From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:35014 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726905AbeINSOQ (ORCPT ); Fri, 14 Sep 2018 14:14:16 -0400 Date: Fri, 14 Sep 2018 14:59:52 +0200 From: David Sterba To: Liu Bo Cc: linux-btrfs@vger.kernel.org Subject: Re: [PATCH v2] Btrfs: skip set_page_dirty if eb is dirty Message-ID: <20180914125952.GC5847@twin.jikos.cz> Reply-To: dsterba@suse.cz References: <1536703587-94565-1-git-send-email-bo.liu@linux.alibaba.com> <1536860682-41012-1-git-send-email-bo.liu@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1536860682-41012-1-git-send-email-bo.liu@linux.alibaba.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Fri, Sep 14, 2018 at 01:44:42AM +0800, Liu Bo wrote: > As long as @eb is marked with EXTENT_BUFFER_DIRTY, all of its pages > are dirty, so no need to set pages dirty again. > > Ftrace showed that the loop took 10us on my dev box, so removing this > can save us at least 10us if eb is already dirty. > > Signed-off-by: Liu Bo Reviewed-by: David Sterba