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authorTejun Heo <tj@kernel.org>2012-04-01 14:38:44 -0700
committerTejun Heo <tj@kernel.org>2012-04-01 14:38:44 -0700
commit41b38b6d540f951c49315d8573e6f6195a6e736d (patch)
treee667cec0bba6e7678810ff0087c96547a21a45c7 /block/cfq-iosched.c
parent629ed0b10209ffc4e1d439e5508d52d5e3a090b8 (diff)
downloadop-kernel-dev-41b38b6d540f951c49315d8573e6f6195a6e736d.zip
op-kernel-dev-41b38b6d540f951c49315d8573e6f6195a6e736d.tar.gz
blkcg: cfq doesn't need per-cpu dispatch stats
blkio_group_stats_cpu is used to count dispatch stats using per-cpu counters. This is used by both blk-throtl and cfq-iosched but the sharing is rather silly. * cfq-iosched doesn't need per-cpu dispatch stats. cfq always updates those stats while holding queue_lock. * blk-throtl needs per-cpu dispatch stats but only service_bytes and serviced. It doesn't make use of sectors. This patch makes cfq add and use global stats for service_bytes, serviced and sectors, removes per-cpu sectors counter and moves per-cpu stat printing code to blk-throttle.c. Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'block/cfq-iosched.c')
-rw-r--r--block/cfq-iosched.c37
1 files changed, 10 insertions, 27 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 4991380..effd894 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -624,29 +624,12 @@ static inline void cfq_blkiocg_update_dispatch_stats(struct blkio_group *blkg,
struct blkio_policy_type *pol, uint64_t bytes,
bool direction, bool sync)
{
+ struct blkio_group_stats *stats = &blkg->pd[pol->plid]->stats;
int rw = (direction ? REQ_WRITE : 0) | (sync ? REQ_SYNC : 0);
- struct blkg_policy_data *pd = blkg->pd[pol->plid];
- struct blkio_group_stats_cpu *stats_cpu;
- unsigned long flags;
- /* If per cpu stats are not allocated yet, don't do any accounting. */
- if (pd->stats_cpu == NULL)
- return;
-
- /*
- * Disabling interrupts to provide mutual exclusion between two
- * writes on same cpu. It probably is not needed for 64bit. Not
- * optimizing that case yet.
- */
- local_irq_save(flags);
-
- stats_cpu = this_cpu_ptr(pd->stats_cpu);
-
- blkg_stat_add(&stats_cpu->sectors, bytes >> 9);
- blkg_rwstat_add(&stats_cpu->serviced, rw, 1);
- blkg_rwstat_add(&stats_cpu->service_bytes, rw, bytes);
-
- local_irq_restore(flags);
+ blkg_stat_add(&stats->sectors, bytes >> 9);
+ blkg_rwstat_add(&stats->serviced, rw, 1);
+ blkg_rwstat_add(&stats->service_bytes, rw, bytes);
}
static inline void cfq_blkiocg_update_completion_stats(struct blkio_group *blkg,
@@ -1520,20 +1503,20 @@ static struct cftype cfq_blkcg_files[] = {
{
.name = "sectors",
.private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP,
- offsetof(struct blkio_group_stats_cpu, sectors)),
- .read_seq_string = blkcg_print_cpu_stat,
+ offsetof(struct blkio_group_stats, sectors)),
+ .read_seq_string = blkcg_print_stat,
},
{
.name = "io_service_bytes",
.private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP,
- offsetof(struct blkio_group_stats_cpu, service_bytes)),
- .read_seq_string = blkcg_print_cpu_rwstat,
+ offsetof(struct blkio_group_stats, service_bytes)),
+ .read_seq_string = blkcg_print_rwstat,
},
{
.name = "io_serviced",
.private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP,
- offsetof(struct blkio_group_stats_cpu, serviced)),
- .read_seq_string = blkcg_print_cpu_rwstat,
+ offsetof(struct blkio_group_stats, serviced)),
+ .read_seq_string = blkcg_print_rwstat,
},
{
.name = "io_service_time",
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