From: Tejun Heo Subject: Re: [PATCH v3 1/2] block: skip elevator data initialization for flush requests Date: Fri, 4 Feb 2011 16:08:46 +0100 Message-ID: <20110204150826.GJ12133@htj.dyndns.org> References: <20110201185225.GT14211@htj.dyndns.org> <1296600373-6906-1-git-send-email-snitzer@redhat.com> <20110202225549.GA28109@redhat.com> <4D4AAC9A.4050407@fusionio.com> <20110203133820.GF2570@htj.dyndns.org> <20110204150456.GD32190@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jens Axboe , Mike Snitzer , "tytso@mit.edu" , "djwong@us.ibm.com" , "shli@kernel.org" , "neilb@suse.de" , "adilger.kernel@dilger.ca" , "jack@suse.cz" , "linux-kernel@vger.kernel.org" , "kmannth@us.ibm.com" , "cmm@us.ibm.com" , "linux-ext4@vger.kernel.org" , "rwheeler@redhat.com" , "hch@lst.de" , "josef@redhat.com" , "jmoyer@redhat.com" To: Vivek Goyal Return-path: Content-Disposition: inline In-Reply-To: <20110204150456.GD32190@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Hello, On Fri, Feb 04, 2011 at 10:04:57AM -0500, Vivek Goyal wrote: > > The rationale behind suggesting was that it indicates to the allocator > > that the request may be sorted as how the request will be used is > > communicated using @rw_flags to the allocator. The patch is buggy > > that the flag actually ends up on the request. Any better idea how to > > communicate it? > > Though you did not like the V1 of patch, personally I also liked just parsing > FLUSH or FUA flag in get_request(). > > Or how about intoducing a helper function blk_rq_should_init_elevator() > or something like that and this function will parse FLUSH, FUA flags. I suppose it's Jens' call, but if the FLUSH/FUA testing goes inside the alloc function, please decorate with big fat comment and mention it in the comment for the union definition too. Thank you. -- tejun