Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755270AbZINLKU (ORCPT ); Mon, 14 Sep 2009 07:10:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752425AbZINLKT (ORCPT ); Mon, 14 Sep 2009 07:10:19 -0400 Received: from mail-yw0-f174.google.com ([209.85.211.174]:33084 "EHLO mail-yw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752429AbZINLKR (ORCPT ); Mon, 14 Sep 2009 07:10:17 -0400 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=rkINxOTTp5axQCggYjYxAME+0fJJVHaEfuSS8aYw1Ic8mtoAZ8Ncv57lrmo+xI6bjJ tLMlXUaWx5WIxukzWAN94V22hXaYg5DaJ5FsedT+DCMm7dV4VMjTt5NkBDP+fASLmtmk 89NkUwr1BKyV6djk5NGWki8niJ+ILOUxy2ZY8= Date: Mon, 14 Sep 2009 20:10:02 +0900 From: Minchan Kim To: Jens Axboe Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, chris.mason@oracle.com, hch@infradead.org, tytso@mit.edu, akpm@linux-foundation.org, jack@suse.cz, trond.myklebust@fys.uio.no Subject: Re: [PATCH 4/7] writeback: use RCU to protect bdi_list Message-Id: <20090914201002.0ca94166.minchan.kim@barrios-desktop> In-Reply-To: <1252920994-11141-5-git-send-email-jens.axboe@oracle.com> References: <1252920994-11141-1-git-send-email-jens.axboe@oracle.com> <1252920994-11141-5-git-send-email-jens.axboe@oracle.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: 1257 Lines: 38 On Mon, 14 Sep 2009 11:36:31 +0200 Jens Axboe wrote: > Now that bdi_writeback_all() no longer handles integrity writeback, > it doesn't have to block anymore. This means that we can switch > bdi_list reader side protection to RCU. > > Signed-off-by: Jens Axboe > --- > fs/fs-writeback.c | 4 +- > include/linux/backing-dev.h | 1 + > mm/backing-dev.c | 76 +++++++++++++++++++++++++++++++------------ > mm/page-writeback.c | 8 ++-- > 4 files changed, 62 insertions(+), 27 deletions(-) > > diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c > index 5d4bd1c..d7592c7 100644 > --- a/fs/fs-writeback.c > +++ b/fs/fs-writeback.c > @@ -849,7 +849,7 @@ static void bdi_writeback_all(struct writeback_control *wbc) > > WARN_ON(wbc->sync_mode == WB_SYNC_ALL); > > - spin_lock(&bdi_lock); > + rcu_read_lock(); > > list_for_each_entry(bdi, &bdi_list, bdi_list) { list_for_each_entry_rcu? -- 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/