as: fix antic_expire check

Fix units mismatch (jiffies vs msecs) in as-iosched.c, spotted by Xiaoning
Ding <dingxn@cse.ohio-state.edu>.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/block/as-iosched.c b/block/as-iosched.c
index ef12627..640aa83 100644 (file)
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -569,7 +569,7 @@ static void as_update_iohist(struct as_data *ad, struct as_io_context *aic,
 static int as_close_req(struct as_data *ad, struct as_io_context *aic,
                        struct request *rq)
 {
-       unsigned long delay;    /* milliseconds */
+       unsigned long delay;    /* jiffies */
        sector_t last = ad->last_sector[ad->batch_data_dir];
        sector_t next = rq->sector;
        sector_t delta; /* acceptable close offset (in sectors) */
@@ -578,11 +578,11 @@ static int as_close_req(struct as_data *ad, struct as_io_context *aic,
        if (ad->antic_status == ANTIC_OFF || !ad->ioc_finished)
                delay = 0;
        else
-               delay = ((jiffies - ad->antic_start) * 1000) / HZ;
+               delay = jiffies - ad->antic_start;
 
        if (delay == 0)
                delta = 8192;
-       else if (delay <= 20 && delay <= ad->antic_expire)
+       else if (delay <= (20 * HZ / 1000) && delay <= ad->antic_expire)
                delta = 8192 << delay;
        else
                return 1;