From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id p8KEEK8Z064833 for ; Tue, 20 Sep 2011 09:14:20 -0500 Received: from mx1.redhat.com (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id D702914025E5 for ; Tue, 20 Sep 2011 07:19:37 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id Sajoc6u9McAyE56h for ; Tue, 20 Sep 2011 07:19:37 -0700 (PDT) Date: Tue, 20 Sep 2011 16:14:03 +0200 From: Johannes Weiner Subject: Re: [patch 4/4] Btrfs: pass __GFP_WRITE for buffered write page allocations Message-ID: <20110920141403.GA17198@redhat.com> References: <1316526315-16801-1-git-send-email-jweiner@redhat.com> <1316526315-16801-5-git-send-email-jweiner@redhat.com> <20110920135631.GB16338@redhat.com> <4E789EA2.8070709@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <4E789EA2.8070709@redhat.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Josef Bacik Cc: Rik van Riel , linux-ext4@vger.kernel.org, Jan Kara , linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, xfs@oss.sgi.com, Christoph Hellwig , linux-mm@kvack.org, Andreas Dilger , Mel Gorman , linux-fsdevel@vger.kernel.org, Theodore Ts'o , Andrew Morton , Wu Fengguang , Chris Mason , Minchan Kim On Tue, Sep 20, 2011 at 10:09:38AM -0400, Josef Bacik wrote: > On 09/20/2011 09:56 AM, Johannes Weiner wrote: > > On Tue, Sep 20, 2011 at 03:45:15PM +0200, Johannes Weiner wrote: > >> Tell the page allocator that pages allocated for a buffered write are > >> expected to become dirty soon. > >> > >> Signed-off-by: Johannes Weiner > >> --- > >> fs/btrfs/file.c | 2 +- > >> 1 files changed, 1 insertions(+), 1 deletions(-) > >> > >> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c > >> index e7872e4..ea1b892 100644 > >> --- a/fs/btrfs/file.c > >> +++ b/fs/btrfs/file.c > >> @@ -1084,7 +1084,7 @@ static noinline int prepare_pages(struct btrfs_root *root, struct file *file, > >> again: > >> for (i = 0; i < num_pages; i++) { > >> pages[i] = find_or_create_page(inode->i_mapping, index + i, > >> - GFP_NOFS); > >> + GFP_NOFS | __GFP_WRITE); > > > > Btw and unrelated to this particular series, I think this should use > > grab_cache_page_write_begin() in the first place. > > > > Most grab_cache_page calls were replaced recently (a94733d "Btrfs: use > > find_or_create_page instead of grab_cache_page") to be able to pass > > GFP_NOFS, but the pages are now also no longer __GFP_HIGHMEM and > > __GFP_MOVABLE, which irks both x86_32 and memory hotplug. > > > > It might be better to change grab_cache_page instead to take a flags > > argument that allows passing AOP_FLAG_NOFS and revert the sites back > > to this helper? > > So I can do > > pages[i] = grab_cache_page_write_begin(inode->i_mapping, index + i, > AOP_FLAG_NOFS); > > right? All we need is nofs, so I can just go through and change > everybody to that. It does wait_on_page_writeback() in addition, so it may not be appropriate for every callsite, I haven't checked. But everything that grabs a page for writing should be fine if you do it like this. > I'd rather not have to go through and change grab_cache_page() to > take a flags argument and change all the callers, I have a bad habit > of screwing stuff like that up :). Yeah, there are quite a few. If we can get around it, all the better. Hannes _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs