From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Chinner Subject: Re: [RFC v2 07/10] vfs: fork one kthread to update data temperature Date: Thu, 27 Sep 2012 17:01:17 +1000 Message-ID: <20120927070117.GR15236@dastard> References: <1348404995-14372-1-git-send-email-zwu.kernel@gmail.com> <1348404995-14372-8-git-send-email-zwu.kernel@gmail.com> <20120927040357.GO15236@dastard> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, linuxram@linux.vnet.ibm.com, viro@zeniv.linux.org.uk, cmm@us.ibm.com, tytso@mit.edu, marco.stornelli@gmail.com, stroetmann@ontolinux.com, diegocg@gmail.com, chris@csamuel.org, Zhi Yong Wu To: Zhi Yong Wu Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Thu, Sep 27, 2012 at 02:54:22PM +0800, Zhi Yong Wu wrote: > On Thu, Sep 27, 2012 at 12:03 PM, Dave Chinner wrote: > > On Sun, Sep 23, 2012 at 08:56:32PM +0800, zwu.kernel@gmail.com wrote: > >> From: Zhi Yong Wu > >> > >> Fork and run one kernel kthread to calculate > >> that temperature based on some metrics kept > >> in custom frequency data structs, and store > >> the info in the hash table. > > > > No new kthreads, please. Use a per-superblock workqueue and a struct > > delayed_work to run periodic work on each superblock. > If no new kthread is created, which kthread will work on these > delayed_work tasks? One of the kworker threads that service the workqueue infrastructure. Cheers, Dave. -- Dave Chinner david@fromorbit.com