Messages in this thread | | | Date | Tue, 24 Oct 2023 07:45:10 +0800 | From | Ming Lei <> | Subject | Re: [PATCH V2] blk-mq: don't schedule block kworker on isolated CPUs |
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On Fri, Oct 13, 2023 at 08:47:58PM +0800, Ming Lei wrote: > Kernel parameter of `isolcpus=` or 'nohz_full=' are used for isolating CPUs > for specific task, and user often won't want block IO to disturb these CPUs, > also long IO latency may be caused if blk-mq kworker is scheduled on these > isolated CPUs. > > Kernel workqueue only respects this limit for WQ_UNBOUND, for bound wq, > the responsibility should be on wq user. > > So don't not run block kworker on isolated CPUs by ruling out isolated CPUs > from hctx->cpumask. Meantime in cpuhp handler, use queue map to check if > all CPUs in this hw queue are offline, this way can avoid any cost in fast > IO code path. > > Cc: Juri Lelli <juri.lelli@redhat.com> > Cc: Andrew Theurer <atheurer@redhat.com> > Cc: Joe Mario <jmario@redhat.com> > Cc: Sebastian Jug <sejug@redhat.com> > Cc: Frederic Weisbecker <frederic@kernel.org> > Signed-off-by: Ming Lei <ming.lei@redhat.com> > --- > V2: > - remove module parameter, meantime use queue map to check if > all cpus in one hctx are offline
Hello Guys,
Ping...
Thanks, Ming
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