On Mon 07-08-23 20:59:59, Roman Gushchin wrote:
> On Tue, Aug 08, 2023 at 10:22:29AM +0800, xiongwei.song@xxxxxxxxxxxxx wrote:
> > From: Xiongwei Song <xiongwei.song@xxxxxxxxxxxxx>
> >
> > No any output from kmem.slabinfo, which is not friendly. Adding
> > tips for it.
> >
> > Signed-off-by: Xiongwei Song <xiongwei.song@xxxxxxxxxxxxx>
> > ---
> > mm/memcontrol.c | 6 ++----
> > 1 file changed, 2 insertions(+), 4 deletions(-)
> >
> > diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> > index e8ca4bdcb03c..58d3bd93890b 100644
> > --- a/mm/memcontrol.c
> > +++ b/mm/memcontrol.c
> > @@ -5002,10 +5002,8 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
> > #if defined(CONFIG_MEMCG_KMEM) && (defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG))
> > static int mem_cgroup_slab_show(struct seq_file *m, void *p)
> > {
> > - /*
> > - * Deprecated.
> > - * Please, take a look at tools/cgroup/memcg_slabinfo.py .
> > - */
> > + seq_puts(m, "This file is deprecated.\n"
> > + "Please use tools/cgroup/memcg_slabinfo.py, which is in kernel source.\n");
>
> It'll break the ABI.
Agreed
> The only possible option here is to use WARN_ON_ONCE(), which will print once to dmesg.
> But honestly I'm not sure we need it.
There are systems with panic_on_warn configured. I do not think we want
those to go down just becasue some random tool tries to read this file.
--
Michal Hocko
SUSE Labs
