From 729bd0b74ce9ac6c829109052fcd565f5c366ca5 Mon Sep 17 00:00:00 2001 From: Pekka Enberg Date: Fri, 23 Jun 2006 02:03:05 -0700 Subject: [PATCH] slab: extract cache_free_alien from __cache_free Move alien object freeing to cache_free_alien() to reduce #ifdef clutter in __cache_free(). Signed-off-by: Pekka Enberg Acked-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab.c | 77 ++++++++++++++++++++++++++++++++++----------------------------- 1 file changed, 42 insertions(+), 35 deletions(-) (limited to 'mm/slab.c') diff --git a/mm/slab.c b/mm/slab.c index f1b644eb39d..bf05ea900ce 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -1024,6 +1024,40 @@ static void drain_alien_cache(struct kmem_cache *cachep, } } } + +static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) +{ + struct slab *slabp = virt_to_slab(objp); + int nodeid = slabp->nodeid; + struct kmem_list3 *l3; + struct array_cache *alien = NULL; + + /* + * Make sure we are not freeing a object from another node to the array + * cache on this cpu. + */ + if (likely(slabp->nodeid == numa_node_id())) + return 0; + + l3 = cachep->nodelists[numa_node_id()]; + STATS_INC_NODEFREES(cachep); + if (l3->alien && l3->alien[nodeid]) { + alien = l3->alien[nodeid]; + spin_lock(&alien->lock); + if (unlikely(alien->avail == alien->limit)) { + STATS_INC_ACOVERFLOW(cachep); + __drain_alien_cache(cachep, alien, nodeid); + } + alien->entry[alien->avail++] = objp; + spin_unlock(&alien->lock); + } else { + spin_lock(&(cachep->nodelists[nodeid])->list_lock); + free_block(cachep, &objp, 1, nodeid); + spin_unlock(&(cachep->nodelists[nodeid])->list_lock); + } + return 1; +} + #else #define drain_alien_cache(cachep, alien) do { } while (0) @@ -1038,6 +1072,11 @@ static inline void free_alien_cache(struct array_cache **ac_ptr) { } +static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) +{ + return 0; +} + #endif static int cpuup_callback(struct notifier_block *nfb, @@ -3087,41 +3126,9 @@ static inline void __cache_free(struct kmem_cache *cachep, void *objp) check_irq_off(); objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0)); - /* Make sure we are not freeing a object from another - * node to the array cache on this cpu. - */ -#ifdef CONFIG_NUMA - { - struct slab *slabp; - slabp = virt_to_slab(objp); - if (unlikely(slabp->nodeid != numa_node_id())) { - struct array_cache *alien = NULL; - int nodeid = slabp->nodeid; - struct kmem_list3 *l3; - - l3 = cachep->nodelists[numa_node_id()]; - STATS_INC_NODEFREES(cachep); - if (l3->alien && l3->alien[nodeid]) { - alien = l3->alien[nodeid]; - spin_lock(&alien->lock); - if (unlikely(alien->avail == alien->limit)) { - STATS_INC_ACOVERFLOW(cachep); - __drain_alien_cache(cachep, - alien, nodeid); - } - alien->entry[alien->avail++] = objp; - spin_unlock(&alien->lock); - } else { - spin_lock(&(cachep->nodelists[nodeid])-> - list_lock); - free_block(cachep, &objp, 1, nodeid); - spin_unlock(&(cachep->nodelists[nodeid])-> - list_lock); - } - return; - } - } -#endif + if (cache_free_alien(cachep, objp)) + return; + if (likely(ac->avail < ac->limit)) { STATS_INC_FREEHIT(cachep); ac->entry[ac->avail++] = objp; -- cgit v1.2.3-70-g09d2 From 4776874ff096cd410382c0eca5d75f69c9dfa58f Mon Sep 17 00:00:00 2001 From: Pekka Enberg Date: Fri, 23 Jun 2006 02:03:07 -0700 Subject: [PATCH] slab: page mapping cleanup Clean up slab allocator page mapping a bit. The memory allocated for a slab is physically contiguous so it is okay to assume struct pages are too so kill the long-standing comment. Furthermore, rename set_slab_attr to slab_map_pages and add a comment explaining why its