From: Tejun Heo <tj@kernel.org> To: Yu Kuai <yukuai1@huaweicloud.com> Cc: mkoutny@suse.com, axboe@kernel.dk, ming.lei@redhat.com, cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, "yukuai (C)" <yukuai3@huawei.com> Subject: Re: [PATCH v7 4/9] blk-throttle: fix io hung due to configuration updates Date: Wed, 17 Aug 2022 07:52:45 -1000 [thread overview] Message-ID: <Yv0q7T5Eg6MzOIuU@slm.duckdns.org> (raw) In-Reply-To: <215b4842-c09f-d622-7127-c8b1d9ce3aa9@huaweicloud.com> On Wed, Aug 17, 2022 at 09:30:30AM +0800, Yu Kuai wrote: > > Would it be easier if the fields were signed? It's fragile and odd to > > explain "these are unsigned but if they underflow they behave just like > > signed when added" when they can just be signed. Also, I have a hard time > > understand what "preempt" means above. > > I think preempt shound never happen based on current FIFO > implementation, perhaps Can you elaborate what "preempt" is? > > > + if (bps_limit != U64_MAX) > > > + tg->bytes_skipped[rw] += > > > + calculate_bytes_allowed(bps_limit, jiffy_elapsed) - > > > + tg->bytes_disp[rw]; > > > + if (iops_limit != UINT_MAX) > > > + tg->io_skipped[rw] += > > > + calculate_io_allowed(iops_limit, jiffy_elapsed) - > > > + tg->io_disp[rw]; > > > > So, this is calculating the budgets to carry over. Can we name them > > accordingly? I don't know what "skipped" means. > > Yeah, thanks for you advice, art of naming is a little hard for me... > How do you think about these name: extended_bytes/io_budget? How about carryover_{ios|bytes}? Thanks. -- tejun
WARNING: multiple messages have this Message-ID (diff)
From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> To: Yu Kuai <yukuai1-XF6JlduFytWkHkcT6e4Xnw@public.gmane.org> Cc: mkoutny-IBi9RG/b67k@public.gmane.org, axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org, 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, "yukuai (C)" <yukuai3-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> Subject: Re: [PATCH v7 4/9] blk-throttle: fix io hung due to configuration updates Date: Wed, 17 Aug 2022 07:52:45 -1000 [thread overview] Message-ID: <Yv0q7T5Eg6MzOIuU@slm.duckdns.org> (raw) In-Reply-To: <215b4842-c09f-d622-7127-c8b1d9ce3aa9-XF6JlduFytWkHkcT6e4Xnw@public.gmane.org> On Wed, Aug 17, 2022 at 09:30:30AM +0800, Yu Kuai wrote: > > Would it be easier if the fields were signed? It's fragile and odd to > > explain "these are unsigned but if they underflow they behave just like > > signed when added" when they can just be signed. Also, I have a hard time > > understand what "preempt" means above. > > I think preempt shound never happen based on current FIFO > implementation, perhaps Can you elaborate what "preempt" is? > > > + if (bps_limit != U64_MAX) > > > + tg->bytes_skipped[rw] += > > > + calculate_bytes_allowed(bps_limit, jiffy_elapsed) - > > > + tg->bytes_disp[rw]; > > > + if (iops_limit != UINT_MAX) > > > + tg->io_skipped[rw] += > > > + calculate_io_allowed(iops_limit, jiffy_elapsed) - > > > + tg->io_disp[rw]; > > > > So, this is calculating the budgets to carry over. Can we name them > > accordingly? I don't know what "skipped" means. > > Yeah, thanks for you advice, art of naming is a little hard for me... > How do you think about these name: extended_bytes/io_budget? How about carryover_{ios|bytes}? Thanks. -- tejun
