NVMe: Simplify queue lookup (9ecdc946) · Commits · 戴 / test

Fill in all the num_possible_cpus() entries with duplicate pointers. This reduces the complexity of the frequently-called get_nvmeq(), as well as avoiding a bug in it when there are fewer queues than CPUs. Reported-by:

Shane Michael Matthews <shane.matthews@intel.com> Signed-off-by:

Matthew Wilcox <matthew.r.wilcox@intel.com>

drivers/block/nvme.c

+6 −6

Original line number	Diff line number	Diff line
		@@ -221,12 +221,7 @@ static void cancel_cmdid_data(struct nvme_queue *nvmeq, int cmdid)

		static struct nvme_queue get_nvmeq(struct nvme_ns ns)
		{
		int qid, cpu = get_cpu();
		if (cpu < ns->dev->queue_count)
		qid = cpu + 1;
		else
		qid = (cpu % rounddown_pow_of_two(ns->dev->queue_count)) + 1;
		return ns->dev->queues[qid];
		return ns->dev->queues[get_cpu() + 1];
		}

		static void put_nvmeq(struct nvme_queue *nvmeq)
		@@ -1316,6 +1311,11 @@ static int __devinit nvme_setup_io_queues(struct nvme_dev *dev)
		dev->queue_count++;
		}

		for (; i < num_possible_cpus(); i++) {
		int target = i % rounddown_pow_of_two(dev->queue_count - 1);
		dev->queues[i + 1] = dev->queues[target + 1];
		}

		return 0;
		}

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