lkml.org 
[lkml]   [2007]   [Jul]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [rfc][patch 2/2] x86_64: FIFO ticket spinlocks
On Mon, Jul 16, 2007 at 11:26:46AM +0200, Ingo Molnar wrote:
>
> * Nick Piggin <npiggin@suse.de> wrote:
>
> > [...] trylock is more significantly slower, but they are relatively
> > rare.
>
> trylock is the main thing that the spinlock debugging code uses, and
> SPINLOCK_DEBUG is frequently enabled by distro kernels. OTOH, the cost
> looks like to be +5 instructions, right? Still ...

Which trylocks do you mean? The lockbreak spinlocks use trylock, but
those are not used with the ticket version.

I wouldn't be against adding an option between either of the lock
types, if there was value in it. But I would like to default ticket
locks to "y", at least in -rc kernels, in order to see if performance
goes down anywhere.
-
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: 2007-07-16 11:47    [W:0.063 / U:0.756 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site