Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751742AbcDOM3b (ORCPT ); Fri, 15 Apr 2016 08:29:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53054 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750709AbcDOM3a (ORCPT ); Fri, 15 Apr 2016 08:29:30 -0400 Date: Fri, 15 Apr 2016 08:29:28 -0400 (EDT) From: Mikulas Patocka X-X-Sender: mpatocka@file01.intranet.prod.int.rdu2.redhat.com To: Michal Hocko cc: linux-mm@kvack.org, Andrew Morton , LKML , Michal Hocko , Shaohua Li Subject: Re: [PATCH 17/19] dm: get rid of superfluous gfp flags In-Reply-To: <1460372892-8157-18-git-send-email-mhocko@kernel.org> Message-ID: References: <1460372892-8157-1-git-send-email-mhocko@kernel.org> <1460372892-8157-18-git-send-email-mhocko@kernel.org> User-Agent: Alpine 2.02 (LRH 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Fri, 15 Apr 2016 12:29:29 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1721 Lines: 48 On Mon, 11 Apr 2016, Michal Hocko wrote: > From: Michal Hocko > > copy_params seems to be little bit confused about which allocation flags > to use. It enforces GFP_NOIO even though it uses > memalloc_noio_{save,restore} which enforces GFP_NOIO at the page memalloc_noio_{save,restore} is used because __vmalloc is flawed and doesn't respect GFP_NOIO properly (it doesn't use gfp flags when allocating pagetables). The proper fix it to correct __vmalloc (though, it would require change to pagetable allocation routine on all architectures), not to remove GFP_NOIO from __vmalloc. Mikulas > allocator level automatically (via memalloc_noio_flags). It also > uses __GFP_REPEAT for the __vmalloc request which doesn't make much > sense either because vmalloc doesn't rely on costly high order > allocations. > > Cc: Shaohua Li > Cc: Mikulas Patocka > Signed-off-by: Michal Hocko > --- > drivers/md/dm-ioctl.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c > index 2adf81d81fca..dfe629a294e1 100644 > --- a/drivers/md/dm-ioctl.c > +++ b/drivers/md/dm-ioctl.c > @@ -1723,7 +1723,7 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kern > if (!dmi) { > unsigned noio_flag; > noio_flag = memalloc_noio_save(); > - dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH | __GFP_HIGHMEM, PAGE_KERNEL); > + dmi = __vmalloc(param_kernel->data_size, __GFP_HIGH | __GFP_HIGHMEM, PAGE_KERNEL); > memalloc_noio_restore(noio_flag); > if (dmi) > *param_flags |= DM_PARAMS_VMALLOC; > -- > 2.8.0.rc3 >