From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753125AbdBAR6K (ORCPT ); Wed, 1 Feb 2017 12:58:10 -0500 Received: from mx2.suse.de ([195.135.220.15]:60477 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750777AbdBAR6J (ORCPT ); Wed, 1 Feb 2017 12:58:09 -0500 Date: Wed, 1 Feb 2017 18:58:03 +0100 From: Michal Hocko To: Mikulas Patocka Cc: Andrew Morton , Vlastimil Babka , David Rientjes , Mel Gorman , Johannes Weiner , Al Viro , linux-mm@kvack.org, LKML , Mike Snitzer Subject: Re: [PATCH 7/9] md: use kvmalloc rather than opencoded variant Message-ID: <20170201175802.GA9839@dhcp22.suse.cz> References: <20170130094940.13546-1-mhocko@kernel.org> <20170130094940.13546-8-mhocko@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 01-02-17 12:29:56, Mikulas Patocka wrote: > > > On Mon, 30 Jan 2017, Michal Hocko wrote: > > > From: Michal Hocko > > > > copy_params uses kmalloc with vmalloc fallback. We already have a helper > > for that - kvmalloc. This caller requires GFP_NOIO semantic so it hasn't > > been converted with many others by previous patches. All we need to > > achieve this semantic is to use the scope memalloc_noio_{save,restore} > > around kvmalloc. > > > > Cc: Mikulas Patocka > > Cc: Mike Snitzer > > Signed-off-by: Michal Hocko > > --- > > drivers/md/dm-ioctl.c | 13 ++++--------- > > 1 file changed, 4 insertions(+), 9 deletions(-) > > > > diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c > > index a5a9b17f0f7f..dbf5b981f7d7 100644 > > --- a/drivers/md/dm-ioctl.c > > +++ b/drivers/md/dm-ioctl.c > > @@ -1698,6 +1698,7 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kern > > struct dm_ioctl *dmi; > > int secure_data; > > const size_t minimum_data_size = offsetof(struct dm_ioctl, data); > > + unsigned noio_flag; > > > > if (copy_from_user(param_kernel, user, minimum_data_size)) > > return -EFAULT; > > @@ -1720,15 +1721,9 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kern > > * Use kmalloc() rather than vmalloc() when we can. > > */ > > dmi = NULL; > > - if (param_kernel->data_size <= KMALLOC_MAX_SIZE) > > - dmi = kmalloc(param_kernel->data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); > > - > > - if (!dmi) { > > - unsigned noio_flag; > > - noio_flag = memalloc_noio_save(); > > - dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_HIGH | __GFP_HIGHMEM, PAGE_KERNEL); > > - memalloc_noio_restore(noio_flag); > > - } > > + noio_flag = memalloc_noio_save(); > > + dmi = kvmalloc(param_kernel->data_size, GFP_KERNEL); > > + memalloc_noio_restore(noio_flag); > > > > if (!dmi) { > > if (secure_data && clear_user(user, param_kernel->data_size)) > > -- > > 2.11.0 > > I would push these memalloc_noio_save/memalloc_noio_restore calls to > kvmalloc, so that the othe callers can use them too. > > Something like > if ((flags & (__GFP_IO | __GFP_FS)) != (__GFP_IO | __GFP_FS)) > noio_flag = memalloc_noio_save(); > ptr = __vmalloc_node_flags(size, node, flags); > if ((flags & (__GFP_IO | __GFP_FS)) != (__GFP_IO | __GFP_FS)) > memalloc_noio_restore(noio_flag) > > Or perhaps even better - push memalloc_noio_save/memalloc_noio_restore > directly to __vmalloc, so that __vmalloc respects the gfp flags properly - > note that there are 14 places in the kernel where __vmalloc is called with > GFP_NOFS and they are all buggy because __vmalloc doesn't respect the > GFP_NOFS flag. That is out of scope of this patch series. I would like to deal with NOIO an NOFS contexts separately. -- Michal Hocko SUSE Labs From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wj0-f199.google.com (mail-wj0-f199.google.com [209.85.210.199]) by kanga.kvack.org (Postfix) with ESMTP id 507976B0038 for ; Wed, 1 Feb 2017 12:58:10 -0500 (EST) Received: by mail-wj0-f199.google.com with SMTP id gt1so79825065wjc.0 for ; Wed, 01 Feb 2017 09:58:10 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id r20si25575329wrc.97.2017.02.01.09.58.08 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 01 Feb 2017 09:58:08 -0800 (PST) Date: Wed, 1 Feb 2017 18:58:03 +0100 From: Michal Hocko Subject: Re: [PATCH 7/9] md: use kvmalloc rather than opencoded variant Message-ID: <20170201175802.GA9839@dhcp22.suse.cz> References: <20170130094940.13546-1-mhocko@kernel.org> <20170130094940.13546-8-mhocko@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Mikulas Patocka Cc: Andrew Morton , Vlastimil Babka , David Rientjes , Mel Gorman , Johannes Weiner , Al Viro , linux-mm@kvack.org, LKML , Mike Snitzer On Wed 01-02-17 12:29:56, Mikulas Patocka wrote: > > > On Mon, 30 Jan 2017, Michal Hocko wrote: > > > From: Michal Hocko > > > > copy_params uses kmalloc with vmalloc fallback. We already have a helper > > for that - kvmalloc. This caller requires GFP_NOIO semantic so it hasn't > > been converted with many others by previous patches. All we need to > > achieve this semantic is to use the scope memalloc_noio_{save,restore} > > around kvmalloc. > > > > Cc: Mikulas Patocka > > Cc: Mike Snitzer > > Signed-off-by: Michal Hocko > > --- > > drivers/md/dm-ioctl.c | 13 ++++--------- > > 1 file changed, 4 insertions(+), 9 deletions(-) > > > > diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c > > index a5a9b17f0f7f..dbf5b981f7d7 100644 > > --- a/drivers/md/dm-ioctl.c > > +++ b/drivers/md/dm-ioctl.c > > @@ -1698,6 +1698,7 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kern > > struct dm_ioctl *dmi; > > int secure_data; > > const size_t minimum_data_size = offsetof(struct dm_ioctl, data); > > + unsigned noio_flag; > > > > if (copy_from_user(param_kernel, user, minimum_data_size)) > > return -EFAULT; > > @@ -1720,15 +1721,9 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kern > > * Use kmalloc() rather than vmalloc() when we can. > > */ > > dmi = NULL; > > - if (param_kernel->data_size <= KMALLOC_MAX_SIZE) > > - dmi = kmalloc(param_kernel->data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); > > - > > - if (!dmi) { > > - unsigned noio_flag; > > - noio_flag = memalloc_noio_save(); > > - dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_HIGH | __GFP_HIGHMEM, PAGE_KERNEL); > > - memalloc_noio_restore(noio_flag); > > - } > > + noio_flag = memalloc_noio_save(); > > + dmi = kvmalloc(param_kernel->data_size, GFP_KERNEL); > > + memalloc_noio_restore(noio_flag); > > > > if (!dmi) { > > if (secure_data && clear_user(user, param_kernel->data_size)) > > -- > > 2.11.0 > > I would push these memalloc_noio_save/memalloc_noio_restore calls to > kvmalloc, so that the othe callers can use them too. > > Something like > if ((flags & (__GFP_IO | __GFP_FS)) != (__GFP_IO | __GFP_FS)) > noio_flag = memalloc_noio_save(); > ptr = __vmalloc_node_flags(size, node, flags); > if ((flags & (__GFP_IO | __GFP_FS)) != (__GFP_IO | __GFP_FS)) > memalloc_noio_restore(noio_flag) > > Or perhaps even better - push memalloc_noio_save/memalloc_noio_restore > directly to __vmalloc, so that __vmalloc respects the gfp flags properly - > note that there are 14 places in the kernel where __vmalloc is called with > GFP_NOFS and they are all buggy because __vmalloc doesn't respect the > GFP_NOFS flag. That is out of scope of this patch series. I would like to deal with NOIO an NOFS contexts separately. -- Michal Hocko SUSE Labs -- 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