blk-mq: introduce blk_mq_hw_queue_first_cpu() to figure out first cpu
This patch introduces helper of blk_mq_hw_queue_first_cpu() for
figuring out the hctx's first cpu, and code duplication can be
avoided.
Cc: Stefan Haberland <sth@linux.vnet.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk-mq.c b/block/blk-mq.c
index db178c5..e05bd10 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1335,6 +1335,15 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
hctx_unlock(hctx, srcu_idx);
}
+static inline int blk_mq_first_mapped_cpu(struct blk_mq_hw_ctx *hctx)
+{
+ int cpu = cpumask_first_and(hctx->cpumask, cpu_online_mask);
+
+ if (cpu >= nr_cpu_ids)
+ cpu = cpumask_first(hctx->cpumask);
+ return cpu;
+}
+
/*
* It'd be great if the workqueue API had a way to pass
* in a mask and had some smarts for more clever placement.
@@ -1354,14 +1363,7 @@ static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx)
next_cpu = cpumask_next_and(next_cpu, hctx->cpumask,
cpu_online_mask);
if (next_cpu >= nr_cpu_ids)
- next_cpu = cpumask_first_and(hctx->cpumask, cpu_online_mask);
-
- /*
- * No online CPU is found, so have to make sure hctx->next_cpu
- * is set correctly for not breaking workqueue.
- */
- if (next_cpu >= nr_cpu_ids)
- next_cpu = cpumask_first(hctx->cpumask);
+ next_cpu = blk_mq_first_mapped_cpu(hctx);
hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
}
@@ -2430,10 +2432,7 @@ static void blk_mq_map_swqueue(struct request_queue *q)
/*
* Initialize batch roundrobin counts
*/
- hctx->next_cpu = cpumask_first_and(hctx->cpumask,
- cpu_online_mask);
- if (hctx->next_cpu >= nr_cpu_ids)
- hctx->next_cpu = cpumask_first(hctx->cpumask);
+ hctx->next_cpu = blk_mq_first_mapped_cpu(hctx);
hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
}
}
