From 636620b66d5d4012c4a9c86206013964d3986c4f Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 18 Jul 2018 04:47:41 -0700 Subject: [PATCH] blkcg: Track DISCARD statistics and output them in cgroup io.stat 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 Cc: Andy Newell Cc: Michael Callahan Signed-off-by: Jens Axboe --- 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]; -- 2.30.2