From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:49141 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752146AbdJTInH (ORCPT ); Fri, 20 Oct 2017 04:43:07 -0400 From: Johannes Thumshirn To: Elena Reshetova Cc: axboe@kernel.dk, james.bottomley@hansenpartnership.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, linux-btrfs@vger.kernel.org, peterz@infradead.org, gregkh@linuxfoundation.org, fujita.tomonori@lab.ntt.co.jp, mingo@redhat.com, clm@fb.com, jbacik@fb.com, dsterba@suse.com, keescook@chromium.org Subject: Re: [PATCH 0/6] v4 block refcount conversion patches In-Reply-To: <1508487362-26663-1-git-send-email-elena.reshetova@intel.com> (Elena Reshetova's message of "Fri, 20 Oct 2017 11:15:56 +0300") References: <1508487362-26663-1-git-send-email-elena.reshetova@intel.com> Date: Fri, 20 Oct 2017 10:43:03 +0200 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Elena Reshetova writes: > Elena Reshetova (6): > block: convert bio.__bi_cnt from atomic_t to refcount_t > block: convert blk_queue_tag.refcnt from atomic_t to refcount_t > block: convert blkcg_gq.refcnt from atomic_t to refcount_t > block: convert io_context.active_ref from atomic_t to refcount_t > block: convert bsg_device.ref_count from atomic_t to refcount_t > drivers, block: convert xen_blkif.refcnt from atomic_t to refcount_t Hi Elena, While the bsg ref_count is cheap, do you have any numbers how the other conversions compare in performance (throughput and latency) vs atomics? It should be quite easy to measure against a null_blk device. Thanks a lot, Johannes -- Johannes Thumshirn Storage jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850