lkml.org 
[lkml]   [2007]   [Aug]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 0/24] make atomic_read() behave consistently across all architectures
Linus Torvalds wrote:

> - in other words, the *only* possible meaning for "volatile" is a purely
> single-CPU meaning. And if you only have a single CPU involved in the
> process, the "volatile" is by definition pointless (because even
> without a volatile, the compiler is required to make the C code appear
> consistent as far as a single CPU is concerned).

I assume you mean "except for IO-related code and 'random' values like
jiffies" as you mention later on? I assume other values set in
interrupt handlers would count as "random" from a volatility perspective?

> So anybody who argues for "volatile" fixing bugs is fundamentally
> incorrect. It does NO SUCH THING. By arguing that, such people only show
> that you have no idea what they are talking about.

What about reading values modified in interrupt handlers, as in your
"random" case? Or is this a bug where the user of atomic_read() is
invalidly expecting a read each time it is called?

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: 2007-08-17 20:59    [W:0.227 / U:1.808 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site