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| author | Xunlei Pang <xlpang@linux.alibaba.com> | 2021-03-05 16:13:27 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-03-05 11:32:15 -0700 |
| commit | 4f44657d74873735e93a50eb25014721a66aac19 (patch) | |
| tree | f0a94ec0d1441a685809b819c1c889b2772434f8 /block/blk-cgroup-rwstat.c | |
| parent | 66f669a272898feb1c69b770e1504aa2ec7723d1 (diff) | |
| download | lwn-4f44657d74873735e93a50eb25014721a66aac19.tar.gz lwn-4f44657d74873735e93a50eb25014721a66aac19.zip | |
blk-cgroup: Fix the recursive blkg rwstat
The current blkio.throttle.io_service_bytes_recursive doesn't
work correctly.
As an example, for the following blkcg hierarchy:
(Made 1GB READ in test1, 512MB READ in test2)
test
/ \
test1 test2
$ head -n 1 test/test1/blkio.throttle.io_service_bytes_recursive
8:0 Read 1073684480
$ head -n 1 test/test2/blkio.throttle.io_service_bytes_recursive
8:0 Read 537448448
$ head -n 1 test/blkio.throttle.io_service_bytes_recursive
8:0 Read 537448448
Clearly, above data of "test" reflects "test2" not "test1"+"test2".
Do the correct summary in blkg_rwstat_recursive_sum().
Signed-off-by: Xunlei Pang <xlpang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-cgroup-rwstat.c')
| -rw-r--r-- | block/blk-cgroup-rwstat.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/block/blk-cgroup-rwstat.c b/block/blk-cgroup-rwstat.c index 85d5790ac49b..3304e841df7c 100644 --- a/block/blk-cgroup-rwstat.c +++ b/block/blk-cgroup-rwstat.c @@ -109,6 +109,7 @@ void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol, lockdep_assert_held(&blkg->q->queue_lock); + memset(sum, 0, sizeof(*sum)); rcu_read_lock(); blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) { struct blkg_rwstat *rwstat; @@ -122,7 +123,7 @@ void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol, rwstat = (void *)pos_blkg + off; for (i = 0; i < BLKG_RWSTAT_NR; i++) - sum->cnt[i] = blkg_rwstat_read_counter(rwstat, i); + sum->cnt[i] += blkg_rwstat_read_counter(rwstat, i); } rcu_read_unlock(); } |