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[SCSI] Kill the SCSI softirq handling

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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>
This commit is contained in:
Jens Axboe
2006-01-09 16:03:03 +01:00
parent ff856bad67
commit 1aea6434ee
4 changed files with 45 additions and 102 deletions
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drivers/scsi/scsi.c
+8 -101
View File
@@ -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);