From: Peter Zijlstra <peterz@infradead.org>
To: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
srikar@linux.vnet.ibm.com, Thomas Gleixner <tglx@linutronix.de>,
"linux-tip-commits@vger.kernel.org"
<linux-tip-commits@vger.kernel.org>
Subject: Re: [tip:sched/urgent] sched: Check sched_domain before computing group power
Date: Fri, 22 Nov 2013 13:07:33 +0100 [thread overview]
Message-ID: <20131122120733.GP3866@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <CAE9FiQUHQ7jQfpxi+s7yeef17-+ApGjU2X1iRnm=azJ0+BFWZw@mail.gmail.com>
On Thu, Nov 21, 2013 at 09:22:24AM -0800, Yinghai Lu wrote:
> On Thu, Nov 21, 2013 at 7:03 AM, Peter Zijlstra <peterz@infradead.org> wrote:
> >>
> >> This one seems fix NULL reference in compute_group_power.
> >>
> >> but get following on current Linus tree plus tip/sched/urgent.
> >>
> >> divide error: 0000 [#1] SMP
> >> [ 28.190477] Modules linked in:
> >> [ 28.192012] CPU: 11 PID: 484 Comm: kworker/u324:0 Not tainted
> >> 3.12.0-yh-10487-g4b94e59-dirty #2044
> >> [ 28.210488] Hardware name: Oracle Corporation Sun Fire
> >> [ 28.229877] task: ffff88ff25205140 ti: ffff88ff2520a000 task.ti:
> >> ffff88ff2520a000
> >> [ 28.236139] RIP: 0010:[<ffffffff810d9ff4>] [<ffffffff810d9ff4>]
> >> find_busiest_group+0x2b4/0x8a0
> >
> > Hurmph.. what kind of hardware is that? and is there anything funny you
> > do to make it do this?
>
> intel nehanem-ex or westmere-ex 8 sockets system.
>
> I tried without my local patches, the problem is still there.
And I suppose a kernel before
863bffc80898 ("sched/fair: Fix group power_orig computation")
work fine, eh?
I'll further assume that your RIP points to:
sds.avg_load = (SCHED_POWER_SCALE * sds.total_load) / sds.total_pwr;
indicating that sds.total_pwr := 0.
update_sd_lb_stats() computes it like:
sds->total_pwr += sgs->group_power;
which comes out of update_sg_lb_stats() like:
sgs->group_power = group->sgp->power;
Which we compute in update_group_power() similarly to how we did before
863bffc80898.
Which leaves me a bit puzzled.
next prev parent reply other threads:[~2013-11-22 12:07 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-12 18:05 [tip:sched/core] sched/fair: Fix group power_orig computation tip-bot for Peter Zijlstra
2013-09-12 23:21 ` Michael Neuling
2013-11-12 10:55 ` Srikar Dronamraju
2013-11-12 11:57 ` Peter Zijlstra
2013-11-12 16:41 ` [PATCH v2] sched: Check sched_domain before computing group power Srikar Dronamraju
2013-11-12 17:03 ` Peter Zijlstra
2013-11-12 17:15 ` Srikar Dronamraju
2013-11-12 17:55 ` Peter Zijlstra
2013-11-13 5:55 ` Srikar Dronamraju
[not found] ` <CAM4v1pNMn=5oZDiX3fUp9uPkZTPJgk=vEKEjevzvpwn=PjTzXg@mail.gmail.com>
2013-11-13 11:23 ` Srikar Dronamraju
2013-11-14 6:06 ` Preeti U Murthy
2013-11-14 8:30 ` Peter Zijlstra
2013-11-14 9:12 ` Preeti U Murthy
2013-11-13 15:17 ` Peter Zijlstra
2013-11-14 10:50 ` Srikar Dronamraju
2013-11-14 11:15 ` Peter Zijlstra
2013-11-19 19:15 ` [tip:sched/urgent] " tip-bot for Srikar Dronamraju
2013-11-19 23:36 ` Yinghai Lu
2013-11-21 15:03 ` Peter Zijlstra
2013-11-21 17:22 ` Yinghai Lu
2013-11-21 22:03 ` Yinghai Lu
2013-11-28 3:02 ` David Rientjes
2013-11-28 7:07 ` Yinghai Lu
2013-11-28 9:38 ` Peter Zijlstra
2013-11-28 20:23 ` Yinghai Lu
2013-12-06 6:24 ` Yinghai Lu
2013-12-10 10:58 ` Peter Zijlstra
2013-12-10 21:26 ` Yinghai Lu
2013-11-22 12:07 ` Peter Zijlstra [this message]
2013-11-23 5:00 ` Yinghai Lu
2013-11-23 18:53 ` Peter Zijlstra
2013-11-28 2:57 ` David Rientjes
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20131122120733.GP3866@twins.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=srikar@linux.vnet.ibm.com \
--cc=tglx@linutronix.de \
--cc=yinghai@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).