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authorJens Axboe <axboe@suse.de>2006-07-19 05:10:01 +0200
committerJens Axboe <axboe@nelson.home.kernel.dk>2006-09-30 20:29:37 +0200
commite4313dd423148fa729571b50c06cbc0bedf5c494 (patch)
tree7524020d6d822b06aa433c1252a4926b91a8b328 /block/as-iosched.c
parent4a893e837bb470867d74c05d6c6b97bba5a96185 (diff)
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[PATCH] as-iosched: use new io context counting mechanism
It's ok if the read path is a lot more costly, as long as inc/dec is really cheap. The inc/dec will happen for each created/freed io context, while the reading only happens when a disk queue exits. Signed-off-by: Jens Axboe <axboe@suse.de>
Diffstat (limited to 'block/as-iosched.c')
-rw-r--r--block/as-iosched.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/block/as-iosched.c b/block/as-iosched.c
index 66015bc79e6..8e1fef1eafc 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -149,7 +149,7 @@ enum arq_state {
#define RQ_STATE(rq) ((enum arq_state)(rq)->elevator_private2)
#define RQ_SET_STATE(rq, state) ((rq)->elevator_private2 = (void *) state)
-static atomic_t ioc_count = ATOMIC_INIT(0);
+static DEFINE_PER_CPU(unsigned long, ioc_count);
static struct completion *ioc_gone;
static void as_move_to_dispatch(struct as_data *ad, struct request *rq);
@@ -163,7 +163,8 @@ static void as_antic_stop(struct as_data *ad);
static void free_as_io_context(struct as_io_context *aic)
{
kfree(aic);
- if (atomic_dec_and_test(&ioc_count) && ioc_gone)
+ elv_ioc_count_dec(ioc_count);
+ if (ioc_gone && !elv_ioc_count_read(ioc_count))
complete(ioc_gone);
}
@@ -199,7 +200,7 @@ static struct as_io_context *alloc_as_io_context(void)
ret->seek_total = 0;
ret->seek_samples = 0;
ret->seek_mean = 0;
- atomic_inc(&ioc_count);
+ elv_ioc_count_inc(ioc_count);
}
return ret;
@@ -1484,7 +1485,7 @@ static void __exit as_exit(void)
ioc_gone = &all_gone;
/* ioc_gone's update must be visible before reading ioc_count */
smp_wmb();
- if (atomic_read(&ioc_count))
+ if (elv_ioc_count_read(ioc_count))
wait_for_completion(ioc_gone);
synchronize_rcu();
}