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 10/19] slub: Add cmpxchg_double_slab()
Date: Wed, 30 Mar 2011 15:23:52 -0500 [thread overview]
Message-ID: <20110330202421.349168617@linux.com> (raw)
In-Reply-To: 20110330202342.669400887@linux.com
[-- Attachment #1: cmpxchg_double_slab --]
[-- Type: text/plain, Size: 3429 bytes --]
Add a function that operates on the second doubleword in the page struct
and manipulates the object counters, the freelist and the frozen attribute.
Signed-off-by: Christoph Lameter <cl@linux.com>
---
include/linux/slub_def.h | 1 +
mm/slub.c | 38 ++++++++++++++++++++++++++++++++++++++
2 files changed, 39 insertions(+)
Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c 2011-03-30 14:34:59.000000000 -0500
+++ linux-2.6/mm/slub.c 2011-03-30 14:42:52.000000000 -0500
@@ -131,6 +131,9 @@ static inline int kmem_cache_debug(struc
/* Enable to test recovery from slab corruption on boot */
#undef SLUB_RESILIENCY_TEST
+/* Enable to log cmpxchg failures */
+#undef SLUB_DEBUG_CMPXCHG
+
/*
* Mininum number of partial slabs. These will be left on the partial
* lists even if they are empty. kmem_cache_shrink may reclaim them.
@@ -326,6 +329,37 @@ static inline int oo_objects(struct kmem
return x.x & OO_MASK;
}
+static inline bool cmpxchg_double_slab(struct kmem_cache *s, struct page *page,
+ void *freelist_old, unsigned long counters_old,
+ void *freelist_new, unsigned long counters_new,
+ const char *n)
+{
+#ifdef CONFIG_CMPXCHG_DOUBLE
+ if (!kmem_cache_debug(s)) {
+ if (cmpxchg_double(&page->freelist,
+ freelist_old, counters_old,
+ freelist_new, counters_new))
+ return 1;
+ } else
+#endif
+ {
+ if (page->freelist == freelist_old && page->counters == counters_old) {
+ page->freelist = freelist_new;
+ page->counters = counters_new;
+ return 1;
+ }
+ }
+
+ cpu_relax();
+ stat(s, CMPXCHG_DOUBLE_FAIL);
+
+#ifdef SLUB_DEBUG_CMPXCHG
+ printk(KERN_INFO "%s %s: cmpxchg double redo ", n, s->name);
+#endif
+
+ return 0;
+}
+
/*
* Determine a map of object in use on a page.
*
@@ -4535,6 +4569,8 @@ STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate
STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
STAT_ATTR(ORDER_FALLBACK, order_fallback);
+STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL, cmpxchg_double_cpu_fail);
+STAT_ATTR(CMPXCHG_DOUBLE_FAIL, cmpxchg_double_fail);
#endif
static struct attribute *slab_attrs[] = {
@@ -4592,6 +4628,8 @@ static struct attribute *slab_attrs[] =
&deactivate_to_tail_attr.attr,
&deactivate_remote_frees_attr.attr,
&order_fallback_attr.attr,
+ &cmpxchg_double_fail_attr.attr,
+ &cmpxchg_double_cpu_fail_attr.attr,
#endif
#ifdef CONFIG_FAILSLAB
&failslab_attr.attr,
Index: linux-2.6/include/linux/slub_def.h
===================================================================
--- linux-2.6.orig/include/linux/slub_def.h 2011-03-30 14:34:59.000000000 -0500
+++ linux-2.6/include/linux/slub_def.h 2011-03-30 14:35:01.000000000 -0500
@@ -33,6 +33,7 @@ enum stat_item {
DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
ORDER_FALLBACK, /* Number of times fallback was necessary */
CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
+ CMPXCHG_DOUBLE_FAIL, /* Number of times that cmpxchg double did not match */
NR_SLUB_STAT_ITEMS };
struct kmem_cache_cpu {
--
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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 ` Christoph Lameter [this message]
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 ` [slubll1 18/19] slub: fast release on full slab Christoph Lameter
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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