On Tue, Feb 09, 2021 at 05:07:07PM -0800, Yang Shi wrote: > On Tue, Feb 9, 2021 at 4:22 PM Roman Gushchin <[email protected]> wrote: > > > > On Tue, Feb 09, 2021 at 09:46:40AM -0800, Yang Shi wrote: > > > The shrinker_info is dereferenced in a couple of places via > > > rcu_dereference_protected > > > with different calling conventions, for example, using > > > mem_cgroup_nodeinfo helper > > > or dereferencing memcg->nodeinfo[nid]->shrinker_info. And the later patch > > > will add more dereference places. > > > > > > So extract the dereference into a helper to make the code more readable. > > > No > > > functional change. > > > > > > Signed-off-by: Yang Shi <[email protected]> > > > --- > > > mm/vmscan.c | 15 ++++++++++----- > > > 1 file changed, 10 insertions(+), 5 deletions(-) > > > > > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > > index 9436f9246d32..273efbf4d53c 100644 > > > --- a/mm/vmscan.c > > > +++ b/mm/vmscan.c > > > @@ -190,6 +190,13 @@ static int shrinker_nr_max; > > > #define NR_MAX_TO_SHR_MAP_SIZE(nr_max) \ > > > (DIV_ROUND_UP(nr_max, BITS_PER_LONG) * sizeof(unsigned long)) > > > > > > +static struct shrinker_info *shrinker_info_protected(struct mem_cgroup > > > *memcg, > > > + int nid) > > > +{ > > > + return > > > rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_info, > > > + lockdep_is_held(&shrinker_rwsem)); > > > +} > > > + > > > > > > I'd probably drop the "protected" suffix (because there is no unprotected > > version, > > right?). > > No, actually there is one "unprotected" call in set_shrinker_bit().
Ah, ok. Then it makes sense. Sorry. > > > > > Other than that LGTM. > > > > Acked-by: Roman Gushchin <[email protected]>
