Messages in this thread | | | Subject | Re: [PATCH v3] blk-throtl: optimize IOPS throttle for large IO scenarios | From | Jens Axboe <> | Date | Sat, 14 Aug 2021 19:14:37 -0600 |
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On 8/1/21 9:51 PM, brookxu wrote: > From: Chunguang Xu <brookxu@tencent.com> > > After patch 54efd50 (block: make generic_make_request handle > arbitrarily sized bios), the IO through io-throttle may be larger, > and these IOs may be further split into more small IOs. However, > IOPS throttle does not seem to be aware of this change, which > makes the calculation of IOPS of large IOs incomplete, resulting > in disk-side IOPS that does not meet expectations. Maybe we should > fix this problem. > > We can reproduce it by set max_sectors_kb of disk to 128, set > blkio.write_iops_throttle to 100, run a dd instance inside blkio > and use iostat to watch IOPS: > > dd if=/dev/zero of=/dev/sdb bs=1M count=1000 oflag=direct > > As a result, without this change the average IOPS is 1995, with > this change the IOPS is 98.
Applied for 5.15, thanks.
> v3: Optimize the use of atomic variables. > v2: Use atomic variables to solve synchronization problems.
Just a note for the future, changelog stuff goes below the --- line.
-- Jens Axboe
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