2.6.21-rc1: known regressions (part 3)

2.6.21-rc1: known regressions (part 3)

[Adrian Bunk]

This email lists some known regressions in 2.6.21-rc1 compared to 2.6.20
that are not yet fixed in Linus' tree.

If you find your name in the Cc header, you are either submitter of one
of the bugs, maintainer of an affectected subsystem or driver, a patch
of you caused a breakage or I'm considering you in any other way possibly
involved with one or more of these issues.

Due to the huge amount of recipients, please trim the Cc when answering.


Subject    : forcedeth: skb_over_panic
References : http://bugzilla.kernel.org/show_bug.cgi?id=8058
Submitter  : Albert Hopkins <kernel@marduk.letterboxes.org>
Status     : unknown


Subject    : natsemi ethernet card not detected correctly
References : http://lkml.org/lkml/2007/2/23/4
             http://lkml.org/lkml/2007/2/23/7
Submitter  : Bob Tracy <rct@gherkin.frus.com>
Caused-By  : Mark Brown <broonie@sirena.org.uk>
Handled-By : Mark Brown <broonie@sirena.org.uk>
Patch      : http://lkml.org/lkml/2007/2/23/142
Status     : patch available


Subject    : request_module: runaway loop modprobe net-pf-1
References : http://lkml.org/lkml/2007/2/21/206
Submitter  : YOSHIFUJI Hideaki / 吉藤英明 <yoshfuji@linux-ipv6.org>
Caused-By  : Kay Sievers <kay.sievers@vrfy.org>
             commit c353c3fb0700a3c17ea2b0237710a184232ccd7f
Handled-By : Greg KH <greg@kroah.com>
Status     : problem is being discussed


Subject    : IPV6=m, SUNRPC=y compile error
References : http://bugzilla.kernel.org/show_bug.cgi?id=8050
             http://lkml.org/lkml/2007/2/12/442
             http://lkml.org/lkml/2007/2/20/384
Submitter  : Michael-Luke Jones <mlj28@cam.ac.uk>
             Pete Clements <clem@clem.clem-digital.net>
             Sid Boyce <g3vbv@blueyonder.co.uk>
Caused-By  : Chuck Lever <chuck.lever@oracle.com>
Handled-By : YOSHIFUJI Hideaki / 吉藤英明 <yoshfuji@linux-ipv6.org>
Status     : patch available


Subject    : WARNING: "compat_agp_ioctl" undefined!
References : http://lkml.org/lkml/2007/2/21/272
Submitter  : Andreas Schwab <schwab@suse.de>
Handled-By : Dave Jones <davej@redhat.com>
Status     : patch available

Re: 2.6.21-rc1: known regressions (part 3)

[Greg KH]

On Sun, Feb 25, 2007 at 07:02:51PM +0100, Adrian Bunk wrote:
> 
> 
> Subject    : request_module: runaway loop modprobe net-pf-1
> References : http://lkml.org/lkml/2007/2/21/206
> Submitter  : YOSHIFUJI Hideaki / ???????????? <yoshfuji@linux-ipv6.org>
> Caused-By  : Kay Sievers <kay.sievers@vrfy.org>
>              commit c353c3fb0700a3c17ea2b0237710a184232ccd7f
> Handled-By : Greg KH <greg@kroah.com>
> Status     : problem is being discussed

Patch has been reverted and submitted to Linus to pull, but he's out of
town right now...

thanks,

greg k-h

2.6.21-rc1: known regressions (v2) (part 2)

[Adrian Bunk]

This email lists some known regressions in 2.6.21-rc1 compared to 2.6.20
that are not yet fixed in Linus' tree.

If you find your name in the Cc header, you are either submitter of one
of the bugs, maintainer of an affectected subsystem or driver, a patch
of you caused a breakage or I'm considering you in any other way possibly
involved with one or more of these issues.

Due to the huge amount of recipients, please trim the Cc when answering.


Subject    : forcedeth no longer works
References : http://bugzilla.kernel.org/show_bug.cgi?id=8090
Submitter  : David P. Reed <dpreed@reed.com>
Caused-By  : Ayaz Abdulla <aabdulla@nvidia.com>
Status     : unknown


Subject    : forcedeth: skb_over_panic
References : http://bugzilla.kernel.org/show_bug.cgi?id=8058
Submitter  : Albert Hopkins <kernel@marduk.letterboxes.org>
Status     : unknown


Subject    : natsemi ethernet card not detected correctly
References : http://lkml.org/lkml/2007/2/23/4
             http://lkml.org/lkml/2007/2/23/7
Submitter  : Bob Tracy <rct@gherkin.frus.com>
Caused-By  : Mark Brown <broonie@sirena.org.uk>
Handled-By : Mark Brown <broonie@sirena.org.uk>
Patch      : http://lkml.org/lkml/2007/2/23/142
Status     : patch available


