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authorXunlei Pang <xlpang@linux.alibaba.com>2021-03-05 11:13:27 +0300
committerJens Axboe <axboe@kernel.dk>2021-03-05 21:32:15 +0300
commit4f44657d74873735e93a50eb25014721a66aac19 (patch)
treef0a94ec0d1441a685809b819c1c889b2772434f8 /block
parent66f669a272898feb1c69b770e1504aa2ec7723d1 (diff)
downloadlinux-4f44657d74873735e93a50eb25014721a66aac19.tar.xz
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')
-rw-r--r--block/blk-cgroup-rwstat.c3
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();
}