Re: [PATCH 1/2] itimers: fix racy writes to cpu_itimer fields

From: Stanislaw Gruszka
Date: Thu Sep 24 2009 - 11:54:09 EST


On Thu, 24 Sep 2009 16:48:07 +0200
Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote:

> On Thu, 2009-09-24 at 16:35 +0200, Stanislaw Gruszka wrote:
> > incr_error and error fields of struct cpu_itimer are used when calculating
> > next timer tick in check_cpu_itimers() and should not be modified without
> > tsk->sighand->siglock taken.
>
> Won't it be all-round much better to convert these things to hrtimers
> instead of adding more and more fuzz on top to make them deal with
> jiffies?

Perhaps it would, but I don't know how to do it :{ . Especially how to
precisely account user time. The only idea I have is make something like
microstate accounting (http://lwn.net/Articles/127296/), but this patch
and whole idea was rejected long time ago.

Stanislaw
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/