cfq-iosched: get rid of must_alloc flag

It's not currently used, as pointed out by
Gui Jianfeng <guijianfeng@cn.fujitsu.com>. We already check the
wait_request flag to allow an idling queue priority allocation access,
so we don't need this extra flag.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 9e6d0af..f75a54b 100644 (file)
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -186,7 +186,6 @@ enum cfqq_state_flags {
        CFQ_CFQQ_FLAG_on_rr = 0,        /* on round-robin busy list */
        CFQ_CFQQ_FLAG_wait_request,     /* waiting for a request */
        CFQ_CFQQ_FLAG_must_dispatch,    /* must be allowed a dispatch */
-       CFQ_CFQQ_FLAG_must_alloc,       /* must be allowed rq alloc */
        CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */
        CFQ_CFQQ_FLAG_fifo_expire,      /* FIFO checked in this slice */
        CFQ_CFQQ_FLAG_idle_window,      /* slice idling enabled */
@@ -213,7 +212,6 @@ static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq)             \
 CFQ_CFQQ_FNS(on_rr);
 CFQ_CFQQ_FNS(wait_request);
 CFQ_CFQQ_FNS(must_dispatch);
-CFQ_CFQQ_FNS(must_alloc);
 CFQ_CFQQ_FNS(must_alloc_slice);
 CFQ_CFQQ_FNS(fifo_expire);
 CFQ_CFQQ_FNS(idle_window);
@@ -2218,8 +2216,7 @@ static void cfq_prio_boost(struct cfq_queue *cfqq)
 
 static inline int __cfq_may_queue(struct cfq_queue *cfqq)
 {
-       if ((cfq_cfqq_wait_request(cfqq) || cfq_cfqq_must_alloc(cfqq)) &&
-           !cfq_cfqq_must_alloc_slice(cfqq)) {
+       if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) {
                cfq_mark_cfqq_must_alloc_slice(cfqq);
                return ELV_MQUEUE_MUST;
        }
@@ -2306,7 +2303,6 @@ cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask)
        }
 
        cfqq->allocated[rw]++;
-       cfq_clear_cfqq_must_alloc(cfqq);
        atomic_inc(&cfqq->ref);
 
        spin_unlock_irqrestore(q->queue_lock, flags);