lkml.org 
[lkml]   [2006]   [Mar]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [patch] i386 spinlocks: disable interrupts only if we enabled them
Andrew Morton wrote:
> Benjamin LaHaise <bcrl@kvack.org> wrote:
>
>>On Wed, Mar 08, 2006 at 01:43:08AM +0100, Ingo Molnar wrote:
>> > we dont inline that code anymore. So i think the optimization is fine.
>>
>> Why is that? It adds memory traffic that has to be synchronized
>> before the lock occurs and clobbered registers now in the caller.
>
>
> Is the inlined lock;decb+jns likely to worsen the text size? I doubt it.
> Overall text will get bigger due to the out-of-line stuff, but that's OK.
>
> I'm sure we went over all this, but I don't recall the thinking.

Seems like a very good idea not to clobber any registers in
lock fastpaths. I don't see how that could have been a win
(especially for i386) but still, Ingo must have had a reason
behind it.

--
SUSE Labs, Novell Inc.
Send instant messages to your online friends http://au.messenger.yahoo.com

-
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: 2006-03-08 09:54    [W:0.072 / U:0.072 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site