lkml.org 
[lkml]   [2008]   [May]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: 2.6.24.7-rt8

On Wed, 21 May 2008, Mike Galbraith wrote:
> On Tue, 2008-05-20 at 00:46 -0400, Steven Rostedt wrote:
> > We are pleased to announce the 2.6.24.7-rt8 tree, which can be
> > downloaded from the location:
> >
> > http://rt.et.redhat.com/download/
>
> I ran mysql+oltp (ro) on 2.6.24.7-rt7 and 2.6.25-rt2 to compare
> throughput to their parent trees, and ended up with strange (and
> verified) looking performance curves for both trees. The changes in
> 2.6.24.7-rt8 and 2.6.25.4-rt3 cured the primary oddities.

The difference between 24-rt7 and 24-rt8 as well as with 25-rt2 and 25-rt3
is the deserialization of rwlocks. The rt patch as always serialized
readers to allow for priority inheritance with rwlocks. I wrote a patch to
break that and allow for multiple readers and still keep the priority
inheritance.

Your test probably had a bottle neck on a rwlock (same for rwsems)
somewhere that the new code solved.

-- Steve


\
 
 \ /
  Last update: 2008-05-21 14:49    [W:0.078 / U:0.200 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site