cfq-iosched: fix a kbuild regression

Alex Shi reported a kbuild regression which is about 10% performance lost.
He bisected to this commit: 3dde36ddea3e07dd025c4c1ba47edec91606fec0.
The reason is cfqq_close() can't find close cooperator. Restoring
cfq_rq_close()'s threshold to original value makes the regression go away.

Since for_preempt parameter isn't used anymore, this patch deletes it.

Reported-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Acked-by: Corrado Zoccolo <czoccolo@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 6 insertions, 5 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index dee9d9378fee..8d5a2f2f7fb9 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -47,6 +47,7 @@ static const int cfq_hist_divisor = 4;
 #define CFQ_SERVICE_SHIFT       12
 
 #define CFQQ_SEEK_THR           (sector_t)(8 * 100)
+#define CFQQ_CLOSE_THR          (sector_t)(8 * 1024)
 #define CFQQ_SECT_THR_NONROT    (sector_t)(2 * 32)
 #define CFQQ_SEEKY(cfqq)        (hweight32(cfqq->seek_history) > 32/8)
 
@@ -1660,9 +1661,9 @@ static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd,
 }
 
 static inline int cfq_rq_close(struct cfq_data *cfqd, struct cfq_queue *cfqq,
-                               struct request *rq, bool for_preempt)
+                               struct request *rq)
 {
-        return cfq_dist_from_last(cfqd, rq) <= CFQQ_SEEK_THR;
+        return cfq_dist_from_last(cfqd, rq) <= CFQQ_CLOSE_THR;
 }
 
 static struct cfq_queue *cfqq_close(struct cfq_data *cfqd,
@@ -1689,7 +1690,7 @@ static struct cfq_queue *cfqq_close(struct cfq_data *cfqd,
          * will contain the closest sector.
          */
         __cfqq = rb_entry(parent, struct cfq_queue, p_node);
-        if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq, false))
+        if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq))
                 return __cfqq;
 
         if (blk_rq_pos(__cfqq->next_rq) < sector)
@@ -1700,7 +1701,7 @@ static struct cfq_queue *cfqq_close(struct cfq_data *cfqd,
                 return NULL;
 
         __cfqq = rb_entry(node, struct cfq_queue, p_node);
-        if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq, false))
+        if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq))
                 return __cfqq;
 
         return NULL;
@@ -3103,7 +3104,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
          * if this request is as-good as one we would expect from the
          * current cfqq, let it preempt
          */
-        if (cfq_rq_close(cfqd, cfqq, rq, true))
+        if (cfq_rq_close(cfqd, cfqq, rq))
                 return true;
 
         return false;