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

[Shailabh Nagar <nagar@watson.ibm.com>]

Andrew Morton wrote:

>On Mon, 26 Jun 2006 10:33:04 -0700
>Jay Lan <jlan@sgi.com> 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