Messages in this thread | | | From | Xiongwei Song <> | Date | Mon, 28 Jun 2021 11:19:06 +0800 | Subject | Re: [PATCH] locking/lockdep: Fix meaningless usages output of lock classes |
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Please ignore this patch, it's not good. I will improve it.
Regards, Xiongwei
On Sun, Jun 27, 2021 at 10:23 PM Xiongwei Song <sxwjean@me.com> wrote: > > From: Xiongwei Song <sxwjean@gmail.com> > > When enabling CONFIG_LOCK_STAT, then CONFIG_LOCKDEP is forcedly enabled. > We can get output from /proc/lockdep, which currently includes usages of > classes. But the usages of classes are meaningless, see the output > below: > > / # cat /proc/lockdep > all lock classes: > ffffffff9af63350 ....: cgroup_mutex > > ffffffff9af54eb8 ....: (console_sem).lock > > ffffffff9af54e60 ....: console_lock > > ffffffff9ae74c38 ....: console_owner_lock > > ffffffff9ae74c80 ....: console_owner > > ffffffff9ae66e60 ....: cpu_hotplug_lock > > Only one usage context for each lock, this is because each usage is only > changed in mark_lock() that is in CONFIG_PROVE_LOCKING defined section, > however in the test situation, it's not. > > The fix is to move the usages reading and seq_print from > CONFIG_PROVE_LOCKING undefined setcion to it defined section. > > Signed-off-by: Xiongwei Song <sxwjean@gmail.com> > --- > kernel/locking/lockdep_proc.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c > index 806978314496..1b1103ee7dc6 100644 > --- a/kernel/locking/lockdep_proc.c > +++ b/kernel/locking/lockdep_proc.c > @@ -73,10 +73,11 @@ static int l_show(struct seq_file *m, void *v) > #ifdef CONFIG_PROVE_LOCKING > seq_printf(m, " FD:%5ld", lockdep_count_forward_deps(class)); > seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class)); > -#endif > > get_usage_chars(class, usage); > seq_printf(m, " %s", usage); > +#endif > + > > seq_printf(m, ": "); > print_name(m, class); > -- > 2.30.2 >
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