Bug 15192

Summary:	netperf ~50% regression with 2.6.33-rc1, bisect to 1b9508f
Product:	Process Management	Reporter:	Rafael J. Wysocki (rjw)
Component:	Scheduler	Assignee:	Ingo Molnar (mingo)
Status:	CLOSED CODE_FIX
Severity:	normal	CC:	fullung, rm+bko
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	2.6.33-rc1	Subsystem:
Regression:	Yes	Bisected commit-id:
Bug Depends on:
Bug Blocks:	14885

Description Rafael J. Wysocki 2010-01-31 22:45:29 UTC

Subject    : netperf ~50% regression with 2.6.33-rc1, bisect to 1b9508f
Submitter  : Lin Ming <ming.m.lin@intel.com>
Date       : 2010-01-25 10:03
References : http://marc.info/?l=linux-kernel&m=126441481427331&w=4
Handled-By : Mike Galbraith <efault@gmx.de>
Handled-By : Peter Zijlstra <peterz@infradead.org>

This entry is being used for tracking a regression from 2.6..  Please don't
close it until the problem is fixed in the mainline.

Comment 1 Rafael J. Wysocki 2010-01-31 22:54:23 UTC

Bisection turned up:

commit 1b9508f6831e10d53256825de8904caa22d1ca2c
Author: Mike Galbraith <efault@gmx.de>
Date:   Wed Nov 4 17:53:50 2009 +0100

    sched: Rate-limit newidle

    Rate limit newidle to migration_cost. It's a win for all
    stages of sysbench oltp tests.

    Signed-off-by: Mike Galbraith <efault@gmx.de>
    LKML-Reference: <new-submission>
    Signed-off-by: Ingo Molnar <mingo@elte.hu>

First-Bad-Commit : 1b9508f6831e10d53256825de8904caa22d1ca2c

Comment 2 Rafael J. Wysocki 2010-02-02 20:38:27 UTC

On Monday 01 February 2010, Mike Galbraith wrote:
> On Mon, 2010-02-01 at 01:22 +0100, Rafael J. Wysocki wrote:
> > This message has been generated automatically as a part of a report
> > of recent regressions.
> > 
> > The following bug entry is on the current list of known regressions
> > from 2.6.32.  Please verify if it still should be listed and let me know
> > (either way).
> 
> Yes, it should remain open.  We're currently waiting for some data from
> Lin Ming.  The regression itself isn't making much sense.. a kernel with
> NEWIDLE disabled should show the same performance, but does not.

Comment 3 Albert Strasheim 2010-02-19 12:46:38 UTC

Sounds a lot like the bug I reported here:

https://bugzilla.redhat.com/show_bug.cgi?id=559943

Intel e1000e NIC in a Sun X6270 blade.

Comment 4 Rafael J. Wysocki 2010-02-21 20:42:17 UTC

Patch : http://patchwork.kernel.org/patch/78544/
Handled-By : Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>

Comment 5 Rafael J. Wysocki 2010-03-22 21:29:37 UTC

Fixed by commit d306ebc28649b89877a22158fe0076f06cc46f60 .