From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758947AbZBYCgx (ORCPT ); Tue, 24 Feb 2009 21:36:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754321AbZBYCgn (ORCPT ); Tue, 24 Feb 2009 21:36:43 -0500 Received: from cmpxchg.org ([85.214.51.133]:38561 "EHLO cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754086AbZBYCgm (ORCPT ); Tue, 24 Feb 2009 21:36:42 -0500 Date: Wed, 25 Feb 2009 03:38:30 +0100 From: Johannes Weiner To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [patch] mm: move pagevec stripping to save unlock-relock Message-ID: <20090225023830.GA1611@cmpxchg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In shrink_active_list() after the deactivation loop, we strip buffer heads from the potentially remaining pages in the pagevec. Currently, this drops the zone's lru lock for stripping, only to reacquire it again afterwards to update statistics. It is not necessary to strip the pages before updating the stats, so move the whole thing out of the protected region and save the extra locking. Signed-off-by: Johannes Weiner --- mm/vmscan.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1298,14 +1298,11 @@ static void shrink_active_list(unsigned } __mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved); pgdeactivate += pgmoved; - if (buffer_heads_over_limit) { - spin_unlock_irq(&zone->lru_lock); - pagevec_strip(&pvec); - spin_lock_irq(&zone->lru_lock); - } __count_zone_vm_events(PGREFILL, zone, pgscanned); __count_vm_events(PGDEACTIVATE, pgdeactivate); spin_unlock_irq(&zone->lru_lock); + if (buffer_heads_over_limit) + pagevec_strip(&pvec); if (vm_swap_full()) pagevec_swap_free(&pvec);