[PATCH] cgroup-v1: use find granularity format identifiers to make /proc/cgroups show pretty

From: Lin Feng
Date: Thu Jun 30 2022 - 04:26:40 EST


The listing subsys info is unaligned with the header columns and we can
make the output more intuitive to read by specifying "left alignment"
and "fixed length" format styles for seq_printf.

# cat /proc/cgroups

the output originally:

#subsys_name hierarchy num_cgroups enabled
cpuset 11 19 1
cpu 5 122 1
cpuacct 5 122 1
blkio 4 122 1
memory 10 129 1
devices 6 122 1
freezer 9 19 1
net_cls 8 19 1
perf_event 3 19 1
net_prio 8 19 1
hugetlb 7 19 1
pids 12 122 1
rdma 2 1 1

output after this patch:

#subsys_name hierarchy num_cgroups enabled
cpuset 11 19 1
cpu 5 122 1
cpuacct 5 122 1
blkio 4 122 1
memory 10 129 1
devices 6 122 1
freezer 9 19 1
net_cls 8 19 1
perf_event 3 19 1
net_prio 8 19 1
hugetlb 7 19 1
pids 12 122 1
rdma 2 1 1

Signed-off-by: Lin Feng <linf@xxxxxxxxxx>
---
kernel/cgroup/cgroup-v1.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index afc6c0e9c966..1a74b0c504aa 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -677,7 +677,7 @@ int proc_cgroupstats_show(struct seq_file *m, void *v)
*/

for_each_subsys(ss, i)
- seq_printf(m, "%s\t%d\t%d\t%d\n",
+ seq_printf(m, "%-12s\t%-10d\t%-10d\t%-d\n",
ss->legacy_name, ss->root->hierarchy_id,
atomic_read(&ss->root->nr_cgrps),
cgroup_ssid_enabled(i));
--
2.31.1