From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Subject: Re: [PATCH 3/3] ext4: optimize quota write locking Date: Thu, 1 Apr 2010 11:14:14 +0200 Message-ID: <20100401091414.GF3322@quack.suse.cz> References: <1269692140-5375-1-git-send-email-dmonakhov@openvz.org> <1269692140-5375-2-git-send-email-dmonakhov@openvz.org> <1269692140-5375-3-git-send-email-dmonakhov@openvz.org> <1269692140-5375-4-git-send-email-dmonakhov@openvz.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, jack@suse.cz To: Dmitry Monakhov Return-path: Content-Disposition: inline In-Reply-To: <1269692140-5375-4-git-send-email-dmonakhov@openvz.org> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Sat 27-03-10 15:15:40, Dmitry Monakhov wrote: > Quota inode is append only. In most cases writes performed > to allocated blocks before i_size. Currently we grup i_mutex > for each quota write to protect i_size and i_mtime. But in most > cases i_size not changed. And i_mtime is not that important > as for regular files. So let's update it only when quota file > increased. This allow us to avoid i_mutex in most cases. But this won't help performance at all because dqio_mutex serializes writes to the file already, right? Honza -- Jan Kara SUSE Labs, CR