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NVMe: Simplify queue lookup

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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>
This commit is contained in:
Matthew Wilcox 2011-03-16 16:52:19 -04:00
parent 3cb967c039
commit 9ecdc94621
1 changed files with 6 additions and 6 deletions
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12
drivers/block/nvme.c
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@ -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) static struct nvme_queue *get_nvmeq(struct nvme_ns *ns)
{ {
int qid, cpu = get_cpu(); return ns->dev->queues[get_cpu() + 1];
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];
} }
static void put_nvmeq(struct nvme_queue *nvmeq) 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++; 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; return 0;
} }