Messages in this thread | | | Date | Fri, 13 Oct 2023 10:01:48 +0800 | From | Ming Lei <> | Subject | Re: [PATCH] blk-mq: add module parameter to not run block kworker on isolated CPUs |
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Hi Tejun,
On Thu, Oct 12, 2023 at 09:55:55AM -1000, Tejun Heo wrote: > Hello, > > On Wed, Oct 11, 2023 at 08:39:05AM +0800, Ming Lei wrote: > > I appreciate that any specific suggestions about dealing with isolated CPUs > > generically for bound WQ can be shared. > > Oh, all I meant was whether we can at least collect this into or at least > adjacent to the existing housekeeping / isolcpu parameters. Let's say > there's someone who really wants to isolated some CPUs, how would they find > out the different parameters if they're scattered across different > subsystems?
AFAIK, the issue is reported on RH Openshift environment and it is real use case, some of CPUs are isolated for some dedicated tasks(such as network polling, ...) by passing "isolcpus=managed_irq nohz_full".
But blk-mq still queue kworker on these isolated CPUs, and cause very long latency in nvme IO workloads. Joe should know the story much more then me.
Thanks, Ming
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