On Fri, Jun 06, 2014 at 05:22:44PM +0400, Vladimir Davydov wrote: > Since a dead memcg cache is destroyed only after the last slab allocated > to it is freed, we must disable caching of empty slabs for such caches, > otherwise they will be hanging around forever. > > This patch makes SLUB discard dead memcg caches' slabs as soon as they > become empty. To achieve that, it disables per cpu partial lists for > dead caches (see put_cpu_partial) and forbids keeping empty slabs on per > node partial lists by setting cache's min_partial to 0 on > kmem_cache_shrink, which is always called on memcg offline (see > memcg_unregister_all_caches). > > Signed-off-by: Vladimir Davydov <[email protected]> > Thanks-to: Joonsoo Kim <[email protected]> > --- > mm/slub.c | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/mm/slub.c b/mm/slub.c > index e46d6abe8a68..1dad7e2c586a 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -2015,6 +2015,8 @@ static void unfreeze_partials(struct kmem_cache *s, > #endif > } > > +static void flush_all(struct kmem_cache *s); > + > /* > * Put a page that was just frozen (in __slab_free) into a partial page > * slot if available. This is done without interrupts disabled and without > @@ -2064,6 +2066,21 @@ static void put_cpu_partial(struct kmem_cache *s, > struct page *page, int drain) > > } while (this_cpu_cmpxchg(s->cpu_slab->partial, oldpage, page) > != oldpage); > + > + if (memcg_cache_dead(s)) { > + bool done = false; > + unsigned long flags; > + > + local_irq_save(flags); > + if (this_cpu_read(s->cpu_slab->partial) == page) { > + unfreeze_partials(s, this_cpu_ptr(s->cpu_slab)); > + done = true; > + } > + local_irq_restore(flags); > + > + if (!done) > + flush_all(s); > + }
Now, slab_free() is non-preemptable so flush_all() isn't needed. Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
