From: Eric Dumazet <eric.dumazet@gmail.com>
To: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>,
David Rientjes <rientjes@google.com>,
"H. Peter Anvin" <hpa@zytor.com>,
linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [slubllv7 06/17] slub: Add cmpxchg_double_slab()
Date: Mon, 11 Jul 2011 21:55:00 +0200 [thread overview]
Message-ID: <1310414100.2860.6.camel@edumazet-laptop> (raw)
In-Reply-To: <20110601172615.286693377@linux.com>
Le mercredi 01 juin 2011 à 12:25 -0500, Christoph Lameter a écrit :
> pièce jointe document texte brut (cmpxchg_double_slab)
> 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 | 65 +++++++++++++++++++++++++++++++++++++++++++----
> 2 files changed, 61 insertions(+), 5 deletions(-)
>
> Index: linux-2.6/mm/slub.c
> ===================================================================
> --- linux-2.6.orig/mm/slub.c 2011-05-31 11:57:59.622937422 -0500
> +++ linux-2.6/mm/slub.c 2011-05-31 12:03:16.652935392 -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.
> @@ -170,6 +173,7 @@ static inline int kmem_cache_debug(struc
>
> /* Internal SLUB flags */
> #define __OBJECT_POISON 0x80000000UL /* Poison object */
> +#define __CMPXCHG_DOUBLE 0x40000000UL /* Use cmpxchg_double */
>
> static int kmem_size = sizeof(struct kmem_cache);
>
> @@ -338,6 +342,37 @@ 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 (s->flags & __CMPXCHG_DOUBLE) {
> + 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;
> + }
> + }
This works only on 64bit arches, where page->counters get all following
fields combined : inuse, objects, frozen, _count
On 32bit arch, I am afraid you have to disable the cmpxchg_double()
thing ?
next prev parent reply other threads:[~2011-07-11 19:55 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-01 17:25 [slubllv7 00/17] SLUB: Lockless freelists for objects V7 Christoph Lameter
2011-06-01 17:25 ` [slubllv7 01/17] slub: Push irq disable into allocate_slab() Christoph Lameter
2011-06-01 17:25 ` [slubllv7 02/17] slub: Do not use frozen page flag but a bit in the page counters Christoph Lameter
2011-06-01 17:25 ` [slubllv7 03/17] slub: Move page->frozen handling near where the page->freelist handling occurs Christoph Lameter
2011-06-01 17:25 ` [slubllv7 04/17] x86: Add support for cmpxchg_double Christoph Lameter
2011-06-09 9:53 ` Pekka Enberg
2011-06-10 15:17 ` Christoph Lameter
2011-06-11 9:50 ` Pekka Enberg
2011-06-11 17:02 ` Christoph Lameter
2011-06-14 5:49 ` Pekka Enberg
2011-06-14 8:04 ` Ingo Molnar
2011-06-14 14:04 ` Christoph Lameter
2011-06-14 15:05 ` H. Peter Anvin
2011-06-15 8:55 ` Tejun Heo
2011-06-15 14:26 ` Christoph Lameter
2011-06-15 16:39 ` Tejun Heo
2011-06-15 17:19 ` Christoph Lameter
2011-06-25 23:49 ` [tip:x86/atomic] " tip-bot for Christoph Lameter
2011-06-01 17:25 ` [slubllv7 05/17] mm: Rearrange struct page Christoph Lameter
2011-06-09 9:57 ` Pekka Enberg
2011-06-09 16:45 ` Andrew Morton
2011-06-09 17:03 ` [PATCH] checkpatch: Add a "prefer __aligned" check Joe Perches
2011-06-01 17:25 ` [slubllv7 06/17] slub: Add cmpxchg_double_slab() Christoph Lameter
2011-07-11 19:55 ` Eric Dumazet [this message]
2011-07-12 15:59 ` Christoph Lameter
2011-07-12 16:06 ` Eric Dumazet
2011-07-12 16:47 ` Christoph Lameter
2011-07-12 18:40 ` H. Peter Anvin
2011-07-12 18:53 ` Christoph Lameter
2011-07-12 20:40 ` H. Peter Anvin
2011-06-01 17:25 ` [slubllv7 07/17] slub: explicit list_lock taking Christoph Lameter
2011-06-01 17:25 ` [slubllv7 08/17] slub: Pass kmem_cache struct to lock and freeze slab Christoph Lameter
2011-06-01 17:25 ` [slubllv7 09/17] slub: Rework allocator fastpaths Christoph Lameter
2011-06-01 17:25 ` [slubllv7 10/17] slub: Invert locking and avoid slab lock Christoph Lameter
2011-06-01 17:25 ` [slubllv7 11/17] slub: Disable interrupts in free_debug processing Christoph Lameter
2011-06-01 17:25 ` [slubllv7 12/17] slub: Avoid disabling interrupts in free slowpath Christoph Lameter
2011-06-01 17:25 ` [slubllv7 13/17] slub: Get rid of the another_slab label Christoph Lameter
2011-06-01 17:25 ` [slubllv7 14/17] slub: Add statistics for the case that the current slab does not match the node Christoph Lameter
2011-06-01 17:25 ` [slubllv7 15/17] slub: fast release on full slab Christoph Lameter
2011-06-01 17:25 ` [slubllv7 16/17] slub: Not necessary to check for empty slab on load_freelist Christoph Lameter
2011-06-01 17:26 ` [slubllv7 17/17] slub: slabinfo update for cmpxchg handling Christoph Lameter
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