Messages in this thread | ![/](/images/icornerl.gif) | | Date | Mon, 24 Jul 2023 17:48:22 +0200 | From | Greg KH <> | Subject | Re: [PATCH] io_uring: Use io_schedule* in cqring wait |
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On Mon, Jul 24, 2023 at 04:35:43PM +0100, Phil Elwell wrote: > Hi Andres, > > With this commit applied to the 6.1 and later kernels (others not > tested) the iowait time ("wa" field in top) in an ARM64 build running > on a 4 core CPU (a Raspberry Pi 4 B) increases to 25%, as if one core > is permanently blocked on I/O. The change can be observed after > installing mariadb-server (no configuration or use is required). After > reverting just this commit, "wa" drops to zero again.
This has been discussed already: https://lore.kernel.org/r/12251678.O9o76ZdvQC@natalenko.name
It's not a bug, mariadb does have pending I/O, so the report is correct, but the CPU isn't blocked at all.
thanks,
greg k-h
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