mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-13 22:56:27 +08:00
[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>
This commit is contained in:
Jens Axboe
parent
ff856bad67
commit
1aea6434ee
@ -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);
|
||||
|
||||
@ -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);
|
||||
|
||||
@ -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);
|
||||
|
||||
@ -113,7 +113,6 @@ enum
|
||||
NET_TX_SOFTIRQ,
|
||||
NET_RX_SOFTIRQ,
|
||||
BLOCK_SOFTIRQ,
|
||||
SCSI_SOFTIRQ,
|
||||
TASKLET_SOFTIRQ
|
||||
};
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user