[lkml]   [2002]   [Aug]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] [2.5] asm-generic/atomic.h and changes to arm, parisc, mips, m68k, sh, cris to use it

On 9 Aug 2002, Luca Barbieri wrote:

> > The compiler can cache the value in a register
> It shouldn't since it is volatile and the machine has instructions with
> memory operands.

volatile is no guarantee for that:

volatile int x;

void f(int y)
x += y;

move.l x,%d0
add.l 8(%a6),%d0
move.l %d0,x

I agree that volatile should avoid caching, but it does not guarantee an
atomic modify.

bye, Roman

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:27    [from the cache]
©2003-2014 Jasper Spaans. hosted at Digital Ocean