From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755465Ab1CCIR7 (ORCPT ); Thu, 3 Mar 2011 03:17:59 -0500 Received: from mga01.intel.com ([192.55.52.88]:59999 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751271Ab1CCIRz (ORCPT ); Thu, 3 Mar 2011 03:17:55 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.62,257,1297065600"; d="scan'208";a="893290339" Message-Id: <20110303074949.165618203@intel.com> User-Agent: quilt/0.48-1 Date: Thu, 03 Mar 2011 14:45:09 +0800 From: Wu Fengguang To: Andrew Morton CC: Jan Kara , Peter Zijlstra , Richard Kennedy , Wu Fengguang CC: Christoph Hellwig CC: Trond Myklebust CC: Dave Chinner CC: "Theodore Ts'o" CC: Chris Mason 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 Subject: [PATCH 04/27] writeback: reduce per-bdi dirty threshold ramp up time References: <20110303064505.718671603@intel.com> Content-Disposition: inline; filename=writeback-speedup-per-bdi-threshold-ramp-up.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Reduce the dampening for the control system, yielding faster convergence. The change is a bit conservative, as smaller values may lead to noticeable bdi threshold fluctuates in low memory JBOD setup. CC: Peter Zijlstra CC: Richard Kennedy Signed-off-by: Wu Fengguang --- mm/page-writeback.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- linux-next.orig/mm/page-writeback.c 2011-03-02 14:52:19.000000000 +0800 +++ linux-next/mm/page-writeback.c 2011-03-02 15:00:17.000000000 +0800 @@ -145,7 +145,7 @@ static int calc_period_shift(void) else dirty_total = (vm_dirty_ratio * determine_dirtyable_memory()) / 100; - return 2 + ilog2(dirty_total - 1); + return ilog2(dirty_total - 1); } /*