Re: [PATCH] cgroup: make cgroups info more readable

From: Huan Yang
Date: Fri Apr 19 2024 - 02:25:28 EST


HI jianfeng

在 2024/4/19 11:33, xiujianfeng 写道:
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Hi,

I found a discussion about this change in the email thread bellow, and
hope it helps you.
It's helpful to know why this patch not need, thank you.

https://lore.kernel.org/all/YwMwlMv%2FtK3sRXbB@xxxxxxxxxxxxxxx/#t

I have a question, that, now that only for cgroup1, when I running qemu ubuntu, I got this:

> mount | grep cgroup
> cgroup2 on /sys/fs/cgroup type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot)

Only cgroup2 mount in my system, but /proc/cgroup also worked, maybe better to disable this when only cgroup2 mounted?

On 2024/4/9 10:18, Huan Yang wrote:
The current cgroups output format is based on tabs, which
may cause misalignment of output information.

Using placeholder formatting can make the output information
more readable.

Signed-off-by: Huan Yang <link@xxxxxxxx>
---
kernel/cgroup/cgroup-v1.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 520a11cb12f4..c082a78f4c22 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -669,15 +669,16 @@ int proc_cgroupstats_show(struct seq_file *m, void *v)
struct cgroup_subsys *ss;
int i;

- seq_puts(m, "#subsys_name\thierarchy\tnum_cgroups\tenabled\n");
+ seq_printf(m, "%16s %16s %16s %16s\n", "#subsys_name", "hierarchy",
+ "num_cgroups", "enabled");
/*
* Grab the subsystems state racily. No need to add avenue to
* cgroup_mutex contention.
*/

for_each_subsys(ss, i)
- seq_printf(m, "%s\t%d\t%d\t%d\n",
- ss->legacy_name, ss->root->hierarchy_id,
+ seq_printf(m, "%16s %16d %16d %16d\n", ss->legacy_name,
+ ss->root->hierarchy_id,
atomic_read(&ss->root->nr_cgrps),
cgroup_ssid_enabled(i));