[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 <axboe@suse.de>
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 180676d..ee5f4df 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 @@
* 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 @@
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 @@
* 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 @@
}
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 @@
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 @@
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 ba93d6e..00c9bf3 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1493,6 +1493,41 @@
__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 @@
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 f04e7e1..14a6198 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -44,6 +44,7 @@
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);
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index f022047..2c08fdc 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -113,7 +113,6 @@
NET_TX_SOFTIRQ,
NET_RX_SOFTIRQ,
BLOCK_SOFTIRQ,
- SCSI_SOFTIRQ,
TASKLET_SOFTIRQ
};