Subject    : ThinkPad T60: system doesn't come out of suspend to RAM
             (CONFIG_NO_HZ)
References : http://lkml.org/lkml/2007/2/22/391
Submitter  : Michael S. Tsirkin <mst@mellanox.co.il>
Handled-By : Thomas Gleixner <tglx@linutronix.de>
             Ingo Molnar <mingo@elte.hu>
Status     : unknown


Subject    : kernel BUG at kernel/time/tick-sched.c:168  (CONFIG_NO_HZ)
References : http://lkml.org/lkml/2007/2/16/346
Submitter  : Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Handled-By : Thomas Gleixner <tglx@linutronix.de>
Status     : problem is being debugged


Subject    : BUG: soft lockup detected on CPU#0
             NOHZ: local_softirq_pending 20  (SMT scheduler)
References : http://lkml.org/lkml/2007/2/20/257
Submitter  : Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Handled-By : Thomas Gleixner <tglx@linutronix.de>
             Ingo Molnar <mingo@elte.hu>
Status     : problem is being debugged


Subject    : i386: no boot with nmi_watchdog=1  (clockevents)
References : http://lkml.org/lkml/2007/2/21/208
Submitter  : Daniel Walker <dwalker@mvista.com>
Caused-By  : Thomas Gleixner <tglx@linutronix.de>
             commit e9e2cdb412412326c4827fc78ba27f410d837e6e
Handled-By : Thomas Gleixner <tglx@linutronix.de>
Status     : problem is being debugged

Re: 2.6.21-rc1: known regressions (v2) (part 2)

[Thomas Gleixner]

Adrian,

On Mon, 2007-02-26 at 23:05 +0100, Adrian Bunk wrote:
> Subject    : kernel BUG at kernel/time/tick-sched.c:168  (CONFIG_NO_HZ)
> References : http://lkml.org/lkml/2007/2/16/346
> Submitter  : Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
> Handled-By : Thomas Gleixner <tglx@linutronix.de>
> Status     : problem is being debugged

The BUG_ON() was replaced by a warning printk(). The BUG_ON() exposed a
problem with the SMT scheduler. See below.

> Subject    : BUG: soft lockup detected on CPU#0
>              NOHZ: local_softirq_pending 20  (SMT scheduler)
> References : http://lkml.org/lkml/2007/2/20/257
> Submitter  : Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
> Handled-By : Thomas Gleixner <tglx@linutronix.de>
>              Ingo Molnar <mingo@elte.hu>
> Status     : problem is being debugged

Patch available, not confirmed yet.

	tglx

Re: 2.6.21-rc1: known regressions (v2) (part 2)

[Ingo Molnar]

* Michal Piotrowski <michal.k.k.piotrowski@gmail.com> wrote:

> Thomas Gleixner napisał(a):
> > Adrian,
> > 
> > On Mon, 2007-02-26 at 23:05 +0100, Adrian Bunk wrote:
> >> Subject    : kernel BUG at kernel/time/tick-sched.c:168  (CONFIG_NO_HZ)
> >> References : http://lkml.org/lkml/2007/2/16/346
> >> Submitter  : Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
> >> Handled-By : Thomas Gleixner <tglx@linutronix.de>
> >> Status     : problem is being debugged
> > 
> > The BUG_ON() was replaced by a warning printk(). The BUG_ON() exposed a
> > problem with the SMT scheduler. See below.
> > 
> >> Subject    : BUG: soft lockup detected on CPU#0
> >>              NOHZ: local_softirq_pending 20  (SMT scheduler)
> >> References : http://lkml.org/lkml/2007/2/20/257
> >> Submitter  : Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
> >> Handled-By : Thomas Gleixner <tglx@linutronix.de>
> >>              Ingo Molnar <mingo@elte.hu>
> >> Status     : problem is being debugged
> > 
> > Patch available, not confirmed yet.
> > 
> 
> I can confirm that the bug is fixed (over 20 hours of testing should 
> be enough).

thanks alot! I think this thing was a long-term performance/latency 
regression in HT scheduling as well.

