diff options
author | Yu Kuai <yukuai3@huawei.com> | 2023-08-16 09:27:08 +0800 |
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committer | Jens Axboe <axboe@kernel.dk> | 2023-08-30 10:15:01 -0600 |
commit | eead0056648cef49d7b15c07ae612fa217083165 (patch) | |
tree | 5945d041f446ea086d237697ba969079d07d6082 /block/fops.c | |
parent | e8368b57c006dc0e02dcd8a9dc9f2060ff5476fe (diff) |
blk-throttle: consider 'carryover_ios/bytes' in throtl_trim_slice()
Currently, 'carryover_ios/bytes' is not handled in throtl_trim_slice(),
for consequence, 'carryover_ios/bytes' will be used to throttle bio
multiple times, for example:
1) set iops limit to 100, and slice start is 0, slice end is 100ms;
2) current time is 0, and 10 ios are dispatched, those io won't be
throttled and io_disp is 10;
3) still at current time 0, update iops limit to 1000, carryover_ios is
updated to (0 - 10) = -10;
4) in this slice(0 - 100ms), io_allowed = 100 + (-10) = 90, which means
only 90 ios can be dispatched without waiting;
5) assume that io is throttled in slice(0 - 100ms), and
throtl_trim_slice() update silce to (100ms - 200ms). In this case,
'carryover_ios/bytes' is not cleared and still only 90 ios can be
dispatched between 100ms - 200ms.
Fix this problem by updating 'carryover_ios/bytes' in
throtl_trim_slice().
Fixes: a880ae93e5b5 ("blk-throttle: fix io hung due to configuration updates")
Reported-by: zhuxiaohui <zhuxiaohui.400@bytedance.com>
Link: https://lore.kernel.org/all/20230812072116.42321-1-zhuxiaohui.400@bytedance.com/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230816012708.1193747-5-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/fops.c')
0 files changed, 0 insertions, 0 deletions