__blk_mq_run_hw

static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
{
    int srcu_idx;
 
    /*
     * We should be running this queue from one of the CPUs that
     * are mapped to it.
     *
     * There are at least two related races now between setting
     * hctx->next_cpu from blk_mq_hctx_next_cpu() and running
     * __blk_mq_run_hw_queue():
     *
     * - hctx->next_cpu is found offline in blk_mq_hctx_next_cpu(),
     *   but later it becomes online, then this warning is harmless
     *   at all
     *
     * - hctx->next_cpu is found online in blk_mq_hctx_next_cpu(),
     *   but later it becomes offline, then the warning can't be
     *   triggered, and we depend on blk-mq timeout handler to
     *   handle dispatched requests to this hctx
     */
    if (!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) &&
        cpu_online(hctx->next_cpu)) {
        printk(KERN_WARNING "run queue from wrong CPU %d, hctx %s\n",
            raw_smp_processor_id(),
            cpumask_empty(hctx->cpumask) ? "inactive": "active");
        dump_stack();
    }
 
    /*
     * We can't run the queue inline with ints disabled. Ensure that
     * we catch bad users of this early.
     */
    WARN_ON_ONCE(in_interrupt());
 
    might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING);
 
    hctx_lock(hctx, &srcu_idx);
    blk_mq_sched_dispatch_requests(hctx);
    hctx_unlock(hctx, srcu_idx);
}
函数源码
