From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx153.postini.com [74.125.245.153]) by kanga.kvack.org (Postfix) with SMTP id 141EC6B0068 for ; Wed, 24 Oct 2012 19:30:50 -0400 (EDT) Received: by mail-ia0-f169.google.com with SMTP id h37so1068672iak.14 for ; Wed, 24 Oct 2012 16:30:49 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <20121008150949.GA15130@redhat.com> <20121017040515.GA13505@redhat.com> From: Sasha Levin Date: Wed, 24 Oct 2012 19:30:29 -0400 Message-ID: Subject: Re: [patch for-3.7] mm, mempolicy: fix printing stack contents in numa_maps Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: Dave Jones , Andrew Morton , Linus Torvalds , KOSAKI Motohiro , bhutchings@solarflare.com, Konstantin Khlebnikov , Naoya Horiguchi , Hugh Dickins , KAMEZAWA Hiroyuki , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Wed, Oct 17, 2012 at 1:24 AM, 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: [] seq_lseek+0x3f/0x120 >> #1: held: (&mm->mmap_sem){++++++}, instance: ffff88013956f7c8, at: [] m_start+0xa7/0x190 >> #2: held: (&(&p->alloc_lock)->rlock){+.+...}, instance: ffff88011fc64f30, at: [] show_numa_map+0x14f/0x610 >> Pid: 8558, comm: trinity-child2 Not tainted 3.7.0-rc1+ #32 >> Call Trace: >> [] __might_sleep+0x14c/0x200 >> [] mutex_lock_nested+0x2e/0x50 >> [] mpol_shared_policy_lookup+0x33/0x90 >> [] shmem_get_policy+0x33/0x40 >> [] get_vma_policy+0x3a/0x90 >> [] show_numa_map+0x163/0x610 >> [] ? pid_maps_open+0x20/0x20 >> [] ? pagemap_hugetlb_range+0xf0/0xf0 >> [] show_pid_numa_map+0x13/0x20 >> [] traverse+0xf2/0x230 >> [] seq_lseek+0xab/0x120 >> [] sys_lseek+0x7b/0xb0 >> [] 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? > --- [snip] I'm not sure about the status of the patch, but it doesn't apply on top of -next, and I still see the warnings when fuzzing on -next. Thanks, Sasha -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org