-accounting-* now?


Andrew,

I'm maintaining per-task delay accouting and taskstats interface patches so I'll take the liberty to reply :-)

What problem have we identified? How close are we to finding agreeable
solutions to them?


The main problems identified are:

1. extra sending of per-tgid stats on every thread exit
2. unnecessary send of per-tgid stats when there are no listeners
3. unnecessary linkage of delayacct accumalation into per-tgid stats with sending out of taskstats

All three have an acceptable solution.
1. & 3. are going to be addressed in a patch I'm sending out shortly.
2. in a separate patch also being sent out shortly.

My general sense is that there's some rework needed, and that rework will
affect the userspace interfaces, which is a problem for a 2.6.18 merge.


The rework will affect the number of per-tgid records that userspace sees (fewer), not the format or any of the
other details regarding the genetlink interface.
Will that be a problem for userspace ?

--Shailabh

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