needed. Signed-off-by: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) (limited to 'mm/slab.c') diff --git a/mm/slab.c b/mm/slab.c index bf05ea900ce..a94cf0fea8a 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2499,23 +2499,28 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp, slabp->inuse--; } -static void set_slab_attr(struct kmem_cache *cachep, struct slab *slabp, - void *objp) +/* + * Map pages beginning at addr to the given cache and slab. This is required + * for the slab allocator to be able to lookup the cache and slab of a + * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging. + */ +static void slab_map_pages(struct kmem_cache *cache, struct slab *slab, + void *addr) { - int i; + int nr_pages; struct page *page; - /* Nasty!!!!!! I hope this is OK. */ - page = virt_to_page(objp); + page = virt_to_page(addr); - i = 1; + nr_pages = 1; if (likely(!PageCompound(page))) - i <<= cachep->gfporder; + nr_pages <<= cache->gfporder; + do { - page_set_cache(page, cachep); - page_set_slab(page, slabp); + page_set_cache(page, cache); + page_set_slab(page, slab); page++; - } while (--i); + } while (--nr_pages); } /* @@ -2587,7 +2592,7 @@ static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid) goto opps1; slabp->nodeid = nodeid; - set_slab_attr(cachep, slabp, objp); + slab_map_pages(cachep, slabp, objp); cache_init_objs(cachep, slabp, ctor_flags); -- cgit v1.2.3-70-g09d2 From e1b6aa6f1404f162697650df2cdb6c374b1d6a5b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 23 Jun 2006 02:03:17 -0700 Subject: [PATCH] slab: clean up kmem_getpages The last ifdef addition hit the ugliness treshold on this functions, so: - rename the variable i to nr_pages so it's somewhat descriptive - remove the addr variable and do the page_address call at the very end - instead of ifdef'ing the whole alloc_pages_node call just make the __GFP_COMP addition to flags conditional - rewrite the __GFP_COMP comment to make sense Signed-off-by: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab.c | 30 ++++++++++++++---------------- 1 file changed, 14 insertions(+), 16 deletions(-) (limited to 'mm/slab.c') diff --git a/mm/slab.c b/mm/slab.c index a94cf0fea8a..7bd19639efd 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -1489,31 +1489,29 @@ __initcall(cpucache_init); static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid) { struct page *page; - void *addr; + int nr_pages; int i; - flags |= cachep->gfpflags; #ifndef CONFIG_MMU - /* nommu uses slab's for process anonymous memory allocations, so - * requires __GFP_COMP to properly refcount higher order allocations" + /* + * Nommu uses slab's for process anonymous memory allocations, and thus + * requires __GFP_COMP to properly refcount higher order allocations */ - page = alloc_pages_node(nodeid, (flags | __GFP_COMP), cachep->gfporder); -#else - page = alloc_pages_node(nodeid, flags, cachep->gfporder); + flags |= __GFP_COMP; #endif + flags |= cachep->gfpflags; + + page = alloc_pages_node(nodeid, flags, cachep->gfporder); if (!page) return NULL; - addr = page_address(page); - i = (1 << cachep->gfporder); + nr_pages = (1 << cachep->gfporder); if (cachep->flags & SLAB_RECLAIM_ACCOUNT) - atomic_add(i, &slab_reclaim_pages); - add_page_state(nr_slab, i); - while (i--) { - __SetPageSlab(page); - page++; - } - return addr; + atomic_add(nr_pages, &slab_reclaim_pages); + add_page_state(nr_slab, nr_pages); + for (i = 0; i < nr_pages; i++) + __SetPageSlab(page + i); + return page_address(page); } /* -- cgit v1.2.3-70-g09d2 From 7a7c381d25067b9a2bfe025dfcb16459daec0373 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 23 Jun 2006 02:03:17 -0700 Subject: [PATCH] slab: stop