Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161832AbdDUQkO (ORCPT ); Fri, 21 Apr 2017 12:40:14 -0400 Received: from mail-io0-f170.google.com ([209.85.223.170]:34713 "EHLO mail-io0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161808AbdDUQkC (ORCPT ); Fri, 21 Apr 2017 12:40:02 -0400 Subject: Re: [PATCH 0/5] v2: block subsystem refcounter conversions To: Peter Zijlstra References: <1492687644-4405-1-git-send-email-elena.reshetova@intel.com> <20170420135651.GA26595@infradead.org> <2236FBA76BA1254E88B949DDB74E612B41C8DA36@IRSMSX102.ger.corp.intel.com> <20170420183319.GB103004@gmail.com> <2236FBA76BA1254E88B949DDB74E612B41C8E21B@IRSMSX102.ger.corp.intel.com> <31311853-3554-cefe-1210-2ffae1a20058@kernel.dk> <20170421152241.q45w3ckjax5xiddq@hirez.programming.kicks-ass.net> Cc: "Reshetova, Elena" , Eric Biggers , Kees Cook , Christoph Hellwig , "james.bottomley@hansenpartnership.com" , "linux-kernel@vger.kernel.org" , "linux-block@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "linux-btrfs@vger.kernel.org" , "gregkh@linuxfoundation.org" , "fujita.tomonori@lab.ntt.co.jp" , "mingo@redhat.com" , "clm@fb.com" , "jbacik@fb.com" , "dsterba@suse.com" From: Jens Axboe Message-ID: <99e3518a-bb1a-cab2-80b8-dd466827b5e6@kernel.dk> Date: Fri, 21 Apr 2017 10:29:45 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20170421152241.q45w3ckjax5xiddq@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 670 Lines: 17 On 04/21/2017 09:22 AM, Peter Zijlstra wrote: > On Fri, Apr 21, 2017 at 08:03:13AM -0600, Jens Axboe wrote: >> You have it so easy - the code is completely standalone, building a >> small test framework around it and measuring performance in _user space_ >> is trivial. > > Something like this you mean: > > https://lkml.kernel.org/r/20170322165144.dtidvvbxey7w5pbd@hirez.programming.kicks-ass.net Yes, exactly. But it'd be great to see better coverage of the API, and various cases of X threads running operations on the same refcount, so we get a full view of that side too. The above looks like just counting cycles for a single op of foo_inc(). -- Jens Axboe