From: Christoph Lameter <cl@linux.com>
To: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: David Rientjes <rientjes@google.com>,
linux-mm@kvack.org, Eric Dumazet <eric.dumazet@gmail.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Subject: [slubll1 18/19] slub: fast release on full slab
Date: Wed, 30 Mar 2011 15:24:00 -0500 [thread overview]
Message-ID: <20110330202426.533483554@linux.com> (raw)
In-Reply-To: 20110330202342.669400887@linux.com
[-- Attachment #1: slab_alloc_fast_release --]
[-- Type: text/plain, Size: 1788 bytes --]
Make deactivation occur implicitly while checking out the current freelist.
This avoids one cmpxchg operation on a slab that is now fully in use.
Signed-off-by: Christoph Lameter <cl@linux.com>
---
mm/slub.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c 2011-03-30 14:43:57.000000000 -0500
+++ linux-2.6/mm/slub.c 2011-03-30 14:44:00.000000000 -0500
@@ -1953,9 +1953,21 @@ static void *__slab_alloc(struct kmem_ca
object = page->freelist;
counters = page->counters;
new.counters = counters;
- new.inuse = page->objects;
VM_BUG_ON(!new.frozen);
+ /*
+ * If there is no object left then we use this loop to
+ * deactivate the slab which is simple since no objects
+ * are left in the slab and therefore we do not need to
+ * put the page back onto the partial list.
+ *
+ * If there are objects left then we retrieve them
+ * and use them to refill the per cpu queue.
+ */
+
+ new.inuse = page->objects;
+ new.frozen = object != NULL;
+
} while (!cmpxchg_double_slab(s, page,
object, counters,
NULL, new.counters,
@@ -1965,8 +1977,10 @@ static void *__slab_alloc(struct kmem_ca
load_freelist:
VM_BUG_ON(!page->frozen);
- if (unlikely(!object))
+ if (unlikely(!object)) {
+ c->page = NULL;
goto new_slab;
+ }
c->freelist = get_freepointer(s, object);
--
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next prev parent reply other threads:[~2011-03-30 20:24 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-30 20:23 [slubll1 00/19] SLUB: Implement mostly lockless slowpaths Christoph Lameter
2011-03-30 20:23 ` [slubll1 01/19] percpu: Fixup __this_cpu_xchg* operations Christoph Lameter
2011-03-30 20:23 ` [slubll1 02/19] slub: get_map() function to establish map of free objects in a slab Christoph Lameter
2011-03-30 20:23 ` [slubll1 03/19] slub: Eliminate repeated use of c->page through a new page variable Christoph Lameter
2011-03-30 20:23 ` [slubll1 04/19] slub: Move node determination out of hotpath Christoph Lameter
2011-03-30 20:23 ` [slubll1 05/19] slub: Move debug handlign in __slab_free Christoph Lameter
2011-03-30 20:23 ` [slubll1 06/19] slub: Do not use frozen page flag but a bit in the page counters Christoph Lameter
2011-03-30 20:23 ` [slubll1 07/19] slub: Move page->frozen handling near where the page->freelist handling occurs Christoph Lameter
2011-03-30 20:23 ` [slubll1 08/19] x86: Add support for cmpxchg_double Christoph Lameter
2011-03-30 20:23 ` [slubll1 09/19] mm: Rearrange struct page Christoph Lameter
2011-03-30 20:23 ` [slubll1 10/19] slub: Add cmpxchg_double_slab() Christoph Lameter
2011-03-30 20:23 ` [slubll1 11/19] slub: explicit list_lock taking Christoph Lameter
2011-03-30 20:23 ` [slubll1 12/19] slub: Pass kmem_cache struct to lock and freeze slab Christoph Lameter
2011-03-30 20:23 ` [slubll1 13/19] slub: Rework allocator fastpaths Christoph Lameter
2011-03-30 20:23 ` [slubll1 14/19] slub: Invert locking and avoid slab lock Christoph Lameter
2011-03-30 20:23 ` [slubll1 15/19] slub: Disable interrupts in free_debug processing Christoph Lameter
2011-03-30 20:23 ` [slubll1 16/19] slub: Avoid disabling interrupts in free slowpath Christoph Lameter
2011-03-30 20:23 ` [slubll1 17/19] slub: Get rid of the another_slab label Christoph Lameter
2011-03-30 20:24 ` Christoph Lameter [this message]
2011-03-30 20:24 ` [slubll1 19/19] slub: Not necessary to check for empty slab on load_freelist Christoph Lameter
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