From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [PATCH -next v5 4/8] blk-throttle: fix io hung due to config updates Date: Sat, 25 Jun 2022 10:41:23 -0600 Message-ID: <7e14a11b-225e-13c4-35ff-762eafd20b70@kernel.dk> References: <20220528064330.3471000-1-yukuai3@huawei.com> <20220528064330.3471000-5-yukuai3@huawei.com> <20220622172621.GA28246@blackbody.suse.cz> <20220623162620.GB16004@blackbody.suse.cz> <75b3cdcc-1aa3-7259-4900-f09a2a081716@huawei.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=CiiTdw5nwmdQxjSzvtjOG6uYyrass8pWwqawj8avJ5Y=; b=ZdlS1l2K0yddb8XT+8VtvNpjN/CVImDLEORZgY0s7okUSI8qLcWyCyaDjOJJDeX6MR x9/ddt1ZSDs5dOI5/CTqFNN9tdyhRRqsHxq/Adk41okptoPxOTvPCBdEDz4viCdXmOFs O7yPMl00IseDazDTQszNOg232uVglii7zgJPHi9Sp+zWDwvBbCARyNINUZiap/yzOu3o Nv9yBqvGpew70x+p1YWq5qBXreAi1u2qWT642bK3rucMDI5nVjuHZZPSu2F5suQ1i/8N z8n0zlESYixxHA2a/W4PHTkLBiHoyIOk9SL5dBOzGj6InF7BAulw4JAvmCr3kxJELEus iATg== Content-Language: en-US In-Reply-To: <75b3cdcc-1aa3-7259-4900-f09a2a081716-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" To: Yu Kuai , =?UTF-8?Q?Michal_Koutn=c3=bd?= , tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org Cc: ming.lei-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, yi.zhang-hv44wF8Li93QT0dZR+AlfA@public.gmane.org On 6/25/22 2:36 AM, Yu Kuai wrote: > ? 2022/06/24 0:26, Michal Koutn? ??: >> On Thu, Jun 23, 2022 at 08:27:11PM +0800, Yu Kuai wrote: >>>> Here we may allow to dispatch a bio above current slice's >>>> calculate_bytes_allowed() if bytes_skipped is already >0. >>> >>> Hi, I don't expect that to happen. For example, if a bio is still >>> throttled, then old slice is keeped with proper 'bytes_skipped', >>> then new wait time is caculated based on (bio_size - bytes_skipped). >>> >>> After the bio is dispatched(I assum that other bios can't preempt), >> >> With this assumptions it adds up as you write. I believe we're in >> agreement. >> >> It's the same assumption I made below (FIFO everywhere, i.e. no >> reordering). So the discussed difference shouldn't really be negative >> (and if the assumption didn't hold, so the modular arithmetic yields >> corerct bytes_skipped value). > Yes, nice that we're in aggreement. > > I'll wait to see if Tejun has any suggestions. I flushed more emails from spam again. Please stop using the buggy huawei address until this gets resolved, your patches are getting lost left and right and I don't have time to go hunting for emails. -- Jens Axboe