IO的中断返回也是相当让人激动的一件事情:
28470 1) | handle_irq() {
28471 1) 0.237 us | irq_to_desc();
28472 1) | handle_edge_irq() {
28473 1) 0.060 us | _raw_spin_lock();
28474 1) | ack_apic_edge() {
28475 1) 0.051 us | irq_complete_move();
28476 1) 0.044 us | irq_move_irq();
28477 1) 1.288 us | }
28478 1) | handle_irq_event() {
28479 1) 0.045 us | _raw_spin_unlock();
28480 1) | handle_irq_event_percpu() {
28481 1) | ahci_interrupt [libahci]() {
28482 1) 0.046 us | _raw_spin_lock();
28483 1) | ahci_handle_port_interrupt [libahci]() {
28484 1) | ata_qc_complete_multiple() { // qc = ata_qc_from_tag(ap, tag); (会得到最终的command)
28485 1) | ata_qc_complete() {
28486 1) | __ata_qc_complete() {
28487 1) 0.321 us | ata_sg_clean();
28488 1) | ata_scsi_qc_complete() {
28489 1) | scsi_done() {
28490 1) | blk_complete_request() {
28491 1) | __blk_complete_request() {
28492 1) 0.046 us | cpus_share_cache();
28493 1) 0.588 us | }
28494 1) 0.961 us | }
28495 1) 1.342 us | }
28496 1) 0.051 us | ata_qc_free();
28497 1) 2.146 us | }
28498 1) 3.
上面是我lenovo笔记本上ATA硬盘中断返回的代码, 其中断处理函数是ata_qc_complete,
发现, 环环相扣的结构体,从中断的scsi指令,我们能追溯到block层封装的request, 然后把这个request放到软中断中去了, 然后该赢中断平安返回,
下面就是软中断处理主场了!
28512 1) | irq_exit() {
28513 1) | __do_softirq() {
28514 1) 0.044 us | msecs_to_jiffies();
28515 1) | blk_done_softirq() {
28516 1) | scsi_softirq_done() {
28517 1) | scsi_decide_disposition() {
28518 1) 0.125 us | scsi_handle_queue_ramp_up();
28519 1) 0.563 us | }
28520 1) 0.070 us | scsi_log_completion();
28521 1) | scsi_finish_command() {
28522 1) | scsi_device_unbusy() {
28523 1) 0.044 us | _raw_spin_lock_irqsave();
28524 1) 0.042 us | _raw_spin_unlock();
28525 1) 0.049 us | _raw_spin_lock();
28526 1) 0.059 us | _raw_spin_unlock_irqrestore();
28527 1) 1.474 us | }
28528 1) 0.086 us | sd_done();
28529 1) | scsi_io_completion() {
28530 1) | blk_end_request() {
28531 1) | blk_end_bidi_request() {
28532 1) | blk_update_bidi_request() {
28533 1) | blk_update_request() {
28534 1) 0.154 us | blk_account_io_completion();
28535 1) 0.132 us | bio_advance();
28536 1) | bio_endio() {