lkml.org 
[lkml]   [2010]   [Nov]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] drivers/net/tile/: on-chip network drivers for the tile architecture
From
Date
Le mercredi 03 novembre 2010 à 13:37 -0400, Chris Metcalf a écrit :
> Stephen, thanks for your feedback!
>
> On 11/3/2010 12:59 PM, Stephen Hemminger wrote:
> > 1. MUST not use volatile, see volatile-considered-harmful.txt
>
> The "harmful" use of volatile is in trying to fake out SMP. Believe me,
> with a 64-core architecture, we know our SMP guidelines. :-) Our use here
> is simply to force the compiler to issue a load, for the side-effect of
> populating the TLB, for example.
>
> However, your response does suggest that simply the syntactic use of
> "volatile" will cause a red flag for readers. I'll move this to an inline
> function in a header with a comment explaining what it's for, and use the
> function instead.

Please read Documentation/volatile-considered-harmful.txt

Then if there is a problem, we can make change to the documentation, but
volatile use in new code is _strictly_ forbidden.

ACCESS_ONCE() is your friend, we might document it in
Documentation/volatile-considered-harmful.txt



--
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: 2010-11-03 18:53    [W:0.291 / U:0.284 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site