using list_for_each Use the _entry variant everywhere to clean the code up a tiny bit. Signed-off-by: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab.c | 38 +++++++++++--------------------------- 1 file changed, 11 insertions(+), 27 deletions(-) (limited to 'mm/slab.c') diff --git a/mm/slab.c b/mm/slab.c index 7bd19639efd..54bd2eb3f2f 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -1950,8 +1950,7 @@ kmem_cache_create (const char *name, size_t size, size_t align, void (*dtor)(void*, struct kmem_cache *, unsigned long)) { size_t left_over, slab_size, ralign; - struct kmem_cache *cachep = NULL; - struct list_head *p; + struct kmem_cache *cachep = NULL, *pc; /* * Sanity checks... these are all serious usage bugs. @@ -1971,8 +1970,7 @@ kmem_cache_create (const char *name, size_t size, size_t align, mutex_lock(&cache_chain_mutex); - list_for_each(p, &cache_chain) { - struct kmem_cache *pc = list_entry(p, struct kmem_cache, next); + list_for_each_entry(pc, &cache_chain, next) { mm_segment_t old_fs = get_fs(); char tmp; int res; @@ -3690,7 +3688,7 @@ void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3, */ static void cache_reap(void *unused) { - struct list_head *walk; + struct kmem_cache *searchp; struct kmem_list3 *l3; int node = numa_node_id(); @@ -3701,13 +3699,11 @@ static void cache_reap(void *unused) return; } - list_for_each(walk, &cache_chain) { - struct kmem_cache *searchp; + list_for_each_entry(searchp, &cache_chain, next) { struct list_head *p; int tofree; struct slab *slabp; - searchp = list_entry(walk, struct kmem_cache, next); check_irq_on(); /* @@ -3835,7 +3831,6 @@ static void s_stop(struct seq_file *m, void *p) static int s_show(struct seq_file *m, void *p) { struct kmem_cache *cachep = p; - struct list_head *q; struct slab *slabp; unsigned long active_objs; unsigned long num_objs; @@ -3856,15 +3851,13 @@ static int s_show(struct seq_file *m, void *p) check_irq_on(); spin_lock_irq(&l3->list_lock); - list_for_each(q, &l3->slabs_full) { - slabp = list_entry(q, struct slab, list); + list_for_each_entry(slabp, &l3->slabs_full, list) { if (slabp->inuse != cachep->num && !error) error = "slabs_full accounting error"; active_objs += cachep->num; active_slabs++; } - list_for_each(q, &l3->slabs_partial) { - slabp = list_entry(q, struct slab, list); + list_for_each_entry(slabp, &l3->slabs_partial, list) { if (slabp->inuse == cachep->num && !error) error = "slabs_partial inuse accounting error"; if (!slabp->inuse && !error) @@ -3872,8 +3865,7 @@ static int s_show(struct seq_file *m, void *p) active_objs += slabp->inuse; active_slabs++; } - list_for_each(q, &l3->slabs_free) { - slabp = list_entry(q, struct slab, list); + list_for_each_entry(slabp, &l3->slabs_free, list) { if (slabp->inuse && !error) error = "slabs_free/inuse accounting error"; num_slabs++; @@ -3966,7 +3958,7 @@ ssize_t slabinfo_write(struct file *file, const char __user * buffer, { char kbuf[MAX_SLABINFO_WRITE + 1], *tmp; int limit, batchcount, shared, res; - struct list_head *p; + struct kmem_cache *cachep; if (count > MAX_SLABINFO_WRITE) return -EINVAL; @@ -3985,10 +3977,7 @@ ssize_t slabinfo_write(struct file *file, const char __user * buffer, /* Find the cache in the chain of caches. */ mutex_lock(&cache_chain_mutex); res = -EINVAL; - list_for_each(p, &cache_chain) { - struct kmem_cache *cachep; - - cachep = list_entry(p, struct kmem_cache, next); + list_for_each_entry(cachep, &cache_chain, next) { if (!strcmp(cachep->name, kbuf)) { if (limit < 1 || batchcount < 1 || batchcount > limit || shared < 0) { @@ -4090,7 +4079,6 @@ static void show_symbol(struct seq_file *m, unsigned long address) static