Commit 1aea6434 authored by Jens Axboe's avatar Jens Axboe
Browse files

[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: default avatarJens Axboe <axboe@suse.de>
parent ff856bad
...@@ -69,7 +69,6 @@ ...@@ -69,7 +69,6 @@
#include "scsi_logging.h" #include "scsi_logging.h"
static void scsi_done(struct scsi_cmnd *cmd); static void scsi_done(struct scsi_cmnd *cmd);
static int scsi_retry_command(struct scsi_cmnd *cmd);
/* /*
* Definitions and constants. * Definitions and constants.
...@@ -752,7 +751,7 @@ static void scsi_done(struct scsi_cmnd *cmd) ...@@ -752,7 +751,7 @@ static void scsi_done(struct scsi_cmnd *cmd)
* isn't running --- used by scsi_times_out */ * isn't running --- used by scsi_times_out */
void __scsi_done(struct scsi_cmnd *cmd) void __scsi_done(struct scsi_cmnd *cmd)
{ {
unsigned long flags; struct request *rq = cmd->request;
/* /*
* Set the serial numbers back to zero * Set the serial numbers back to zero
...@@ -763,71 +762,14 @@ void __scsi_done(struct scsi_cmnd *cmd) ...@@ -763,71 +762,14 @@ void __scsi_done(struct scsi_cmnd *cmd)
if (cmd->result) if (cmd->result)
atomic_inc(&cmd->device->ioerr_cnt); atomic_inc(&cmd->device->ioerr_cnt);
BUG_ON(!rq);
/* /*
* Next, enqueue the command into the done queue. * The uptodate/nbytes values don't matter, as we allow partial
* It is a per-CPU queue, so we just disable local interrupts * completes and thus will check this in the softirq callback
* and need no spinlock.
*/ */
local_irq_save(flags); rq->completion_data = cmd;
list_add_tail(&cmd->eh_entry, &__get_cpu_var(scsi_done_q)); blk_complete_request(rq);
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);
}
}
} }
/* /*
...@@ -840,7 +782,7 @@ static void scsi_softirq(struct softirq_action *h) ...@@ -840,7 +782,7 @@ static void scsi_softirq(struct softirq_action *h)
* level drivers should not become re-entrant as a result of * level drivers should not become re-entrant as a result of
* this. * this.
*/ */
static int scsi_retry_command(struct scsi_cmnd *cmd) int scsi_retry_command(struct scsi_cmnd *cmd)
{ {
/* /*
* Restore the SCSI command state. * Restore the SCSI command state.
...@@ -1273,38 +1215,6 @@ int scsi_device_cancel(struct scsi_device *sdev, int recovery) ...@@ -1273,38 +1215,6 @@ int scsi_device_cancel(struct scsi_device *sdev, int recovery)
} }
EXPORT_SYMBOL(scsi_device_cancel); 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_DESCRIPTION("SCSI core");
MODULE_LICENSE("GPL"); MODULE_LICENSE("GPL");
...@@ -1338,8 +1248,6 @@ static int __init init_scsi(void) ...@@ -1338,8 +1248,6 @@ static int __init init_scsi(void)
INIT_LIST_HEAD(&per_cpu(scsi_done_q, i)); INIT_LIST_HEAD(&per_cpu(scsi_done_q, i));
devfs_mk_dir("scsi"); devfs_mk_dir("scsi");
open_softirq(SCSI_SOFTIRQ, scsi_softirq, NULL);
register_scsi_cpu();
printk(KERN_NOTICE "SCSI subsystem initialized\n"); printk(KERN_NOTICE "SCSI subsystem initialized\n");
return 0; return 0;
...@@ -1367,7 +1275,6 @@ static void __exit exit_scsi(void) ...@@ -1367,7 +1275,6 @@ static void __exit exit_scsi(void)
devfs_remove("scsi"); devfs_remove("scsi");
scsi_exit_procfs(); scsi_exit_procfs();
scsi_exit_queue(); scsi_exit_queue();
unregister_scsi_cpu();
} }
subsys_initcall(init_scsi); subsys_initcall(init_scsi);
......
...@@ -1493,6 +1493,41 @@ static void scsi_kill_request(struct request *req, request_queue_t *q) ...@@ -1493,6 +1493,41 @@ static void scsi_kill_request(struct request *req, request_queue_t *q)
__scsi_done(cmd); __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() * Function: scsi_request_fn()
* *
...@@ -1667,6 +1702,7 @@ struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) ...@@ -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_bounce_limit(q, scsi_calculate_bounce_limit(shost));
blk_queue_segment_boundary(q, shost->dma_boundary); blk_queue_segment_boundary(q, shost->dma_boundary);
blk_queue_issue_flush_fn(q, scsi_issue_flush_fn); blk_queue_issue_flush_fn(q, scsi_issue_flush_fn);
blk_queue_softirq_done(q, scsi_softirq_done);
if (!shost->use_clustering) if (!shost->use_clustering)
clear_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); clear_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
......
...@@ -44,6 +44,7 @@ extern void scsi_init_cmd_from_req(struct scsi_cmnd *cmd, ...@@ -44,6 +44,7 @@ extern void scsi_init_cmd_from_req(struct scsi_cmnd *cmd,
struct scsi_request *sreq); struct scsi_request *sreq);
extern void __scsi_release_request(struct scsi_request *sreq); extern void __scsi_release_request(struct scsi_request *sreq);
extern void __scsi_done(struct scsi_cmnd *cmd); extern void __scsi_done(struct scsi_cmnd *cmd);
extern int scsi_retry_command(struct scsi_cmnd *cmd);
#ifdef CONFIG_SCSI_LOGGING #ifdef CONFIG_SCSI_LOGGING
void scsi_log_send(struct scsi_cmnd *cmd); void scsi_log_send(struct scsi_cmnd *cmd);
void scsi_log_completion(struct scsi_cmnd *cmd, int disposition); void scsi_log_completion(struct scsi_cmnd *cmd, int disposition);
......
...@@ -113,7 +113,6 @@ enum ...@@ -113,7 +113,6 @@ enum
NET_TX_SOFTIRQ, NET_TX_SOFTIRQ,
NET_RX_SOFTIRQ, NET_RX_SOFTIRQ,
BLOCK_SOFTIRQ, BLOCK_SOFTIRQ,
SCSI_SOFTIRQ,
TASKLET_SOFTIRQ TASKLET_SOFTIRQ
}; };
......
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