	Ingo

Re: 2.6.21-rc1: known regressions (v2) (part 2)

[Michal Piotrowski]

Thomas Gleixner napisał(a):
> Adrian,
> 
> On Mon, 2007-02-26 at 23:05 +0100, Adrian Bunk wrote:
>> Subject    : kernel BUG at kernel/time/tick-sched.c:168  (CONFIG_NO_HZ)
>> References : http://lkml.org/lkml/2007/2/16/346
>> Submitter  : Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
>> Handled-By : Thomas Gleixner <tglx@linutronix.de>
>> Status     : problem is being debugged
> 
> The BUG_ON() was replaced by a warning printk(). The BUG_ON() exposed a
> problem with the SMT scheduler. See below.
> 
>> Subject    : BUG: soft lockup detected on CPU#0
>>              NOHZ: local_softirq_pending 20  (SMT scheduler)
>> References : http://lkml.org/lkml/2007/2/20/257
>> Submitter  : Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
>> Handled-By : Thomas Gleixner <tglx@linutronix.de>
>>              Ingo Molnar <mingo@elte.hu>
>> Status     : problem is being debugged
> 
> Patch available, not confirmed yet.
> 

I can confirm that the bug is fixed (over 20 hours of testing should be enough).

Huge thanks!

Regards,
Michal

-- 
Michal K. K. Piotrowski
LTG - Linux Testers Group (PL)
(http://www.stardust.webpages.pl/ltg/)
LTG - Linux Testers Group (EN)
(http://www.stardust.webpages.pl/linux_testers_group_en/)

Re: 2.6.21-rc1: known regressions (v2) (part 2)

[Michal Piotrowski]

Michal Piotrowski napisał(a):
> Thomas Gleixner napisał(a):
>> Adrian,
>>
>> On Mon, 2007-02-26 at 23:05 +0100, Adrian Bunk wrote:
>>> Subject    : kernel BUG at kernel/time/tick-sched.c:168  (CONFIG_NO_HZ)
>>> References : http://lkml.org/lkml/2007/2/16/346
>>> Submitter  : Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
>>> Handled-By : Thomas Gleixner <tglx@linutronix.de>
>>> Status     : problem is being debugged
>> The BUG_ON() was replaced by a warning printk(). The BUG_ON() exposed a
>> problem with the SMT scheduler. See below.
>>
>>> Subject    : BUG: soft lockup detected on CPU#0
>>>              NOHZ: local_softirq_pending 20  (SMT scheduler)
>>> References : http://lkml.org/lkml/2007/2/20/257
>>> Submitter  : Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
>>> Handled-By : Thomas Gleixner <tglx@linutronix.de>
>>>              Ingo Molnar <mingo@elte.hu>
>>> Status     : problem is being debugged
>> Patch available, not confirmed yet.
>>
> 
> I can confirm that the bug is fixed (over 20 hours of testing should be enough).
                                       ^^^^ almost ;)

Regards,
Michal

--
Michal K. K. Piotrowski
LTG - Linux Testers Group (PL)
(http://www.stardust.webpages.pl/ltg/)
LTG - Linux Testers Group (EN)
(http://www.stardust.webpages.pl/linux_testers_group_en/)

Re: 2.6.21-rc1: known regressions (v2) (part 2)

[Mike Galbraith]

On Tue, 2007-02-27 at 09:33 +0100, Ingo Molnar wrote:
> * Michal Piotrowski <michal.k.k.piotrowski@gmail.com> wrote:
> 
> > Thomas Gleixner napisał(a):
> > > Adrian,
> > > 
> > > On Mon, 2007-02-26 at 23:05 +0100, Adrian Bunk wrote:
> > >> Subject    : kernel BUG at kernel/time/tick-sched.c:168  (CONFIG_NO_HZ)
> > >> References : http://lkml.org/lkml/2007/2/16/346
> > >> Submitter  : Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
> > >> Handled-By : Thomas Gleixner <tglx@linutronix.de>
> > >> Status     : problem is being debugged
> > > 
> > > The BUG_ON() was replaced by a warning printk(). The BUG_ON() exposed a
> > > problem with the SMT scheduler. See below.
> > > 
> > >> Subject    : BUG: soft lockup detected on CPU#0
> > >>              NOHZ: local_softirq_pending 20  (SMT scheduler)
> > >> References : http://lkml.org/lkml/2007/2/20/257
> > >> Submitter  : Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
> > >> Handled-By : Thomas Gleixner <tglx@linutronix.de>
> > >>              Ingo Molnar <mingo@elte.hu>
> > >> Status     : problem is being debugged
> > > 
> > > Patch available, not confirmed yet.
> > > 
> > 
> > I can confirm that the bug is fixed (over 20 hours of testing should 
> > be enough).
> 
> thanks alot! I think this thing was a long-term performance/latency 
> regression in HT scheduling as well.

Agreed.

I was recently looking at that spot because I found that niced tasks
were taking latency hits, and disabled it, which helped a bunch.  I also
can't understand why it would be OK to interleave a normal task with an
RT task sometimes, but not others.. that's meaningless to the RT task.

IMHO, SMT scheduling should be a buyer beware thing.  Maximizing your
core utilization comes at a price, but so does disabling it, so I think
letting the user decide what he wants is the right thing to do.

	-Mike