int leaks_show(struct seq_file *m, void *p) { struct kmem_cache *cachep = p; - struct list_head *q; struct slab *slabp; struct kmem_list3 *l3; const char *name; @@ -4115,14 +4103,10 @@ static int leaks_show(struct seq_file *m, void *p) check_irq_on(); spin_lock_irq(&l3->list_lock); - list_for_each(q, &l3->slabs_full) { - slabp = list_entry(q, struct slab, list); + list_for_each_entry(slabp, &l3->slabs_full, list) handle_slab(n, cachep, slabp); - } - list_for_each(q, &l3->slabs_partial) { - slabp = list_entry(q, struct slab, list); + list_for_each_entry(slabp, &l3->slabs_partial, list) handle_slab(n, cachep, slabp); - } spin_unlock_irq(&l3->list_lock); } name = cachep->name; -- cgit v1.2.3-70-g09d2 From 58ce1fd5805647a58a050bbbbd2252ea5ecb47b3 Mon Sep 17 00:00:00 2001 From: Pekka Enberg Date: Fri, 23 Jun 2006 02:03:24 -0700 Subject: [PATCH] slab: redzone double-free detection At present our slab debugging tells us that it detected a double-free or corruption - it does not distinguish between them. Sometimes it's useful to be able to differentiate between these two types of information. Add double-free detection to redzone verification when freeing an object. As explained by Manfred, when we are freeing an object, both redzones should be RED_ACTIVE. However, if both are RED_INACTIVE, we are trying to free an object that was already free'd. Signed-off-by: Manfred Spraul Signed-off-by: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab.c | 32 +++++++++++++++++++++++--------- 1 file changed, 23 insertions(+), 9 deletions(-) (limited to 'mm/slab.c') diff --git a/mm/slab.c b/mm/slab.c index 54bd2eb3f2f..2046da2aa46 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2636,6 +2636,28 @@ static void kfree_debugcheck(const void *objp) } } +static inline void verify_redzone_free(struct kmem_cache *cache, void *obj) +{ + unsigned long redzone1, redzone2; + + redzone1 = *dbg_redzone1(cache, obj); + redzone2 = *dbg_redzone2(cache, obj); + + /* + * Redzone is ok. + */ + if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE) + return; + + if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE) + slab_error(cache, "double free detected"); + else + slab_error(cache, "memory outside object was overwritten"); + + printk(KERN_ERR "%p: redzone 1:0x%lx, redzone 2:0x%lx.\n", + obj, redzone1, redzone2); +} + static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, void *caller) { @@ -2659,15 +2681,7 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, slabp = page_get_slab(page); if (cachep->flags & SLAB_RED_ZONE) { - if (*dbg_redzone1(cachep, objp) != RED_ACTIVE || - *dbg_redzone2(cachep, objp) != RED_ACTIVE) { - slab_error(cachep, "double free, or memory outside" - " object was overwritten"); - printk(KERN_ERR "%p: redzone 1:0x%lx, " - "redzone 2:0x%lx.\n", - objp, *dbg_redzone1(cachep, objp), - *dbg_redzone2(cachep, objp)); - } + verify_redzone_free(cachep, objp); *dbg_redzone1(cachep, objp) = RED_INACTIVE; *dbg_redzone2(cachep, objp) = RED_INACTIVE; } -- cgit v1.2.3-70-g09d2 From ddc2e812d592457747c4367fb73edcaa8e1e49ff Mon Sep 17 00:00:00 2001 From: Pekka Enberg Date: Fri, 23 Jun 2006 02:03:40 -0700 Subject: [PATCH] slab: verify pointers before free Passing an invalid pointer to kfree() and kmem_cache_free() is likely to cause bad memory corruption or even take down the whole system because the bad pointer is likely reused immediately due to the per-CPU caches. Until now, we don't do any verification for this if CONFIG_DEBUG_SLAB is disabled. As suggested by Linus, add PageSlab check to page_to_cache() and page_to_slab() to verify pointers passed to kfree(). Also, move the