From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by mail19.linbit.com (LINBIT Mail Daemon) with ESMTP id A936F42178C for ; Thu, 8 Dec 2022 01:36:04 +0100 (CET) Date: Thu, 8 Dec 2022 00:35:55 +0000 From: Keith Busch To: Chaitanya Kulkarni Message-ID: References: <20221207223204.22459-1-gulam.mohamed@oracle.com> <09be5cbe-9251-d28c-e91a-3f2e5e9e99f2@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <09be5cbe-9251-d28c-e91a-3f2e5e9e99f2@nvidia.com> Cc: "nvdimm@lists.linux.dev" , "linux-kernel@vger.kernel.org" , "song@kernel.org" , "dm-devel@redhat.com" , "ira.weiny@intel.com" , "agk@redhat.com" , "drbd-dev@lists.linbit.com" , "dave.jiang@intel.com" , "vishal.l.verma@intel.com" , "konrad.wilk@oracle.com" , "joe.jin@oracle.com" , "kent.overstreet@gmail.com" , "ngupta@vflare.org" , "senozhatsky@chromium.org" , Gulam Mohamed , "snitzer@kernel.org" , "colyli@suse.de" , "linux-block@vger.kernel.org" , "linux-bcache@vger.kernel.org" , "dan.j.williams@intel.com" , Jens Axboe , "linux-raid@vger.kernel.org" , "martin.petersen@oracle.com" , "philipp.reisner@linbit.com" , "junxiao.bi@oracle.com" , "minchan@kernel.org" , "lars.ellenberg@linbit.com" Subject: Re: [Drbd-dev] [RFC for-6.2/block V2] block: Change the granularity of io ticks from ms to ns List-Id: "*Coordination* of development, patches, contributions -- *Questions* \(even to developers\) go to drbd-user, please." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Dec 07, 2022 at 11:17:12PM +0000, Chaitanya Kulkarni wrote: > On 12/7/22 15:08, Jens Axboe wrote: > > > > My default peak testing runs at 122M IOPS. That's also the peak IOPS of > > the devices combined, and with iostats disabled. If I enabled iostats, > > then the performance drops to 112M IOPS. It's no longer device limited, > > that's a drop of about 8.2%. > > > > Wow, clearly not acceptable that's exactly I asked for perf > numbers :). For the record, we did say per-io ktime_get() has a measurable performance harm and should be aggregated. https://www.spinics.net/lists/linux-block/msg89937.html