blkcg: don't create "io.stat" on the root cgroup

The stat files on the root cgroup shows stats for the whole system and
usually don't contain any information which isn't available through
the usual system monitoring mechanisms.  Some controllers skip
collecting these duplicate stats to optimize cases where cgroup isn't
used and later try to emulate the result on demand.

This leads to complexities and subtle differences in the information
shown through different channels.  This is entirely unnecessary and
cgroup v2 is dropping stat files which are duplicate from all
controllers.  This patch removes "io.stat" from the root hierarchy.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: Vivek Goyal <vgoyal@redhat.com>
This commit is contained in:
Tejun Heo 2015-10-22 09:48:37 +09:00
parent e4b7037c86
commit ca0752c5e3

View File

@ -896,6 +896,7 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
struct cftype blkcg_files[] = {
{
.name = "stat",
.flags = CFTYPE_NOT_ON_ROOT,
.seq_show = blkcg_print_stat,
},
{ } /* terminate */