stronger check from cache_free_debugcheck() to kmem_cache_free() to ensure the passed pointer actually belongs to the cache we're about to free the object. For page_to_cache() and page_to_slab(), the assertions should have virtually no extra cost (two instructions, no data cache pressure) and for kmem_cache_free() the overhead should be minimal. Signed-off-by: Pekka Enberg Cc: Manfred Spraul Cc: Christoph Lameter Cc: Linus Torvalds Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) (limited to 'mm/slab.c') diff --git a/mm/slab.c b/mm/slab.c index 2046da2aa46..e3260db04b9 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -592,6 +592,7 @@ static inline struct kmem_cache *page_get_cache(struct page *page) { if (unlikely(PageCompound(page))) page = (struct page *)page_private(page); + BUG_ON(!PageSlab(page)); return (struct kmem_cache *)page->lru.next; } @@ -604,6 +605,7 @@ static inline struct slab *page_get_slab(struct page *page) { if (unlikely(PageCompound(page))) page = (struct page *)page_private(page); + BUG_ON(!PageSlab(page)); return (struct slab *)page->lru.prev; } @@ -2669,15 +2671,6 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, kfree_debugcheck(objp); page = virt_to_page(objp); - if (page_get_cache(page) != cachep) { - printk(KERN_ERR "mismatch in kmem_cache_free: expected " - "cache %p, got %p\n", - page_get_cache(page), cachep); - printk(KERN_ERR "%p is %s.\n", cachep, cachep->name); - printk(KERN_ERR "%p is %s.\n", page_get_cache(page), - page_get_cache(page)->name); - WARN_ON(1); - } slabp = page_get_slab(page); if (cachep->flags & SLAB_RED_ZONE) { @@ -3393,6 +3386,8 @@ void kmem_cache_free(struct kmem_cache *cachep, void *objp) { unsigned long flags; + BUG_ON(virt_to_cache(objp) != cachep); + local_irq_save(flags); __cache_free(cachep, objp); local_irq_restore(flags); -- cgit v1.2.3-70-g09d2 From e0a42726794f71336ff4b26084d453dd597471ce Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 23 Jun 2006 02:03:46 -0700 Subject: [PATCH] mm/slab.c: fix early init assumption The SLAB bootstrap code assumes that the first two kmalloc caches created (the INDEX_AC and INDEX_L3 kmalloc caches) wont be off-slab. But due to AC and L3 structure size increase in lockdep, one of them ended up being off-slab, and subsequently crashing with: Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP: [] kmem_cache_alloc+0x26/0x7d The fix is to introduce a bootstrap flag and to use it to prevent off-slab caches being created so early during bootup. (The calculation for off-slab caches is quite complex so i didnt want to complicate things with introducing yet another INDEX_ calculation, the flag approach is simpler and smaller.) Signed-off-by: Ingo Molnar Cc: Manfred Spraul Cc: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'mm/slab.c') diff --git a/mm/slab.c b/mm/slab.c index e3260db04b9..664c3a10acf 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -331,6 +331,8 @@ static __always_inline int index_of(const size_t size) return 0; } +static int slab_early_init = 1; + #define INDEX_AC index_of(sizeof(struct arraycache_init)) #define INDEX_L3 index_of(sizeof(struct kmem_list3)) @@ -1376,6 +1378,8 @@ void __init kmem_cache_init(void) NULL, NULL); } + slab_early_init = 0; + while (sizes->cs_size != ULONG_MAX) { /* * For performance, all the general caches are L1 aligned. @@ -2106,8 +2110,12 @@ kmem_cache_create (const char *name, size_t size, size_t align, #endif #endif - /* Determine if the slab management is 'on' or 'off' slab. */ - if (size >= (PAGE_SIZE >> 3)) + /* + * Determine if the slab management is 'on' or 'off' slab. + * (bootstrapping cannot cope with offslab caches