From 4f104934591ed98534b3a4c3d17d972b790e9c42 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Sun, 6 May 2007 14:50:17 -0700 Subject: [PATCH] slab allocators: Remove SLAB_CTOR_ATOMIC SLAB_CTOR atomic is never used which is no surprise since I cannot imagine that one would want to do something serious in a constructor or destructor. In particular given that the slab allocators run with interrupts disabled. Actions in constructors and destructors are by their nature very limited and usually do not go beyond initializing variables and list operations. (The i386 pgd ctor and dtors do take a spinlock in constructor and destructor..... I think that is the furthest we go at this point.) There is no flag passed to the destructor so removing SLAB_CTOR_ATOMIC also establishes a certain symmetry. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/slab.h | 1 - mm/slab.c | 17 ++--------------- mm/slub.c | 10 ++-------- 3 files changed, 4 insertions(+), 24 deletions(-) diff --git a/include/linux/slab.h b/include/linux/slab.h index 1ffe0a959cd..71829efc40b 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -34,7 +34,6 @@ typedef struct kmem_cache kmem_cache_t __deprecated; /* Flags passed to a constructor functions */ #define SLAB_CTOR_CONSTRUCTOR 0x001UL /* If not set, then deconstructor */ -#define SLAB_CTOR_ATOMIC 0x002UL /* Tell constructor it can't sleep */ /* * struct kmem_cache related prototypes diff --git a/mm/slab.c b/mm/slab.c index a877d6f3d68..52ecf7599a7 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2752,13 +2752,6 @@ static int cache_grow(struct kmem_cache *cachep, ctor_flags = SLAB_CTOR_CONSTRUCTOR; local_flags = (flags & GFP_LEVEL_MASK); - if (!(local_flags & __GFP_WAIT)) - /* - * Not allowed to sleep. Need to tell a constructor about - * this - it might need to know... - */ - ctor_flags |= SLAB_CTOR_ATOMIC; - /* Take the l3 list lock to change the colour_next on this node */ check_irq_off(); l3 = cachep->nodelists[nodeid]; @@ -3092,14 +3085,8 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, } #endif objp += obj_offset(cachep); - if (cachep->ctor && cachep->flags & SLAB_POISON) { - unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR; - - if (!(flags & __GFP_WAIT)) - ctor_flags |= SLAB_CTOR_ATOMIC; - - cachep->ctor(objp, cachep, ctor_flags); - } + if (cachep->ctor && cachep->flags & SLAB_POISON) + cachep->ctor(objp, cachep, SLAB_CTOR_CONSTRUCTOR); #if ARCH_SLAB_MINALIGN if ((u32)objp & (ARCH_SLAB_MINALIGN-1)) { printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n", diff --git a/mm/slub.c b/mm/slub.c index bd86182e595..347e44821bc 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -802,14 +802,8 @@ static void setup_object(struct kmem_cache *s, struct page *page, init_tracking(s, object); } - if (unlikely(s->ctor)) { - int mode = SLAB_CTOR_CONSTRUCTOR; - - if (!(s->flags & __GFP_WAIT)) - mode |= SLAB_CTOR_ATOMIC; - - s->ctor(object, s, mode); - } + if (unlikely(s->ctor)) + s->ctor(object, s, SLAB_CTOR_CONSTRUCTOR); } static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)