On Fri, Jun 10, 2016 at 06:39:26PM +0200, Vlastimil Babka wrote: > On 06/09/2016 08:04 PM, Mel Gorman wrote: > > Node-based reclaim requires node-based LRUs and locking. This is a > > preparation patch that just moves the lru_lock to the node so later patches > > are easier to review. It is a mechanical change but note this patch makes > > contention worse because the LRU lock is hotter and direct reclaim and > > kswapd > > can contend on the same lock even when reclaiming from different zones. > > > > Signed-off-by: Mel Gorman <mgor...@techsingularity.net> > > Acked-by: Johannes Weiner <han...@cmpxchg.org> > > Acked-by: Vlastimil Babka <vba...@suse.cz> > > One thing... > > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > index 9d71af25acf9..1e0ad06c33bd 100644 > > --- a/mm/page_alloc.c > > +++ b/mm/page_alloc.c > > @@ -5944,10 +5944,10 @@ static void __paginginit free_area_init_core(struct > > pglist_data *pgdat) > > zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100; > > #endif > > zone->name = zone_names[j]; > > + zone->zone_pgdat = pgdat; > > spin_lock_init(&zone->lock); > > - spin_lock_init(&zone->lru_lock); > > + spin_lock_init(zone_lru_lock(zone)); > > This means the same lock will be inited MAX_NR_ZONES times. Peterz told > me it's valid but weird. Probably better to do it just once, in case > lockdep/lock debugging gains some checks for that?
Ah, I thought you meant using spin_lock_init() after the lock has already been used. This is fine.
