15 Dec
2009
15 Dec
'09
5:14 a.m.
Paul Davis wrote:
On Mon, Dec 14, 2009 at 2:45 PM, Stephen Sinclair
<radarsat1(a)gmail.com> wrote:
On SPARC, 32-bit reads and writes were atomic, but unlike most other
processors, it was not able to lock the bus for atomic read-modify-write
operations, so 8 bits were used to implement a lock; see
<http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=arch/sparc/include/asm/atomic_32.h>.
Best regards,
Clemens
As far as I understand
this doesn't happen as long as you stick to the word size of the
architecture. (Anyone please correct me if I'm wrong about that.)
unbelievably, perhaps, this was not true on SPARC. atomicity was only
guaranteed for 24 bits of a 32 bit value.