From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guoqing Jiang Subject: Re: [PATCH] mdraid: fix read/write bytes accounting Date: Tue, 23 Jun 2020 16:21:49 +0200 Message-ID: References: <20200605201953.11098-1-jeffm@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-raid-owner@vger.kernel.org To: Artur Paszkiewicz , jeffm@suse.com, linux-raid@vger.kernel.org, song@kernel.org Cc: nfbrown@suse.com, colyli@suse.com List-Id: linux-raid.ids Hi Artur, On 6/8/20 9:13 AM, Artur Paszkiewicz wrote: > On 6/5/20 10:19 PM, jeffm@suse.com wrote: >> The i/o accounting published in /proc/diskstats for mdraid is currently >> broken. md_make_request does the accounting for every bio passed but >> when a bio needs to be split, all the split bios are also submitted >> through md_make_request, resulting in multiple accounting. > Hi Jeff, > > I sent a patch a few days ago which should fix this issue. Can you check > it out? > > https://marc.info/?l=linux-raid&m=159102814820539 I need to account some extra statistics for bio such as latency and size, so it is kind of relies on your patch, then I read the code again. And besides my previous comment. I think you don't need clone bio for all personalities. For md-multipath, raid1 and raid10, you can track the start time by add it to those structures (multipath_bh, r1bio and r10bio), then one extra copy could be avoided. What do you think? Thanks, Guoqing