From: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
To: David Rientjes <rientjes@google.com>
Cc: Dave Jones <davej@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
KOSAKI Motohiro <kosaki.motohiro@gmail.com>,
bhutchings@solarflare.com,
Konstantin Khlebnikov <khlebnikov@openvz.org>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
Hugh Dickins <hughd@google.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [patch for-3.7] mm, mempolicy: fix printing stack contents in numa_maps
Date: Wed, 17 Oct 2012 14:42:09 +0900 [thread overview]
Message-ID: <507E4531.1070700@jp.fujitsu.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1210162222100.26279@chino.kir.corp.google.com>
(2012/10/17 14:24), David Rientjes wrote:
> On Wed, 17 Oct 2012, Dave Jones wrote:
>
>> BUG: sleeping function called from invalid context at kernel/mutex.c:269
>> in_atomic(): 1, irqs_disabled(): 0, pid: 8558, name: trinity-child2
>> 3 locks on stack by trinity-child2/8558:
>> #0: held: (&p->lock){+.+.+.}, instance: ffff88010c9a00b0, at: [<ffffffff8120cd1f>] seq_lseek+0x3f/0x120
>> #1: held: (&mm->mmap_sem){++++++}, instance: ffff88013956f7c8, at: [<ffffffff81254437>] m_start+0xa7/0x190
>> #2: held: (&(&p->alloc_lock)->rlock){+.+...}, instance: ffff88011fc64f30, at: [<ffffffff81254f8f>] show_numa_map+0x14f/0x610
>> Pid: 8558, comm: trinity-child2 Not tainted 3.7.0-rc1+ #32
>> Call Trace:
>> [<ffffffff810ae4ec>] __might_sleep+0x14c/0x200
>> [<ffffffff816bdf4e>] mutex_lock_nested+0x2e/0x50
>> [<ffffffff811c43a3>] mpol_shared_policy_lookup+0x33/0x90
>> [<ffffffff8118d5c3>] shmem_get_policy+0x33/0x40
>> [<ffffffff811c31fa>] get_vma_policy+0x3a/0x90
>> [<ffffffff81254fa3>] show_numa_map+0x163/0x610
>> [<ffffffff81255b10>] ? pid_maps_open+0x20/0x20
>> [<ffffffff81255980>] ? pagemap_hugetlb_range+0xf0/0xf0
>> [<ffffffff81255483>] show_pid_numa_map+0x13/0x20
>> [<ffffffff8120c902>] traverse+0xf2/0x230
>> [<ffffffff8120cd8b>] seq_lseek+0xab/0x120
>> [<ffffffff811e6c0b>] sys_lseek+0x7b/0xb0
>> [<ffffffff816ca088>] tracesys+0xe1/0xe6
>>
>
> Hmm, looks like we need to change the refcount semantics entirely. We'll
> need to make get_vma_policy() always take a reference and then drop it
> accordingly. This work sif get_vma_policy() can grab a reference while
> holding task_lock() for the task policy fallback case.
>
> Comments on this approach?
I think this refcounting is better than using task_lock().
Thanks,
-Kame
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next prev parent reply other threads:[~2012-10-17 5:43 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-08 15:09 mpol_to_str revisited Dave Jones
2012-10-08 15:15 ` Dave Jones
2012-10-08 20:46 ` David Rientjes
2012-10-08 20:35 ` David Rientjes
2012-10-08 20:52 ` Dave Jones
2012-10-16 0:48 ` David Rientjes
2012-10-09 0:33 ` Ben Hutchings
2012-10-16 2:34 ` KOSAKI Motohiro
2012-10-16 3:58 ` David Rientjes
2012-10-16 5:10 ` KOSAKI Motohiro
2012-10-16 6:10 ` David Rientjes
2012-10-16 23:39 ` KOSAKI Motohiro
2012-10-17 0:12 ` David Rientjes
2012-10-17 0:31 ` [patch for-3.7] mm, mempolicy: fix printing stack contents in numa_maps David Rientjes
2012-10-17 1:38 ` KOSAKI Motohiro
2012-10-17 1:49 ` David Rientjes
2012-10-17 1:53 ` KOSAKI Motohiro
2012-10-17 4:05 ` Dave Jones
2012-10-17 5:24 ` David Rientjes
2012-10-17 5:42 ` Kamezawa Hiroyuki [this message]
2012-10-17 8:49 ` KOSAKI Motohiro
2012-10-17 19:50 ` David Rientjes
2012-10-17 21:05 ` KOSAKI Motohiro
2012-10-17 21:27 ` David Rientjes
2012-10-17 18:14 ` Dave Jones
2012-10-17 19:21 ` David Rientjes
2012-10-17 19:32 ` Dave Jones
2012-10-17 19:38 ` David Rientjes
2012-10-17 19:45 ` Dave Jones
2012-10-17 20:28 ` [patch for-3.7] mm, mempolicy: avoid taking mutex inside spinlock when reading numa_maps David Rientjes
2012-10-17 21:31 ` [patch for-3.7 v2] " David Rientjes
2012-10-18 4:06 ` Kamezawa Hiroyuki
2012-10-18 4:14 ` Linus Torvalds
2012-10-18 4:41 ` Kamezawa Hiroyuki
2012-10-18 4:34 ` Kamezawa Hiroyuki
2012-10-18 20:03 ` David Rientjes
2012-10-19 8:35 ` [patch for-3.7 v3] mm, mempolicy: hold task->mempolicy refcount while " Kamezawa Hiroyuki
2012-10-19 9:28 ` David Rientjes
2012-10-22 2:47 ` Kamezawa Hiroyuki
2012-10-22 20:55 ` Andrew Morton
2012-10-22 20:56 ` David Rientjes
2012-10-19 19:15 ` KOSAKI Motohiro
2012-10-19 6:51 ` [patch for-3.7 v2] mm, mempolicy: avoid taking mutex inside spinlock when " KOSAKI Motohiro
2012-10-18 4:35 ` David Rientjes
2012-10-24 23:30 ` [patch for-3.7] mm, mempolicy: fix printing stack contents in numa_maps Sasha Levin
2012-10-24 23:34 ` David Rientjes
2012-10-24 23:37 ` Sasha Levin
2012-10-25 0:08 ` David Rientjes
2012-10-25 0:54 ` KOSAKI Motohiro
2012-10-25 1:15 ` David Rientjes
2012-10-25 12:19 ` Peter Zijlstra
2012-10-25 14:39 ` Peter Zijlstra
2012-10-25 17:23 ` Sasha Levin
2012-10-25 20:22 ` David Rientjes
2012-10-25 23:09 ` Linus Torvalds
2012-10-26 8:48 ` Peter Zijlstra
2012-10-31 18:29 ` Sasha Levin
2012-11-21 0:59 ` Sasha Levin
2012-10-17 1:33 ` mpol_to_str revisited KOSAKI Motohiro
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