}
}
+/*
+ * It'd be great if the workqueue API had a way to pass
+ * in a mask and had some smarts for more clever placement.
+ * For now we just round-robin here, switching for every
+ * BLK_MQ_CPU_WORK_BATCH queued items.
+ */
+static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx)
+{
+ int cpu = hctx->next_cpu;
+
+ if (--hctx->next_cpu_batch <= 0) {
+ int next_cpu;
+
+ next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask);
+ if (next_cpu >= nr_cpu_ids)
+ next_cpu = cpumask_first(hctx->cpumask);
+
+ hctx->next_cpu = next_cpu;
+ hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
+ }
+
+ return cpu;
+}
+
void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
{
if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state)))
else {
unsigned int 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
- * than the first CPU. Or we could round-robin here. For now,
- * just queue on the first CPU.
- */
- cpu = cpumask_first(hctx->cpumask);
+ cpu = blk_mq_hctx_next_cpu(hctx);
kblockd_schedule_delayed_work_on(cpu, &hctx->run_work, 0);
}
}
else {
unsigned int 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
- * than the first CPU. Or we could round-robin here. For now,
- * just queue on the first CPU.
- */
- cpu = cpumask_first(hctx->cpumask);
+ cpu = blk_mq_hctx_next_cpu(hctx);
kblockd_schedule_delayed_work_on(cpu, &hctx->delay_work, tmo);
}
}
ctx->index_hw = hctx->nr_ctx;
hctx->ctxs[hctx->nr_ctx++] = ctx;
}
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ hctx->next_cpu = cpumask_first(hctx->cpumask);
+ hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
+ }
}
struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)