From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH v2 01/14] block: Generalized bio pool freeing Date: Thu, 24 May 2012 09:19:14 -0700 Message-ID: <20120524161914.GD27983@google.com> References: <1337817771-25038-1-git-send-email-koverstreet@google.com> <1337817771-25038-2-git-send-email-koverstreet@google.com> <20120524160944.GB27983@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org, yehuda-L5o5AL9CYN0tUFlbccrkMA@public.gmane.org, dm-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, neilb-l3A5Bk7waGM@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-bcache-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, mpatocka-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, bharrosh-C4P08NqkoRlBDgjK7y7TUQ@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, sage-BnTBU8nroG7k1uMJSBkQmQ@public.gmane.org, agk-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, drbd-dev-cunTk1MwBs8qoQakbn7OcQ@public.gmane.org To: Kent Overstreet Return-path: Content-Disposition: inline In-Reply-To: <20120524160944.GB27983-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: drbd-dev-bounces-cunTk1MwBs8qoQakbn7OcQ@public.gmane.org Errors-To: drbd-dev-bounces-cunTk1MwBs8qoQakbn7OcQ@public.gmane.org List-Id: linux-fsdevel.vger.kernel.org On Thu, May 24, 2012 at 09:09:44AM -0700, Tejun Heo wrote: > On Wed, May 23, 2012 at 05:02:38PM -0700, Kent Overstreet wrote: > > With the old code, when you allocate a bio from a bio pool you have to > > implement your own destructor that knows how to find the bio pool the > > bio was originally allocated from. > > > > This adds a new field to struct bio (bi_pool) and changes > > bio_alloc_bioset() to use it. This makes various bio destructors > > unnecessary, so they're then deleted. > > > > Signed-off-by: Kent Overstreet > > Change-Id: I5eb66c1d6910757f4af8755b8857dcbe4619cf8d > > Please drop Change-ID tag and it would be great how you tested the > changes, other than that, > > Acked-by: Tejun Heo To add a bit here too. Please explain "why" you're making this change. Is it because bi_destructor interface is cumbersome? Adding bi_pool is overhead - why is it justified? Is it because one pointer is fine to add to struct bio (which I kinda agree) or are there future changes which will reverse the overhead (which is the case here). In general, I find the descriptions insufficient. They don't describe the reasons and reasoning behind the patch. Thanks. -- tejun