next prev parent reply other threads:[~2022-08-17 17:52 UTC|newest] Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-08-02 14:04 [PATCH v7 0/9] bugfix and cleanup for blk-throttle Yu Kuai 2022-08-02 14:04 ` Yu Kuai 2022-08-02 14:04 ` [PATCH v7 1/9] blk-throttle: fix that io throttle can only work for single bio Yu Kuai 2022-08-16 19:37 ` Tejun Heo 2022-08-17 1:13 ` Yu Kuai 2022-08-17 1:13 ` Yu Kuai 2022-08-17 17:50 ` Tejun Heo 2022-08-18 1:23 ` Yu Kuai 2022-08-18 1:23 ` Yu Kuai 2022-08-22 3:06 ` Yu Kuai 2022-08-22 3:06 ` Yu Kuai 2022-08-22 7:25 ` Tejun Heo 2022-08-22 7:25 ` Tejun Heo 2022-08-22 7:44 ` Yu Kuai 2022-08-22 7:44 ` Yu Kuai 2022-08-02 14:04 ` [PATCH v7 2/9] blk-throttle: prevent overflow while calculating wait time Yu Kuai 2022-08-02 14:04 ` [PATCH v7 3/9] blk-throttle: factor out code to calculate ios/bytes_allowed Yu Kuai 2022-08-02 14:04 ` Yu Kuai 2022-08-16 19:47 ` Tejun Heo 2022-08-17 1:32 ` Yu Kuai 2022-08-17 1:32 ` Yu Kuai 2022-08-02 14:04 ` [PATCH v7 4/9] blk-throttle: fix io hung due to configuration updates Yu Kuai 2022-08-02 14:04 ` Yu Kuai 2022-08-16 20:01 ` Tejun Heo 2022-08-16 20:01 ` Tejun Heo 2022-08-17 1:30 ` Yu Kuai 2022-08-17 1:30 ` Yu Kuai 2022-08-17 17:52 ` Tejun Heo [this message] 2022-08-17 17:52 ` Tejun Heo 2022-08-18 1:16 ` Yu Kuai 2022-08-18 1:16 ` Yu Kuai 2022-08-19 17:33 ` Tejun Heo 2022-08-19 17:33 ` Tejun Heo 2022-08-02 14:04 ` [PATCH v7 5/9] blk-throttle: improve handling of re-entered bio for bps limit Yu Kuai 2022-08-02 14:04 ` Yu Kuai 2022-08-16 20:02 ` Tejun Heo 2022-08-16 20:02 ` Tejun Heo 2022-08-02 14:04 ` [PATCH v7 6/9] blk-throttle: use 'READ/WRITE' instead of '0/1' Yu Kuai 2022-08-02 14:04 ` Yu Kuai 2022-08-16 20:03 ` Tejun Heo 2022-08-17 1:33 ` Yu Kuai 2022-08-17 1:33 ` Yu Kuai 2022-08-02 14:04 ` [PATCH v7 7/9] blk-throttle: calling throtl_dequeue/enqueue_tg in pairs Yu Kuai 2022-08-02 14:04 ` Yu Kuai 2022-08-02 14:04 ` [PATCH v7 8/9] blk-throttle: cleanup tg_update_disptime() Yu Kuai 2022-08-02 14:04 ` Yu Kuai 2022-08-16 20:09 ` Tejun Heo 2022-08-17 1:38 ` Yu Kuai 2022-08-17 1:38 ` Yu Kuai 2022-08-02 14:04 ` [PATCH v7 9/9] blk-throttle: clean up flag 'THROTL_TG_PENDING' Yu Kuai 2022-08-02 14:04 ` Yu Kuai 2022-08-16 20:14 ` Tejun Heo 2022-08-17 1:45 ` Yu Kuai 2022-08-17 1:45 ` Yu Kuai 2022-08-17 17:54 ` Tejun Heo 2022-08-17 17:54 ` Tejun Heo 2022-08-18 9:29 ` Yu Kuai 2022-08-18 9:29 ` Yu Kuai 2022-08-19 17:35 ` Tejun Heo 2022-08-19 17:35 ` Tejun Heo 2022-08-13 5:59 ` [PATCH v7 0/9] bugfix and cleanup for blk-throttle Yu Kuai 2022-08-13 5:59 ` Yu Kuai
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