lkml.org 
[lkml]   [2007]   [Aug]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 6/24] make atomic_read() behave consistently on frv
David Howells wrote:
> Chris Snook <csnook@redhat.com> wrote:
>
>> To head off the criticism, I admit this is an oversimplification, and true
>> busy-waiters should be using cpu_relax(), which contains a barrier.
>
> Why would you want to use cpu_relax()? That's there to waste time efficiently,
> isn't it? Shouldn't you be using smp_rmb() or something like that?
>
> David

cpu_relax() contains a barrier, so it should do the right thing. For
non-smp architectures, I'm concerned about interacting with interrupt
handlers. Some drivers do use atomic_* operations.

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

\
 
 \ /
  Last update: 2007-08-10 21:57    [W:0.217 / U:0.828 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site