From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vc0-f182.google.com (mail-vc0-f182.google.com [209.85.220.182]) by kanga.kvack.org (Postfix) with ESMTP id 38D486B0035 for ; Wed, 3 Sep 2014 08:20:36 -0400 (EDT) Received: by mail-vc0-f182.google.com with SMTP id im17so8568876vcb.41 for ; Wed, 03 Sep 2014 05:20:36 -0700 (PDT) Received: from mail-vc0-f172.google.com (mail-vc0-f172.google.com [209.85.220.172]) by mx.google.com with ESMTPS id ts8si798091vdc.34.2014.09.03.05.20.35 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 03 Sep 2014 05:20:35 -0700 (PDT) Received: by mail-vc0-f172.google.com with SMTP id ij19so8671675vcb.17 for ; Wed, 03 Sep 2014 05:20:35 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1409723694-16047-1-git-send-email-junxiao.bi@oracle.com> References: <1409723694-16047-1-git-send-email-junxiao.bi@oracle.com> Date: Wed, 3 Sep 2014 08:20:35 -0400 Message-ID: Subject: Re: [PATCH] mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set From: Trond Myklebust Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Junxiao Bi Cc: david@fromorbit.com, akpm@linux-foundation.org, xuejiufei@huawei.com, ming.lei@canonical.com, Linux Kernel mailing list , linux-mm@kvack.org, Devel FS Linux On Wed, Sep 3, 2014 at 1:54 AM, 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; > } > Shouldn't this be a stable fix? If it is needed, then it will affect all kernels that define PF_MEMALLOC_NOIO. -- Trond Myklebust Linux NFS client maintainer, PrimaryData trond.myklebust@primarydata.com -- 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