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[S390] hibernate: directly trigger subchannel evaluation 

Using the generic css_schedule_eval to evaluate subchannels
while resuming from hibernation is very slow when used with
many devices. Provide a new evaluation trigger which exploits
css_sched_sch_todo and use this in the resume callback for
ccw devices.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Sebastian Ott 2011-12-01 13:32:19 +01:00 committed by Martin Schwidefsky
parent cfc9066bcd
commit 817e5000eb
3 changed files with 66 additions and 47 deletions
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5
drivers/s390/cio/cio.h
View File

@ -68,8 +68,13 @@ struct schib {
__u8 mda[4]; /* model dependent area */
} __attribute__ ((packed,aligned(4)));
/*
* When rescheduled, todo's with higher values will overwrite those
* with lower values.
*/
enum sch_todo {
SCH_TODO_NOTHING,
SCH_TODO_EVAL,
SCH_TODO_UNREG,
};

104
drivers/s390/cio/css.c
View File

@ -195,51 +195,6 @@ void css_sch_device_unregister(struct subchannel *sch)
}
EXPORT_SYMBOL_GPL(css_sch_device_unregister);
static void css_sch_todo(struct work_struct *work)
{
struct subchannel *sch;
enum sch_todo todo;
sch = container_of(work, struct subchannel, todo_work);
/* Find out todo. */
spin_lock_irq(sch->lock);
todo = sch->todo;
CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid,
sch->schid.sch_no, todo);
sch->todo = SCH_TODO_NOTHING;
spin_unlock_irq(sch->lock);
/* Perform todo. */
if (todo == SCH_TODO_UNREG)
css_sch_device_unregister(sch);
/* Release workqueue ref. */
put_device(&sch->dev);
}
/**
* css_sched_sch_todo - schedule a subchannel operation
* @sch: subchannel
* @todo: todo
*
* Schedule the operation identified by @todo to be performed on the slow path
* workqueue. Do nothing if another operation with higher priority is already
* scheduled. Needs to be called with subchannel lock held.
*/
void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo)
{
CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
sch->schid.ssid, sch->schid.sch_no, todo);
if (sch->todo >= todo)
return;
/* Get workqueue ref. */
if (!get_device(&sch->dev))
return;
sch->todo = todo;
if (!queue_work(cio_work_q, &sch->todo_work)) {
/* Already queued, release workqueue ref. */
put_device(&sch->dev);
}
}
static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
{
int i;
@ -466,6 +421,65 @@ static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
css_schedule_eval(schid);
}
/**
* css_sched_sch_todo - schedule a subchannel operation
* @sch: subchannel
* @todo: todo
*
* Schedule the operation identified by @todo to be performed on the slow path
* workqueue. Do nothing if another operation with higher priority is already
* scheduled. Needs to be called with subchannel lock held.
*/
void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo)
{
CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
sch->schid.ssid, sch->schid.sch_no, todo);
if (sch->todo >= todo)
return;
/* Get workqueue ref. */
if (!get_device(&sch->dev))
return;
sch->todo = todo;
if (!queue_work(cio_work_q, &sch->todo_work)) {
/* Already queued, release workqueue ref. */
put_device(&sch->dev);
}
}
static void css_sch_todo(struct work_struct *work)
{
struct subchannel *sch;
enum sch_todo todo;
int ret;
sch = container_of(work, struct subchannel, todo_work);
/* Find out todo. */
spin_lock_irq(sch->lock);
todo = sch->todo;
CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid,
sch->schid.sch_no, todo);
sch->todo = SCH_TODO_NOTHING;
spin_unlock_irq(sch->lock);
/* Perform todo. */
switch (todo) {
case SCH_TODO_NOTHING:
break;
case SCH_TODO_EVAL:
ret = css_evaluate_known_subchannel(sch, 1);
if (ret == -EAGAIN) {
spin_lock_irq(sch->lock);
css_sched_sch_todo(sch, todo);
spin_unlock_irq(sch->lock);
}
break;
case SCH_TODO_UNREG:
css_sch_device_unregister(sch);
break;
}
/* Release workqueue ref. */
put_device(&sch->dev);
}
static struct idset *slow_subchannel_set;
static spinlock_t slow_subchannel_lock;
static wait_queue_head_t css_eval_wq;

4
drivers/s390/cio/device.c
View File

@ -1868,9 +1868,9 @@ static void __ccw_device_pm_restore(struct ccw_device *cdev)
*/
cdev->private->flags.resuming = 1;
cdev->private->path_new_mask = LPM_ANYPATH;
css_schedule_eval(sch->schid);
css_sched_sch_todo(sch, SCH_TODO_EVAL);
spin_unlock_irq(sch->lock);
css_complete_work();
css_wait_for_slow_path();
/* cdev may have been moved to a different subchannel. */
sch = to_subchannel(cdev->dev.parent);