lkml.org 
[lkml]   [2003]   [Nov]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: ext3 performance inconsistencies, 2.4/2.6
From
Date
On Tue, 2003-11-04 at 15:30, Linus Torvalds wrote:
> On Tue, 4 Nov 2003, Bill Rugolsky Jr. wrote:
> >
> > Unless bonnie++ is using the _unlocked() variants, it might be an issue of
> > the mutex overhead from NPTL v. LinuxThreads. Red Hat 9 has its share
> > of NPTL bugs.
>
> Hmm.. That would easily explain the differences, since NPTL will trigger
> both on 2.6.0 and the RH-2.4 kernel, but not on the standard 2.4.22
> kernel.
>
> But there really should be zero contention on the stdio data structures,
> so the locking would have to be _seriously_ broken to make that kind o
> fdifference (not necessarily buggy, but seriously badly implemented).
>
> A non-contended lock should be at most one locked instruction if well
> done, both on LinuxThreads and NPTL.

Good point...

A truncated strace under 2.4.22 is here:
http://groove.jpj.net/bonnie-strace-trunc

It's incomplete, but shows the putc calls.

> > It is probably worth rerunning the tests with LD_ASSUME_KERNEL=2.4.1 on
> > the Red Hat kernel.
>
> That would be interesting.

Tests are running now. Updates as events warrant.

-Paul

-
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: 2005-03-22 13:58    [W:0.055 / U:2.032 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site