On Tue, Jul 17, 2018 at 08:27:53PM -0700, Andrew Morton wrote: > On Tue, 17 Jul 2018 20:24:05 -0700 Omar Sandoval <osandov@xxxxxxxxxxx> wrote: > > > > > --- a/fs/proc/kcore.c > > > > +++ b/fs/proc/kcore.c > > > > @@ -59,8 +59,8 @@ struct memelfnote > > > > }; > > > > > > > > static LIST_HEAD(kclist_head); > > > > -static DEFINE_RWLOCK(kclist_lock); > > > > -static int kcore_need_update = 1; > > > > +static DECLARE_RWSEM(kclist_lock); > > > > +static atomic_t kcore_need_update = ATOMIC_INIT(1); > > > > > > It's unclear why kcore_need_update was changed to atomic_t - it's still > > > updated under kclist_lock? > > > > Not in the hotplug notifier (kcore_callback()) anymore, so I need the > > atomic_cmpxchg() in __kcore_update_ram(). > > Well that's just > > kcore_need_update = 1; > > and turning that into an atomic_set doesn't change anything(?). > > It's not a harmful change of course, but a bit ... odd. The change from read, ..., write to cmpxchg in __kcore_update_ram() is the important part, not the change from = to atomic_set(). I needed to change that because now kcore_need_update could potentially be set again by the hotplug notifier while we're in __kcore_update_ram(). But I'll just put all of this in the commit message in v3 :) > > That could use a mention in the commit message. > > That never hurts ;)
