Add tracking of REQ_OP_DISCARD ios to the per-cgroup io.stat. Two
fields, dbytes and dios, to respectively count the total bytes and
number of discards are added.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Cc: Andy Newell <newella@xxxxxx>
Cc: Michael Callahan <michaelcallahan@xxxxxx>
---
Documentation/admin-guide/cgroup-v2.rst | 10 ++++++----
block/blk-cgroup.c | 13 +++++++++----
include/linux/blk-cgroup.h | 5 ++++-
3 files changed, 19 insertions(+), 9 deletions(-)
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 569ce27b85e5..3afe10fa82bc 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -1317,17 +1317,19 @@ IO Interface Files
Lines are keyed by $MAJ:$MIN device numbers and not ordered.
The following nested keys are defined.
- ====== ===================
+ ====== =====================
rbytes Bytes read
wbytes Bytes written
rios Number of read IOs
wios Number of write IOs
- ====== ===================
+ dbytes Bytes discarded
+ dios Number of discard IOs
+ ====== =====================
An example read output follows:
- 8:16 rbytes=1459200 wbytes=314773504 rios=192 wios=353
- 8:0 rbytes=90430464 wbytes=299008000 rios=8950 wios=1252
+ 8:16 rbytes=1459200 wbytes=314773504 rios=192 wios=353 dbytes=0 dios=0
+ 8:0 rbytes=90430464 wbytes=299008000 rios=8950 wios=1252 dbytes=50331648 dios=3021
io.weight
A read-write flat-keyed file which exists on non-root cgroups.
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 7e2c19ce1a08..1942357d7165 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -567,6 +567,7 @@ u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
[BLKG_RWSTAT_WRITE] = "Write",
[BLKG_RWSTAT_SYNC] = "Sync",
[BLKG_RWSTAT_ASYNC] = "Async",
+ [BLKG_RWSTAT_DISCARD] = "Discard",
};
const char *dname = blkg_dev_name(pd->blkg);
u64 v;
@@ -580,7 +581,8 @@ u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
(unsigned long long)atomic64_read(&rwstat->aux_cnt[i]));
v = atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_READ]) +
- atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_WRITE]);
+ atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_WRITE]) +
+ atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_DISCARD]);
seq_printf(sf, "%s Total %llu\n", dname, (unsigned long long)v);
return v;
}
@@ -959,7 +961,7 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
const char *dname;
char *buf;
struct blkg_rwstat rwstat;
- u64 rbytes, wbytes, rios, wios;
+ u64 rbytes, wbytes, rios, wios, dbytes, dios;
size_t size = seq_get_buf(sf, &buf), off = 0;
int i;
bool has_stats = false;
@@ -982,19 +984,22 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
offsetof(struct blkcg_gq, stat_bytes));
rbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_READ]);
wbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_WRITE]);
+ dbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_DISCARD]);
rwstat = blkg_rwstat_recursive_sum(blkg, NULL,
offsetof(struct blkcg_gq, stat_ios));
rios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_READ]);
wios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_WRITE]);
+ dios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_DISCARD]);
spin_unlock_irq(blkg->q->queue_lock);
if (rbytes || wbytes || rios || wios) {
has_stats = true;
off += scnprintf(buf+off, size-off,
- "rbytes=%llu wbytes=%llu rios=%llu wios=%llu",
- rbytes, wbytes, rios, wios);
+ "rbytes=%llu wbytes=%llu rios=%llu wios=%llu dbytes=%llu dios=%llu",
+ rbytes, wbytes, rios, wios,
+ dbytes, dios);
}
if (!blkcg_debug_stats)
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index de57de4831d5..3bed5e02a873 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -35,6 +35,7 @@ enum blkg_rwstat_type {
BLKG_RWSTAT_WRITE,
BLKG_RWSTAT_SYNC,
BLKG_RWSTAT_ASYNC,
+ BLKG_RWSTAT_DISCARD,
BLKG_RWSTAT_NR,
BLKG_RWSTAT_TOTAL = BLKG_RWSTAT_NR,
@@ -649,7 +650,9 @@ static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat,
{
struct percpu_counter *cnt;
- if (op_is_write(op))
+ if (op_is_discard(op))
+ cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_DISCARD];
+ else if (op_is_write(op))
cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_WRITE];
else
cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_READ];
--
2.17.1
--
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