Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758031Ab1DMJH0 (ORCPT ); Wed, 13 Apr 2011 05:07:26 -0400 Received: from mga11.intel.com ([192.55.52.93]:43854 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757994Ab1DMJHK (ORCPT ); Wed, 13 Apr 2011 05:07:10 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.64,203,1301900400"; d="scan'208";a="908938847" Message-Id: <20110413090415.763161169@intel.com> User-Agent: quilt/0.48-1 Date: Wed, 13 Apr 2011 16:59:41 +0800 From: Wu Fengguang To: Andrew Morton cc: Peter Zijlstra , Richard Kennedy , Wu Fengguang cc: Jan Kara cc: Hugh Dickins , Rik van Riel cc: Dave Chinner Cc: LKML cc: Linux Memory Management List , Subject: [PATCH 4/4] writeback: reduce per-bdi dirty threshold ramp up time References: <20110413085937.981293444@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 Content-Length: 1039 Lines: 23 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); } /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/