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authorLinus Torvalds <torvalds@linux-foundation.org>2010-02-11 14:07:00 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2010-02-11 14:07:00 -0800
commitffaa60d5fe1d30b618b0feb22c79486c26a16ea0 (patch)
treee4c2d26c7565c7cee36065753db09467a27e0339
parentefa82bab8e3509bb2c4a8044de5909b8bab96cfd (diff)
parent531c2dc70d339c5dfa8c3eb628c3459dc6f3a075 (diff)
downloadlinux-linaro-stable-ffaa60d5fe1d30b618b0feb22c79486c26a16ea0.tar.gz
Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: cciss: Make cciss_seq_show handle holes in the h->drv[] array cfq-iosched: split seeky coop queues after one slice
-rw-r--r--block/cfq-iosched.c49
-rw-r--r--drivers/block/cciss.c3
2 files changed, 19 insertions, 33 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 17b768d0d42f..023f4e69a337 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -42,16 +42,13 @@ static const int cfq_hist_divisor = 4;
*/
#define CFQ_MIN_TT (2)
-/*
- * Allow merged cfqqs to perform this amount of seeky I/O before
- * deciding to break the queues up again.
- */
-#define CFQQ_COOP_TOUT (HZ)
-
#define CFQ_SLICE_SCALE (5)
#define CFQ_HW_QUEUE_MIN (5)
#define CFQ_SERVICE_SHIFT 12
+#define CFQQ_SEEK_THR 8 * 1024
+#define CFQQ_SEEKY(cfqq) ((cfqq)->seek_mean > CFQQ_SEEK_THR)
+
#define RQ_CIC(rq) \
((struct cfq_io_context *) (rq)->elevator_private)
#define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elevator_private2)
@@ -137,7 +134,6 @@ struct cfq_queue {
u64 seek_total;
sector_t seek_mean;
sector_t last_request_pos;
- unsigned long seeky_start;
pid_t pid;
@@ -314,6 +310,7 @@ enum cfqq_state_flags {
CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */
CFQ_CFQQ_FLAG_sync, /* synchronous queue */
CFQ_CFQQ_FLAG_coop, /* cfqq is shared */
+ CFQ_CFQQ_FLAG_split_coop, /* shared cfqq will be splitted */
CFQ_CFQQ_FLAG_deep, /* sync cfqq experienced large depth */
CFQ_CFQQ_FLAG_wait_busy, /* Waiting for next request */
};
@@ -342,6 +339,7 @@ CFQ_CFQQ_FNS(prio_changed);
CFQ_CFQQ_FNS(slice_new);
CFQ_CFQQ_FNS(sync);
CFQ_CFQQ_FNS(coop);
+CFQ_CFQQ_FNS(split_coop);
CFQ_CFQQ_FNS(deep);
CFQ_CFQQ_FNS(wait_busy);
#undef CFQ_CFQQ_FNS
@@ -1566,6 +1564,15 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
cfq_clear_cfqq_wait_busy(cfqq);
/*
+ * If this cfqq is shared between multiple processes, check to
+ * make sure that those processes are still issuing I/Os within
+ * the mean seek distance. If not, it may be time to break the
+ * queues apart again.
+ */
+ if (cfq_cfqq_coop(cfqq) && CFQQ_SEEKY(cfqq))
+ cfq_mark_cfqq_split_coop(cfqq);
+
+ /*
* store what was left of this slice, if the queue idled/timed out
*/
if (timed_out && !cfq_cfqq_slice_new(cfqq)) {
@@ -1663,9 +1670,6 @@ static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd,
return cfqd->last_position - blk_rq_pos(rq);
}
-#define CFQQ_SEEK_THR 8 * 1024
-#define CFQQ_SEEKY(cfqq) ((cfqq)->seek_mean > CFQQ_SEEK_THR)
-
static inline int cfq_rq_close(struct cfq_data *cfqd, struct cfq_queue *cfqq,
struct request *rq, bool for_preempt)
{
@@ -3000,19 +3004,6 @@ cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_queue *cfqq,
total = cfqq->seek_total + (cfqq->seek_samples/2);
do_div(total, cfqq->seek_samples);
cfqq->seek_mean = (sector_t)total;
-
- /*
- * If this cfqq is shared between multiple processes, check to
- * make sure that those processes are still issuing I/Os within
- * the mean seek distance. If not, it may be time to break the
- * queues apart again.
- */
- if (cfq_cfqq_coop(cfqq)) {
- if (CFQQ_SEEKY(cfqq) && !cfqq->seeky_start)
- cfqq->seeky_start = jiffies;
- else if (!CFQQ_SEEKY(cfqq))
- cfqq->seeky_start = 0;
- }
}
/*
@@ -3453,14 +3444,6 @@ cfq_merge_cfqqs(struct cfq_data *cfqd, struct cfq_io_context *cic,
return cic_to_cfqq(cic, 1);
}
-static int should_split_cfqq(struct cfq_queue *cfqq)
-{
- if (cfqq->seeky_start &&
- time_after(jiffies, cfqq->seeky_start + CFQQ_COOP_TOUT))
- return 1;
- return 0;
-}
-
/*
* Returns NULL if a new cfqq should be allocated, or the old cfqq if this
* was the last process referring to said cfqq.
@@ -3469,9 +3452,9 @@ static struct cfq_queue *
split_cfqq(struct cfq_io_context *cic, struct cfq_queue *cfqq)
{
if (cfqq_process_refs(cfqq) == 1) {
- cfqq->seeky_start = 0;
cfqq->pid = current->pid;
cfq_clear_cfqq_coop(cfqq);
+ cfq_clear_cfqq_split_coop(cfqq);
return cfqq;
}
@@ -3510,7 +3493,7 @@ new_queue:
/*
* If the queue was seeky for too long, break it apart.
*/
- if (cfq_cfqq_coop(cfqq) && should_split_cfqq(cfqq)) {
+ if (cfq_cfqq_coop(cfqq) && cfq_cfqq_split_coop(cfqq)) {
cfq_log_cfqq(cfqd, cfqq, "breaking apart cfqq");
cfqq = split_cfqq(cic, cfqq);
if (!cfqq)
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 873e594860d3..9291614ac6b7 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -337,6 +337,9 @@ static int cciss_seq_show(struct seq_file *seq, void *v)
if (*pos > h->highest_lun)
return 0;
+ if (drv == NULL) /* it's possible for h->drv[] to have holes. */
+ return 0;
+
if (drv->heads == 0)
return 0;