lkml.org 
[lkml]   [2008]   [Feb]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Linux 2.6.25-rc2
On Wed, 27 Feb 2008 15:32:52 -0800 (PST) Christoph Lameter <clameter@sgi.com> wrote:

> On Tue, 19 Feb 2008, Mathieu Desnoyers wrote:
>
> > incrementing the variable with a "++" when interrupts are not disabled.
> > It's not an atomic add and it's racy. The code within stat() does
> > exactly this.
>
> Yes but that is only for used for statistics which can be racy. Note that
> the VM event statistics also can be racy.
>

Doing ++ on a u32 _is_ atomic wrt interrupts on x86 and probably lots of
other architectures, so we're OK using unsigned there. But on some other
architectures ++ on u32 is not atomic wrt interrutps, so they should use
atomic_t or some other arch-specific mechanism.

And guess what? It's already all been done: local_t.


\
 
 \ /
  Last update: 2008-02-28 03:01    [W:0.147 / U:0.180 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site