From: Peter Zijlstra <peterz@infradead.org>
To: Davidlohr Bueso <davidlohr@hp.com>
Cc: tglx@linutronix.de, mingo@kernel.org, dvhart@linux.intel.com,
paulmck@linux.vnet.ibm.com, torvalds@linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: futex funkiness -- massive lockups
Date: Wed, 5 Mar 2014 09:16:44 +0100 [thread overview]
Message-ID: <20140305081644.GR9987@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <1393983784.2512.40.camel@buesod1.americas.hpqcorp.net>
On Tue, Mar 04, 2014 at 05:43:04PM -0800, Davidlohr Bueso wrote:
> Hi,
>
> A large amount of lockups are seen on a 480 core system doing some sort
> of database-like workload. All except one are soft lockups. This is a
> SLES11 system with most of the recent futex changes backported,
> including commits 63b1a816, b0c29f79, 99b60ce6, a52b89eb, 0d00c7b2,
> 5cdec2d8 and f12d5bfc.
>
> [212071.494920] [<ffffffff810589e5>] load_balance+0xa5/0x470
> [212071.494920] [<ffffffff81058f13>] rebalance_domains+0x163/0x220
> [212071.494920] [<ffffffff81059144>] run_rebalance_domains+0x44/0x60
> [212071.494920] [<ffffffff810677df>] __do_softirq+0x11f/0x260
> [212071.494920] [<ffffffff81469fdc>] call_softirq+0x1c/0x30
> [212071.494920] [<ffffffff81004435>] do_softirq+0x65/0xa0
> [212071.494920] [<ffffffff810675a5>] irq_exit+0xc5/0xe0
> [212071.494920] [<ffffffff81026588>] smp_apic_timer_interrupt+0x68/0xa0
> [212071.494920] [<ffffffff81469773>] apic_timer_interrupt+0x13/0x20
> [212071.494920] [<ffffffff81460ec5>] _raw_spin_lock+0x15/0x20
> [212071.494920] [<ffffffff8109626a>] futex_wake+0xba/0x180
> [212071.494920] [<ffffffff810987c4>] do_futex+0x94/0x1c0
> [212071.494920] [<ffffffff81098972>] sys_futex+0x82/0x170
> [212071.494920] [<ffffffff81468d92>] system_call_fastpath+0x16/0x1b
>
Like Linus said; that looks like its stuck in the load balancer. Now 480
is certainly more CPUs that usual. However, SGI ran with lots more and I
don't recall them seeing soft lockups from this.
OTOH I do know the softirq runs for more than a softirq should; even on
moderate systems.
next prev parent reply other threads:[~2014-03-05 8:17 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-05 1:43 futex funkiness -- massive lockups Davidlohr Bueso
2014-03-05 3:36 ` Linus Torvalds
2014-03-05 4:45 ` Davidlohr Bueso
2014-03-05 8:16 ` Peter Zijlstra [this message]
2014-03-05 9:01 ` Ingo Molnar
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=20140305081644.GR9987@twins.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=davidlohr@hp.com \
--cc=dvhart@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=paulmck@linux.vnet.ibm.com \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.