From mboxrd@z Thu Jan 1 00:00:00 1970 From: kbusch@kernel.org (Keith Busch) Date: Thu, 4 Apr 2019 16:29:56 -0600 Subject: A kernel warning when entering suspend In-Reply-To: <20190404221948.GB30656@ming.t460p> References: <20190404085524.GA24927@ming.t460p> <20190404221948.GB30656@ming.t460p> Message-ID: <20190404222955.GA25081@localhost.localdomain> On Fri, Apr 05, 2019@06:19:50AM +0800, Ming Lei wrote: > Also in current blk-mq implementation, one irq may become shutdown > because of CPU hotplug even though when there is in-flight request > on the queue served by the irq. Then we depend on timeout handler to > cover this case, and this irq may be enabled in the timeout handler too, > please see nvme_poll_irqdisable(). Right, but when the last CPU mapped to an hctx is taken offline, we really ought to have blk-mq wait for that hctx to reap all outstanding requests before letting the notifier continue with offlining that CPU. We just don't have the infrastructure to freeze an individual hctx yet.