From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753046AbcIQTtj (ORCPT ); Sat, 17 Sep 2016 15:49:39 -0400 Received: from mail-pa0-f48.google.com ([209.85.220.48]:36433 "EHLO mail-pa0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751532AbcIQTtb (ORCPT ); Sat, 17 Sep 2016 15:49:31 -0400 Date: Sat, 17 Sep 2016 12:49:27 -0700 From: Omar Sandoval To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, Alexei Starovoitov Subject: Re: [PATCH] sbitmap: don't update the allocation hint on clear after resize Message-ID: <20160917194927.GA28432@vader> References: <54286aca-7ce6-5138-9189-83a2dff444b1@fb.com> <29fb3ca2c78084b3548fd87c0c9a946e2b68bffc.1474139647.git.osandov@fb.com> <227b6d24-8500-4ec9-5999-fd83f7221b8a@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <227b6d24-8500-4ec9-5999-fd83f7221b8a@fb.com> User-Agent: Mutt/1.7.0 (2016-08-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Sep 17, 2016 at 01:39:59PM -0600, Jens Axboe wrote: > On 09/17/2016 01:20 PM, Omar Sandoval wrote: > > From: Omar Sandoval > > > > If we have a bunch of high-numbered bits allocated and then we resize > > the struct sbitmap_queue, when those bits get cleared, we'll update the > > hint and then have to re-randomize it repeatedly. Avoid that by checking > > that the cleared bit is still a valid hint. No measurable performance > > difference in the common case. > > > > Signed-off-by: Omar Sandoval > > --- > > Jens, > > > > Small tweak to patch 6 that occurred to me after I sent the series out. > > Feel free to fold it in to patch 6 or apply it separately as you see > > fit. > > No worries. I can't fold since the series was already applied, so I just > added the extra patch. > Okay with me, thanks! -- Omar