lkml.org 
[lkml]   [2005]   [Apr]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: AMD64 Machine hardlocks when using memset
Robert wrote:
> It does run visibly slower

The x86_64 memset(), both in user space and the kernel, for whatever gcc
I have, and for a current kernel, uses the "repz stos" or "rep stosq"
prefixed instruction for the bulk of the copy. This combination is a
long running, interruptible Intel string instruction that loops on
itself until the CX register decrements to zero.

Was your windows app using "stos"?

I'll wager a nickel that the actual crash you see comes when the
processor has to handle an interrupt while in the middle of this
instruction.

I'll wager a dime it's hardware, though interrupt activity may be
required to provoke it.

--
I won't rest till it's the best ...
Programmer, Linux Scalability
Paul Jackson <pj@engr.sgi.com> 1.650.933.1373, 1.925.600.0401
-
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: 2005-04-06 13:31    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site