Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758768AbZLNXJH (ORCPT ); Mon, 14 Dec 2009 18:09:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758741AbZLNXJB (ORCPT ); Mon, 14 Dec 2009 18:09:01 -0500 Received: from mail-yw0-f182.google.com ([209.85.211.182]:34192 "EHLO mail-yw0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758749AbZLNXJA (ORCPT ); Mon, 14 Dec 2009 18:09:00 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:in-reply-to:references:x-mailer :mime-version:content-type:content-transfer-encoding; b=r4XdYA5JDXd16IOV6e/rzHy+jlq99ZQyigr7Ped/uxEk6G+PU1ofgaszfHPdP45kBw ukkyNi51+RAN2Kzk5Zg7LK3Bz/fOJHzKxGyJAtmq5/Tec/D1UCtWHohz88+ssIQ+dBjt 9cCPXcoXFYV3CF3p6HLY+sulZmFaOXDxvDPQo= Date: Tue, 15 Dec 2009 08:03:28 +0900 From: Minchan Kim To: KOSAKI Motohiro Cc: Rik van Riel , lwoodman@redhat.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, minchan.kim@gmail.com Subject: Re: [PATCH 4/8] Use prepare_to_wait_exclusive() instead prepare_to_wait() Message-Id: <20091215080328.b4af59ad.minchan.kim@barrios-desktop> In-Reply-To: <20091214212936.BBBA.A69D9226@jp.fujitsu.com> References: <20091211164651.036f5340@annuminas.surriel.com> <20091214210823.BBAE.A69D9226@jp.fujitsu.com> <20091214212936.BBBA.A69D9226@jp.fujitsu.com> X-Mailer: Sylpheed 2.6.0 (GTK+ 2.16.1; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1530 Lines: 44 On Mon, 14 Dec 2009 21:30:19 +0900 (JST) KOSAKI Motohiro wrote: > if we don't use exclusive queue, wake_up() function wake _all_ waited > task. This is simply cpu wasting. > > Signed-off-by: KOSAKI Motohiro > --- > mm/vmscan.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index e0cb834..3562a2d 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -1618,7 +1618,7 @@ static int shrink_zone_begin(struct zone *zone, struct scan_control *sc) > * we would just make things slower. > */ > for (;;) { > - prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); > + prepare_to_wait_exclusive(wq, &wait, TASK_UNINTERRUPTIBLE); > > if (atomic_read(&zone->concurrent_reclaimers) <= > max_zone_concurrent_reclaimers) > @@ -1632,7 +1632,7 @@ static int shrink_zone_begin(struct zone *zone, struct scan_control *sc) > */ > if (zone_watermark_ok(zone, sc->order, low_wmark_pages(zone), > 0, 0)) { > - wake_up(wq); > + wake_up_all(wq); I think it's typo. The description in changelog says we want "wake_up". Otherwise, looks good to me. Reviewed-by: Minchan Kim -- 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/