On Fri, Mar 26, 2010 at 09:23:44AM +0530, Balbir Singh wrote:
quoted text
> * Oleg Nesterov <oleg@redhat.com> [2010-03-24 21:45:50]:
> 
> > do_task_stat()->task_times() can race with getrusage(), they both can
> > try to update task->prev_Xtime at the same time.
> > 
> > Remove this bit of d180c5bc "sched: Introduce task_times() to replace
> > task_{u,s}time()".
> 
> One of the reasons for adding this accuracy was to avoid sampling
> based noise and errors that occur with utime and stime.
> 
> As long as there is no preemption during the assignment, I think we
> should be OK. 
> 
> I see two options
> 
> 1. Disable preemption around assignment
That one sounds very good.

quoted text
> 2. Remove task_times() from getrusage()
We want more accurate and what more important monotonic values
in getrusage.

Stanislaw
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