From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f178.google.com (mail-ob0-f178.google.com [209.85.214.178]) by kanga.kvack.org (Postfix) with ESMTP id 355FB6B003A for ; Tue, 25 Mar 2014 12:52:04 -0400 (EDT) Received: by mail-ob0-f178.google.com with SMTP id wp18so878923obc.37 for ; Tue, 25 Mar 2014 09:52:03 -0700 (PDT) Received: from qmta15.emeryville.ca.mail.comcast.net (qmta15.emeryville.ca.mail.comcast.net. [2001:558:fe2d:44:76:96:27:228]) by mx.google.com with ESMTP id z8si22809166oex.128.2014.03.25.09.52.01 for ; Tue, 25 Mar 2014 09:52:02 -0700 (PDT) Date: Tue, 25 Mar 2014 11:51:59 -0500 (CDT) From: Christoph Lameter Subject: Re: mm: slub: gpf in deactivate_slab In-Reply-To: <5331A6C3.2000303@oracle.com> Message-ID: References: <53208A87.2040907@oracle.com> <5331A6C3.2000303@oracle.com> Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Sasha Levin Cc: Pekka Enberg , Matt Mackall , "linux-mm@kvack.org" , LKML On Tue, 25 Mar 2014, Sasha Levin wrote: > I have a lead on this. Consider the following: > > kmem_cache_alloc > __slab_alloc > local_irq_save() > deactivate_slab > __cmpxchg_double_slab > slab_unlock > __bit_spin_unlock > preempt_enable > [ Page Fault ] > > With this trace, it manifests as a "BUG: sleeping function called from invalid > context at arch/x86/mm/fault.c" on a might_sleep() in the page fault handler > (which is an issue on it's own), but I suspect it's also the cause of the > trace > above - preemption enabled and a race that removed the page. > > Could someone confirm please? The preempt count is incremented earlier in bit_spin_lock so the preempt_enable() should not do anything. -- 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