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authorTejun Heo <tj@kernel.org>2012-04-02 01:38:44 +0400
committerTejun Heo <tj@kernel.org>2012-04-02 01:38:44 +0400
commit41b38b6d540f951c49315d8573e6f6195a6e736d (patch)
treee667cec0bba6e7678810ff0087c96547a21a45c7 /block/blk-throttle.c
parent629ed0b10209ffc4e1d439e5508d52d5e3a090b8 (diff)
downloadlinux-41b38b6d540f951c49315d8573e6f6195a6e736d.tar.xz
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/blk-throttle.c')
-rw-r--r--block/blk-throttle.c31
1 files changed, 30 insertions, 1 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 5d647edc02a1..cb259bc46f43 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -582,7 +582,6 @@ static void throtl_update_dispatch_stats(struct blkio_group *blkg, u64 bytes,
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);
@@ -843,6 +842,36 @@ static void throtl_update_blkio_group_common(struct throtl_data *td,
throtl_schedule_delayed_work(td, 0);
}
+static u64 blkg_prfill_cpu_rwstat(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ struct blkg_rwstat rwstat = { }, tmp;
+ int i, cpu;
+
+ for_each_possible_cpu(cpu) {
+ struct blkio_group_stats_cpu *sc =
+ per_cpu_ptr(pd->stats_cpu, cpu);
+
+ tmp = blkg_rwstat_read((void *)sc + off);
+ for (i = 0; i < BLKG_RWSTAT_NR; i++)
+ rwstat.cnt[i] += tmp.cnt[i];
+ }
+
+ return __blkg_prfill_rwstat(sf, pd, &rwstat);
+}
+
+/* print per-cpu blkg_rwstat specified by BLKCG_STAT_PRIV() */
+static int blkcg_print_cpu_rwstat(struct cgroup *cgrp, struct cftype *cft,
+ struct seq_file *sf)
+{
+ struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgrp);
+
+ blkcg_print_blkgs(sf, blkcg, blkg_prfill_cpu_rwstat,
+ BLKCG_STAT_POL(cft->private),
+ BLKCG_STAT_OFF(cft->private), true);
+ return 0;
+}
+
static u64 blkg_prfill_conf_u64(struct seq_file *sf,
struct blkg_policy_data *pd, int off)
{