From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755238AbaIDJXe (ORCPT ); Thu, 4 Sep 2014 05:23:34 -0400 Received: from ipmail05.adl6.internode.on.net ([150.101.137.143]:37744 "EHLO ipmail05.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751480AbaIDJXc (ORCPT ); Thu, 4 Sep 2014 05:23:32 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AuYrAMguCFR5LKYhPGdsb2JhbABZgw2DVoUHqAcGmkGFaQEDAQEBgQgXBQEBAQE4NoQEAQUnExwjEAgDGAklDwUlAwcaE4hBvlwBFxiFZIlRB4RMBZxrjCGMdSsvgk8BAQE Date: Thu, 4 Sep 2014 19:23:29 +1000 From: Dave Chinner To: Junxiao Bi Cc: akpm@linux-foundation.org, xuejiufei@huawei.com, ming.lei@canonical.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set Message-ID: <20140904092329.GN20473@dastard> References: <1409723694-16047-1-git-send-email-junxiao.bi@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1409723694-16047-1-git-send-email-junxiao.bi@oracle.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 03, 2014 at 01:54:54PM +0800, Junxiao Bi wrote: > commit 21caf2fc1931 ("mm: teach mm by current context info to not do I/O during memory allocation") > introduces PF_MEMALLOC_NOIO flag to avoid doing I/O inside memory allocation, __GFP_IO is cleared > when this flag is set, but __GFP_FS implies __GFP_IO, it should also be cleared. Or it may still > run into I/O, like in superblock shrinker. > > Signed-off-by: Junxiao Bi > Cc: joyce.xue > Cc: Ming Lei > --- > include/linux/sched.h | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/include/linux/sched.h b/include/linux/sched.h > index 5c2c885..2fb2c47 100644 > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -1936,11 +1936,13 @@ extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, > #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) > #define used_math() tsk_used_math(current) > > -/* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags */ > +/* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags > + * __GFP_FS is also cleared as it implies __GFP_IO. > + */ > static inline gfp_t memalloc_noio_flags(gfp_t flags) > { > if (unlikely(current->flags & PF_MEMALLOC_NOIO)) > - flags &= ~__GFP_IO; > + flags &= ~(__GFP_IO | __GFP_FS); > return flags; > } You also need to mask all the shrink_control->gfp_mask initialisations in mm/vmscan.c. The current code only masks the page reclaim gfp_mask, not those that are passed to the shrinkers. Cheers, Dave. -- Dave Chinner david@fromorbit.com