On Wed, Apr 08, 2015 at 03:53:13PM -0700, a...@linux-foundation.org wrote: > > The patch titled > Subject: slub bulk alloc: extract objects from the per cpu slab > has been added to the -mm tree. Its filename is > slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch > > This patch should soon appear at > > http://ozlabs.org/~akpm/mmots/broken-out/slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch > and later at > > http://ozlabs.org/~akpm/mmotm/broken-out/slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch > > Before you just go and hit "reply", please: > a) Consider who else should be cc'ed > b) Prefer to cc a suitable mailing list as well > c) Ideally: find the original patch on the mailing list and do a > reply-to-all to that, adding suitable additional cc's > > *** Remember to use Documentation/SubmitChecklist when testing your code *** > > The -mm tree is included into linux-next and is updated > there every 3-4 working days > > ------------------------------------------------------ > From: Christoph Lameter <c...@linux.com> > Subject: slub bulk alloc: extract objects from the per cpu slab > > First piece: acceleration of retrieval of per cpu objects > > If we are allocating lots of objects then it is advantageous to disable > interrupts and avoid the this_cpu_cmpxchg() operation to get these objects > faster. Note that we cannot do the fast operation if debugging is > enabled. Note also that the requirement of having interrupts disabled > avoids having to do processor flag operations. > > Allocate as many objects as possible in the fast way and then fall back to > the generic implementation for the rest of the objects. > > Signed-off-by: Christoph Lameter <c...@linux.com> > Cc: Jesper Dangaard Brouer <bro...@redhat.com> > Cc: Christoph Lameter <c...@linux.com> > Cc: Pekka Enberg <penb...@kernel.org> > Cc: David Rientjes <rient...@google.com> > Cc: Joonsoo Kim <iamjoonsoo....@lge.com> > Signed-off-by: Andrew Morton <a...@linux-foundation.org> > --- > > mm/slub.c | 27 ++++++++++++++++++++++++++- > 1 file changed, 26 insertions(+), 1 deletion(-) > > diff -puN mm/slub.c~slub-bulk-alloc-extract-objects-from-the-per-cpu-slab > mm/slub.c > --- a/mm/slub.c~slub-bulk-alloc-extract-objects-from-the-per-cpu-slab > +++ a/mm/slub.c > @@ -2759,7 +2759,32 @@ EXPORT_SYMBOL(kmem_cache_free_bulk); > bool kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, > void **p) > { > - return kmem_cache_alloc_bulk(s, flags, size, p); > + if (!kmem_cache_debug(s)) { > + struct kmem_cache_cpu *c; > + > + /* Drain objects in the per cpu slab */ > + local_irq_disable(); > + c = this_cpu_ptr(s->cpu_slab); > + > + while (size) { > + void *object = c->freelist; > + > + if (!object) > + break; > + > + c->freelist = get_freepointer(s, object); > + *p++ = object; > + size--; > + > + if (unlikely(flags & __GFP_ZERO)) > + memset(object, 0, s->object_size);
Ahh... and, how about doing memset after irq is enabled? Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
