lkml.org 
[lkml]   [2003]   [Nov]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: ext3 performance inconsistencies, 2.4/2.6

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.

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

That would be interesting.

Linus

-
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: 2009-11-18 23:46    [W:0.047 / U:5.448 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site