Re: [PATCH 0/5] btrfs/282: resolve intermittent failures

Qu Wenruo
2023-12-07T09:49:06Z

On 2023/12/7 17:50, David Disseldorp wrote:
> btrfs/282 fails intermittently under some circumstances. This patchset
> adds dmdelay to make storage latencies more uniform and slightly
> increases throttled rate tolerances.

My concern using dm_delay is, is the delay per-merged-bio or something else?

If the delay is only per-bio (after merge), then I'm afraid it would not
be good enough.

The bio plug we use in scrub can have much higher chance to result a
difference in the scrub speed.

We may want a delay behavior which can take bio size into consideration
at least.

Thanks,
Qu

>
> common/dmdelay | 13 ++++---------
> tests/btrfs/282 | 43 +++++++++++++++++++++++++++++--------------
> tests/btrfs/282.out | 2 +-
> tests/xfs/311 | 2 +-
> 4 files changed, 35 insertions(+), 25 deletions(-)
>
>