From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> I found this useful to have in my testing. I would like to have it available for a bit, at least until other folks have had a chance to do some testing with it. We should probably just pull the help text and the description out of this so that folks are not prompted for it instead of ripping it out entirely. Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> --- linux.git-davehans/include/linux/mm_types.h | 3 +-- linux.git-davehans/init/Kconfig | 2 +- linux.git-davehans/mm/slub.c | 9 +++------ 3 files changed, 5 insertions(+), 9 deletions(-) diff -puN include/linux/mm_types.h~abstract-out-slub-double-cmpxchg-operation include/linux/mm_types.h --- linux.git/include/linux/mm_types.h~abstract-out-slub-double-cmpxchg-operation 2014-01-02 15:28:04.382877603 -0800 +++ linux.git-davehans/include/linux/mm_types.h 2014-01-02 15:28:04.391878008 -0800 @@ -38,8 +38,7 @@ struct slub_data { * all of the above counters in one chunk. * The actual counts are never accessed via this. */ -#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \ - defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE) +#if defined(CONFIG_SLUB_ATTEMPT_CMPXCHG_DOUBLE) unsigned long counters; #else /* diff -puN init/Kconfig~abstract-out-slub-double-cmpxchg-operation init/Kconfig --- linux.git/init/Kconfig~abstract-out-slub-double-cmpxchg-operation 2014-01-02 15:28:04.384877693 -0800 +++ linux.git-davehans/init/Kconfig 2014-01-02 15:28:04.392878053 -0800 @@ -841,7 +841,7 @@ config SLUB_CPU_PARTIAL config SLUB_ATTEMPT_CMPXCHG_DOUBLE default y - depends on SLUB && HAVE_CMPXCHG_DOUBLE + depends on SLUB && HAVE_CMPXCHG_DOUBLE && HAVE_ALIGNED_STRUCT_PAGE bool "SLUB: attempt to use double-cmpxchg operations" help Some CPUs support instructions that let you do a large double-word diff -puN mm/slub.c~abstract-out-slub-double-cmpxchg-operation mm/slub.c --- linux.git/mm/slub.c~abstract-out-slub-double-cmpxchg-operation 2014-01-02 15:28:04.386877783 -0800 +++ linux.git-davehans/mm/slub.c 2014-01-02 15:28:04.394878143 -0800 @@ -368,8 +368,7 @@ static inline bool __cmpxchg_double_slab const char *n) { VM_BUG_ON(!irqs_disabled()); -#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \ - defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE) +#if defined(CONFIG_SLUB_ATTEMPT_CMPXCHG_DOUBLE) if (s->flags & __CMPXCHG_DOUBLE) { if (cmpxchg_double(&slub_data(page)->freelist, &slub_data(page)->counters, freelist_old, counters_old, @@ -404,8 +403,7 @@ static inline bool cmpxchg_double_slab(s void *freelist_new, unsigned long counters_new, const char *n) { -#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \ - defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE) +#if defined(CONFIG_SLUB_ATTEMPT_CMPXCHG_DOUBLE) if (s->flags & __CMPXCHG_DOUBLE) { if (cmpxchg_double(&slub_data(page)->freelist, &slub_data(page)->counters, freelist_old, counters_old, @@ -3085,8 +3083,7 @@ static int kmem_cache_open(struct kmem_c } } -#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \ - defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE) +#if defined(CONFIG_SLUB_ATTEMPT_CMPXCHG_DOUBLE) if (system_has_cmpxchg_double() && (s->flags & SLAB_DEBUG_FLAGS) == 0) /* Enable fast mode */ s->flags |= __CMPXCHG_DOUBLE; _ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>