From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: [PATCH 10/27] nfs: limit the commit size to reduce fluctuations Date: Thu, 03 Mar 2011 14:45:15 +0800 Message-ID: <20110303074949.935848193@intel.com> References: <20110303064505.718671603@intel.com> Cc: Jan Kara , Trond Myklebust , Wu Fengguang To: Andrew Morton Return-path: CC: Christoph Hellwig CC: Dave Chinner CC: Theodore Ts'o CC: Chris Mason CC: Peter Zijlstra CC: Mel Gorman CC: Rik van Riel CC: KOSAKI Motohiro CC: Greg Thelen CC: Minchan Kim CC: Vivek Goyal CC: Andrea Righi CC: Balbir Singh Cc: linux-mm Cc: Cc: LKML Content-Disposition: inline; filename=nfs-more-smooth-commit.patch Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org Limit the commit size to 1/8 dirty control scope, so that the arrival of one commit will not knock the overall dirty pages off the scope. CC: Trond Myklebust Signed-off-by: Wu Fengguang --- fs/nfs/write.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) After patch, there are still drop offs from the control scope, http://www.kernel.org/pub/linux/kernel/people/wfg/writeback/dirty-throttling-v6/NFS/nfs-1dd-1M-8p-2945M-20%25-2.6.38-rc6-dt6+-2011-02-22-21-09/balance_dirty_pages-pages.png due to bursty arrival of commits: http://www.kernel.org/pub/linux/kernel/people/wfg/writeback/dirty-throttling-v6/NFS/nfs-1dd-1M-8p-2945M-20%25-2.6.38-rc6-dt6+-2011-02-22-21-09/nfs-commit.png --- linux-next.orig/fs/nfs/write.c 2011-03-02 20:39:01.000000000 +0800 +++ linux-next/fs/nfs/write.c 2011-03-02 20:39:01.000000000 +0800 @@ -1492,9 +1492,10 @@ static int nfs_commit_unstable_pages(str if (wbc->sync_mode == WB_SYNC_NONE) { /* Don't commit yet if this is a non-blocking flush and there - * are a lot of outstanding writes for this mapping. + * are a lot of outstanding writes for this mapping, until + * collected enough pages to commit. */ - if (nfsi->ncommit <= (nfsi->npages >> 1)) + if (nfsi->ncommit <= nfsi->npages / 32 /* DIRTY_MARGIN */) goto out_mark_dirty; /* don't wait for the COMMIT response */ -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org