From 521f3bbdba6b92582ef8047df01b156668343542 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 21 Jan 2008 20:03:12 +0100 Subject: io_context sharing - anticipatory changes changes to anticipatory io scheduler for io_context sharing Signed-off-by: Jens Axboe --- block/as-iosched.c | 34 ++++++++++++++++++++++++++++------ 1 file changed, 28 insertions(+), 6 deletions(-) (limited to 'block/as-iosched.c') diff --git a/block/as-iosched.c b/block/as-iosched.c index cb5e53b05c7..b201d16a710 100644 --- a/block/as-iosched.c +++ b/block/as-iosched.c @@ -170,9 +170,11 @@ static void free_as_io_context(struct as_io_context *aic) static void as_trim(struct io_context *ioc) { + spin_lock(&ioc->lock); if (ioc->aic) free_as_io_context(ioc->aic); ioc->aic = NULL; + spin_unlock(&ioc->lock); } /* Called when the task exits */ @@ -462,7 +464,9 @@ static void as_antic_timeout(unsigned long data) spin_lock_irqsave(q->queue_lock, flags); if (ad->antic_status == ANTIC_WAIT_REQ || ad->antic_status == ANTIC_WAIT_NEXT) { - struct as_io_context *aic = ad->io_context->aic; + struct as_io_context *aic; + spin_lock(&ad->io_context->lock); + aic = ad->io_context->aic; ad->antic_status = ANTIC_FINISHED; kblockd_schedule_work(&ad->antic_work); @@ -475,6 +479,7 @@ static void as_antic_timeout(unsigned long data) /* process not "saved" by a cooperating request */ ad->exit_no_coop = (7*ad->exit_no_coop + 256)/8; } + spin_unlock(&ad->io_context->lock); } spin_unlock_irqrestore(q->queue_lock, flags); } @@ -635,9 +640,11 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq) ioc = ad->io_context; BUG_ON(!ioc); + spin_lock(&ioc->lock); if (rq && ioc == RQ_IOC(rq)) { /* request from same process */ + spin_unlock(&ioc->lock); return 1; } @@ -646,20 +653,25 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq) * In this situation status should really be FINISHED, * however the timer hasn't had the chance to run yet. */ + spin_unlock(&ioc->lock); return 1; } aic = ioc->aic; - if (!aic) + if (!aic) { + spin_unlock(&ioc->lock); return 0; + } if (atomic_read(&aic->nr_queued) > 0) { /* process has more requests queued */ + spin_unlock(&ioc->lock); return 1; } if (atomic_read(&aic->nr_dispatched) > 0) { /* process has more requests dispatched */ + spin_unlock(&ioc->lock); return 1; } @@ -680,6 +692,7 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq) } as_update_iohist(ad, aic, rq); + spin_unlock(&ioc->lock); return 1; } @@ -688,20 +701,27 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq) if (aic->ttime_samples == 0) ad->exit_prob = (7*ad->exit_prob + 256)/8; - if (ad->exit_no_coop > 128) + if (ad->exit_no_coop > 128) { + spin_unlock(&ioc->lock); return 1; + } } if (aic->ttime_samples == 0) { - if (ad->new_ttime_mean > ad->antic_expire) + if (ad->new_ttime_mean > ad->antic_expire) { + spin_unlock(&ioc->lock); return 1; - if (ad->exit_prob * ad->exit_no_coop > 128*256) + } + if (ad->exit_prob * ad->exit_no_coop > 128*256) { + spin_unlock(&ioc->lock); return 1; + } } else if (aic->ttime_mean > ad->antic_expire) { /* the process thinks too much between requests */ + spin_unlock(&ioc->lock); return 1; } - + spin_unlock(&ioc->lock); return 0; } @@ -1255,7 +1275,9 @@ static void as_merged_requests(struct request_queue *q, struct request *req, * Don't copy here but swap, because when anext is * removed below, it must contain the unused context */ + double_spin_lock(&rioc->lock, &nioc->lock, rioc < nioc); swap_io_context(&rioc, &nioc); + double_spin_unlock(&rioc->lock, &nioc->lock, rioc < nioc); } } -- cgit v1.2.3-18-g5258