On Tue, Aug 01, 2017 at 09:18:23AM -0600, Jens Axboe wrote: > On 07/14/2017 02:41 AM, Ming Lei wrote: > > From: Ming Lei <minlei@xxxxxxxxxx> > > > > When blk_mq_get_request() failed, preempt counter isn't > > released, and blk_mq_make_request() doesn't release the counter > > too. > > > > This patch fixes the issue, and makes sure that preempt counter > > is only held if rq is allocated successfully. The same policy is > > applied on .q_usage_counter too. > > Can you replace the 'get_cpu' bool with just a ctx, and change > the logic to put it if set? I think that would be cleaner to read, > generally I hate bool 'do_something' variables that are set. It's > much cleaner to have: > > if (likely(!data->ctx)) > data->ctx = local_ctx = blk_mq_get_ctx(q); > > and have the put case be > > if (local_ctx) > blk_mq_put_ctx(local_ctx); > > Either that, or at least just have blk_mq_get_request() do: > > drop_ctx = data->ctx == NULL; > > instead. The 'get_cpu' naming is confusing, we're worried about dropping > the sw queue here, the fact that it's related to get/put_cpu() need not > bubble up here. Good point, V2 is sent out with this change. Thanks your suggestion! -- Ming
