From 1aea6434eebd25e532d2e5ddabf2733af4e1ff0b Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 9 Jan 2006 16:03:03 +0100 Subject: [SCSI] Kill the SCSI softirq handling This patch moves the SCSI softirq handling to the block layer version. There should be no functional changes. Signed-off-by: Jens Axboe --- drivers/scsi/scsi.c | 109 ++++------------------------------------------- drivers/scsi/scsi_lib.c | 36 ++++++++++++++++ drivers/scsi/scsi_priv.h | 1 + 3 files changed, 45 insertions(+), 101 deletions(-) (limited to 'drivers/scsi') diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index 180676d7115a..ee5f4dfdab14 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -69,7 +69,6 @@ #include "scsi_logging.h" static void scsi_done(struct scsi_cmnd *cmd); -static int scsi_retry_command(struct scsi_cmnd *cmd); /* * Definitions and constants. @@ -752,7 +751,7 @@ static void scsi_done(struct scsi_cmnd *cmd) * isn't running --- used by scsi_times_out */ void __scsi_done(struct scsi_cmnd *cmd) { - unsigned long flags; + struct request *rq = cmd->request; /* * Set the serial numbers back to zero @@ -763,71 +762,14 @@ void __scsi_done(struct scsi_cmnd *cmd) if (cmd->result) atomic_inc(&cmd->device->ioerr_cnt); + BUG_ON(!rq); + /* - * Next, enqueue the command into the done queue. - * It is a per-CPU queue, so we just disable local interrupts - * and need no spinlock. + * The uptodate/nbytes values don't matter, as we allow partial + * completes and thus will check this in the softirq callback */ - local_irq_save(flags); - list_add_tail(&cmd->eh_entry, &__get_cpu_var(scsi_done_q)); - raise_softirq_irqoff(SCSI_SOFTIRQ); - local_irq_restore(flags); -} - -/** - * scsi_softirq - Perform post-interrupt processing of finished SCSI commands. - * - * This is the consumer of the done queue. - * - * This is called with all interrupts enabled. This should reduce - * interrupt latency, stack depth, and reentrancy of the low-level - * drivers. - */ -static void scsi_softirq(struct softirq_action *h) -{ - int disposition; - LIST_HEAD(local_q); - - local_irq_disable(); - list_splice_init(&__get_cpu_var(scsi_done_q), &local_q); - local_irq_enable(); - - while (!list_empty(&local_q)) { - struct scsi_cmnd *cmd = list_entry(local_q.next, - struct scsi_cmnd, eh_entry); - /* The longest time any command should be outstanding is the - * per command timeout multiplied by the number of retries. - * - * For a typical command, this is 2.5 minutes */ - unsigned long wait_for - = cmd->allowed * cmd->timeout_per_command; - list_del_init(&cmd->eh_entry); - - disposition = scsi_decide_disposition(cmd); - if (disposition != SUCCESS && - time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { - sdev_printk(KERN_ERR, cmd->device, - "timing out command, waited %lus\n", - wait_for/HZ); - disposition = SUCCESS; - } - - scsi_log_completion(cmd, disposition); - switch (disposition) { - case SUCCESS: - scsi_finish_command(cmd); - break; - case NEEDS_RETRY: - scsi_retry_command(cmd); - break; - case ADD_TO_MLQUEUE: - scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); - break; - default: - if (!scsi_eh_scmd_add(cmd, 0)) - scsi_finish_command(cmd); - } - } + rq->completion_data = cmd; + blk_complete_request(rq); } /* @@ -840,7 +782,7 @@ static void scsi_softirq(struct softirq_action *h) * level drivers should not become re-entrant as a result of * this. */ -static int scsi_retry_command(struct scsi_cmnd *cmd) +int scsi_retry_command(struct scsi_cmnd *cmd) { /* * Restore the SCSI command state. @@ -1273,38 +1215,6 @@ int scsi_device_cancel(struct scsi_device *sdev, int recovery) } EXPORT_SYMBOL(scsi_device_cancel); -#ifdef CONFIG_HOTPLUG_CPU -static int scsi_cpu_notify(struct notifier_block *self, - unsigned long action, void *hcpu) -{ - int cpu = (unsigned long)hcpu; - - switch(action) { - case CPU_DEAD: - /* Drain scsi_done_q. */ - local_irq_disable(); - list_splice_init(&per_cpu(scsi_done_q, cpu), - &__get_cpu_var(scsi_done_q)); - raise_softirq_irqoff(SCSI_SOFTIRQ); - local_irq_enable(); - break; - default: - break; - } - return NOTIFY_OK; -} - -static struct notifier_block __devinitdata scsi_cpu_nb = { - .notifier_call = scsi_cpu_notify, -}; - -#define register_scsi_cpu() register_cpu_notifier(&scsi_cpu_nb) -#define unregister_scsi_cpu() unregister_cpu_notifier(&scsi_cpu_nb) -#else -#define register_scsi_cpu() -#define unregister_scsi_cpu() -#endif /* CONFIG_HOTPLUG_CPU */ - MODULE_DESCRIPTION("SCSI core"); MODULE_LICENSE("GPL"); @@ -1338,8 +1248,6 @@ static int __init init_scsi(void) INIT_LIST_HEAD(&per_cpu(scsi_done_q, i)); devfs_mk_dir("scsi"); - open_softirq(SCSI_SOFTIRQ, scsi_softirq, NULL); - register_scsi_cpu(); printk(KERN_NOTICE "SCSI subsystem initialized\n"); return 0; @@ -1367,7 +1275,6 @@ static void __exit exit_scsi(void) devfs_remove("scsi"); scsi_exit_procfs(); scsi_exit_queue(); - unregister_scsi_cpu(); } subsys_initcall(init_scsi); diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index ba93d6e66d48..00c9bf383e23 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1493,6 +1493,41 @@ static void scsi_kill_request(struct request *req, request_queue_t *q) __scsi_done(cmd); } +static void scsi_softirq_done(struct request *rq) +{ + struct scsi_cmnd *cmd = rq->completion_data; + unsigned long wait_for = cmd->allowed * cmd->timeout_per_command; + int disposition; + + INIT_LIST_HEAD(&cmd->eh_entry); + + disposition = scsi_decide_disposition(cmd); + if (disposition != SUCCESS && + time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { + sdev_printk(KERN_ERR, cmd->device, + "timing out command, waited %lus\n", + wait_for/HZ); + disposition = SUCCESS; + } + + scsi_log_completion(cmd, disposition); + + switch (disposition) { + case SUCCESS: + scsi_finish_command(cmd); + break; + case NEEDS_RETRY: + scsi_retry_command(cmd); + break; + case ADD_TO_MLQUEUE: + scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); + break; + default: + if (!scsi_eh_scmd_add(cmd, 0)) + scsi_finish_command(cmd); + } +} + /* * Function: scsi_request_fn() * @@ -1667,6 +1702,7 @@ struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); blk_queue_segment_boundary(q, shost->dma_boundary); blk_queue_issue_flush_fn(q, scsi_issue_flush_fn); + blk_queue_softirq_done(q, scsi_softirq_done); if (!shost->use_clustering) clear_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index f04e7e11f57a..14a6198cb8d2 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -44,6 +44,7 @@ extern void scsi_init_cmd_from_req(struct scsi_cmnd *cmd, struct scsi_request *sreq); extern void __scsi_release_request(struct scsi_request *sreq); extern void __scsi_done(struct scsi_cmnd *cmd); +extern int scsi_retry_command(struct scsi_cmnd *cmd); #ifdef CONFIG_SCSI_LOGGING void scsi_log_send(struct scsi_cmnd *cmd); void scsi_log_completion(struct scsi_cmnd *cmd, int disposition); -- cgit v1.2.2