From 817e5000ebc4d448ca514db49b55073a724f8552 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Thu, 1 Dec 2011 13:32:19 +0100 Subject: [PATCH] [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 Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/cio.h | 5 ++ drivers/s390/cio/css.c | 104 +++++++++++++++++++++----------------- drivers/s390/cio/device.c | 4 +- 3 files changed, 66 insertions(+), 47 deletions(-) diff --git a/drivers/s390/cio/cio.h b/drivers/s390/cio/cio.h index 155a82bcb9e..4a1ff5c2eb8 100644 --- a/drivers/s390/cio/cio.h +++ b/drivers/s390/cio/cio.h @@ -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, }; diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c index 92d7324acb1..21908e67bf6 100644 --- a/drivers/s390/cio/css.c +++ b/drivers/s390/cio/css.c @@ -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; diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c index d734f4a0eca..47269858ecb 100644 --- a/drivers/s390/cio/device.c +++ b/drivers/s390/cio/device.c @@ -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);