Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753255Ab0H0BWN (ORCPT ); Thu, 26 Aug 2010 21:22:13 -0400 Received: from mga03.intel.com ([143.182.124.21]:53846 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752255Ab0H0BWL (ORCPT ); Thu, 26 Aug 2010 21:22:11 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.56,277,1280732400"; d="scan'208";a="317679626" Date: Fri, 27 Aug 2010 09:21:47 +0800 From: Wu Fengguang To: Minchan Kim Cc: Mel Gorman , "linux-mm@kvack.org" , "linux-fsdevel@vger.kernel.org" , Andrew Morton , Christian Ehrhardt , Johannes Weiner , Jan Kara , "linux-kernel@vger.kernel.org" , Rik van Riel , KOSAKI Motohiro , KAMEZAWA Hiroyuki , Li Shaohua Subject: Re: [RFC PATCH 0/3] Do not wait the full timeout on congestion_wait when there is no congestion Message-ID: <20100827012147.GC7353@localhost> References: <1282835656-5638-1-git-send-email-mel@csn.ul.ie> <20100826172038.GA6873@barrios-desktop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100826172038.GA6873@barrios-desktop> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2075 Lines: 56 Minchan, It's much cleaner to keep the unchanged congestion_wait() and add a congestion_wait_check() for converting problematic wait sites. The too_many_isolated() wait is merely a protective mechanism, I won't bother to improve it at the cost of more code. Thanks, Fengguang > diff --git a/mm/compaction.c b/mm/compaction.c > index 94cce51..7370683 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -253,7 +253,11 @@ static unsigned long isolate_migratepages(struct zone *zone, > * delay for some time until fewer pages are isolated > */ > while (unlikely(too_many_isolated(zone))) { > - congestion_wait(BLK_RW_ASYNC, HZ/10); > + long timeout = HZ/10; > + if (timeout == congestion_wait(BLK_RW_ASYNC, timeout)) { > + set_current_state(TASK_INTERRUPTIBLE); > + schedule_timeout(timeout); > + } > > if (fatal_signal_pending(current)) > return 0; > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 3109ff7..f5e3e28 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -1337,7 +1337,11 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone, > unsigned long nr_dirty; > while (unlikely(too_many_isolated(zone, file, sc))) { > - congestion_wait(BLK_RW_ASYNC, HZ/10); > + long timeout = HZ/10; > + if (timeout == congestion_wait(BLK_RW_ASYNC, timeout)) { > + set_current_state(TASK_INTERRUPTIBLE); > + schedule_timeout(timeout); > + } > > /* We are about to die and free our memory. Return now. */ > if (fatal_signal_pending(current)) > -- > 1.7.0.5 > > > -- > Kind regards, > Minchan Kim -- 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/