From: Dave Jones <davej@redhat.com>
To: Linux Kernel <linux-kernel@vger.kernel.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>,
Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: sched_debug / traverse allocation failures.
Date: Tue, 6 Nov 2012 15:49:47 -0500 [thread overview]
Message-ID: <20121106204947.GA1762@redhat.com> (raw)
While fuzz-testing, I frequently run into this..
trinity-child4: page allocation failure: order:4, mode:0x40d0
Pid: 21842, comm: trinity-child4 Not tainted 3.7.0-rc4+ #54
Call Trace:
[<ffffffff81179ce9>] warn_alloc_failed+0xe9/0x150
[<ffffffff816c24fc>] ? __alloc_pages_direct_compact+0x1f8/0x209
[<ffffffff8117e6f6>] __alloc_pages_nodemask+0x936/0xb60
[<ffffffff811c2020>] alloc_pages_current+0xb0/0x120
[<ffffffff81178ada>] __get_free_pages+0x2a/0x80
[<ffffffff811ce299>] kmalloc_order_trace+0x39/0x190
[<ffffffff811ce66d>] __kmalloc+0x27d/0x2b0
[<ffffffff8120cc8d>] traverse+0x1bd/0x230
[<ffffffff8120d0c0>] ? seq_lseek+0x120/0x120
[<ffffffff8120d0c0>] ? seq_lseek+0x120/0x120
[<ffffffff8120d41b>] seq_read+0x35b/0x3e0
[<ffffffff816d1969>] ? sub_preempt_count+0x79/0xd0
[<ffffffff8120d0c0>] ? seq_lseek+0x120/0x120
[<ffffffff81257890>] proc_reg_read+0x80/0xc0
[<ffffffff811e72dc>] vfs_read+0xac/0x180
[<ffffffff811e758a>] sys_pread64+0x9a/0xb0
[<ffffffff816d5f88>] tracesys+0xe1/0xe6
I added some instrumentation to traverse, and it appears that the /proc file
in question is 'sched_debug'.
Most the time this is quite small, but can grow to large lengths it seems,
which when we're under memory fragmentation results in the spew above.
>From my reading of the code, it doesn't actually use the seq_operations,
to print out things record-at-a-time, but just dumps everything
in its ->open routine.
thoughts?
Dave
next reply other threads:[~2012-11-06 20:49 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-06 20:49 Dave Jones [this message]
2012-11-06 22:33 ` sched_debug / traverse allocation failures Al Viro
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