On Mon, Jun 19, 2023 at 6:00 AM Yu Kuai [off-list ref] wrote:

Hi,

在 2023/06/19 18:26, Paul Menzel 写道:

quoted

Dear Yu,


Thank you for your patch. Some minor nits from my side, you can also
ignore.

Am 18.06.23 um 16:25 schrieb Yu Kuai:

quoted

From: Yu Kuai <redacted>

Commit 0c0be98bbe67 ("md/raid10: prevent unnecessary calls to wake_up()
in fast path") missed one place, for example, while testing with:

… one place. For example, with

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fio -direct=1 -rw=write/randwrite -iodepth=1 ...

Then plug and unplug will be called for each io, then wake_up() from

Maybe:

     fio -direct=1 -rw=write/randwrite -iodepth=1 ...

plug und unplug are called for each io, then …

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raid10_unplug() will cause lock contention as well.

Maybe paste the perf command and output?

Related test and test result and perf result can be found in the below
Link.

We don't need a lot of details of the test results in the commit log. But a
quick summary of the performance result can be really helpful here.
Something like: on array X, fio job Y, before the patch we got AAA, with
the patch, we got BBB.

Other than this, the patch looks good to me.

Thanks,
Song