so don't do + * it too early on.) + */ + if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init) /* * Size is large, assume best to place the slab management obj * off-slab (should allow better packing of objs). -- cgit v1.2.3-70-g09d2 From 800590f523bf3bde9fa6c8e4d6763e4bf6a2c8ec Mon Sep 17 00:00:00 2001 From: Paul Drynoff Date: Fri, 23 Jun 2006 02:03:48 -0700 Subject: [PATCH] slab: kmalloc, kzalloc comments cleanup and fix - Move comments for kmalloc to right place, currently it near __do_kmalloc - Comments for kzalloc - More detailed comments for kmalloc - Appearance of "kmalloc" and "kzalloc" man pages after "make mandocs" [rdunlap@xenotime.net: simplification] Signed-off-by: Paul Drynoff Acked-by: Randy Dunlap Cc: Pekka Enberg Cc: Manfred Spraul Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/DocBook/kernel-api.tmpl | 1 + include/linux/slab.h | 50 +++++++++++++++++++++++++++++++++++ mm/slab.c | 20 ++------------ 3 files changed, 53 insertions(+), 18 deletions(-) (limited to 'mm/slab.c') diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl index ca02e04a906..6dab3dd3699 100644 --- a/Documentation/DocBook/kernel-api.tmpl +++ b/Documentation/DocBook/kernel-api.tmpl @@ -117,6 +117,7 @@ X!Ilib/string.c Memory Management in Linux The Slab Cache +!Iinclude/linux/slab.h !Emm/slab.c User Space Memory Access diff --git a/include/linux/slab.h b/include/linux/slab.h index 9dc93163e06..45ad55b70d1 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -86,6 +86,51 @@ extern void *__kmalloc_track_caller(size_t, gfp_t, void*); __kmalloc_track_caller(size, flags, __builtin_return_address(0)) #endif +/** + * kmalloc - allocate memory + * @size: how many bytes of memory are required. + * @flags: the type of memory to allocate. + * + * kmalloc is the normal method of allocating memory + * in the kernel. + * + * The @flags argument may be one of: + * + * %GFP_USER - Allocate memory on behalf of user. May sleep. + * + * %GFP_KERNEL - Allocate normal kernel ram. May sleep. + * + * %GFP_ATOMIC - Allocation will not sleep. + * For example, use this inside interrupt handlers. + * + * %GFP_HIGHUSER - Allocate pages from high memory. + * + * %GFP_NOIO - Do not do any I/O at all while trying to get memory. + * + * %GFP_NOFS - Do not make any fs calls while trying to get memory. + * + * Also it is possible to set different flags by OR'ing + * in one or more of the following additional @flags: + * + * %__GFP_COLD - Request cache-cold pages instead of + * trying to return cache-warm pages. + * + * %__GFP_DMA - Request memory from the DMA-capable zone. + * + * %__GFP_HIGH - This allocation has high priority and may use emergency pools. + * + * %__GFP_HIGHMEM - Allocated memory may be from highmem. + * + * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail + * (think twice before using). + * + * %__GFP_NORETRY - If memory is not immediately available, + * then give up at once. + * + * %__GFP_NOWARN - If allocation fails, don't issue any warnings. + * + * %__GFP_REPEAT - If allocation fails initially, try once more before failing. + */ static inline void *kmalloc(size_t size, gfp_t flags) { if (__builtin_constant_p(size)) { @@ -111,6 +156,11 @@ found: extern void *__kzalloc(size_t, gfp_t); +/** + * kzalloc - allocate memory. The memory is set to zero. + * @size: how many bytes of memory are required. + * @flags: the type of memory to allocate (see kmalloc). + */ static inline void *kzalloc(size_t size, gfp_t flags) { if (__builtin_constant_p(size)) { diff --git a/mm/slab.c b/mm/slab.c index 664c3a10acf..98ac20bc0de 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -3277,26 +3277,10 @@ EXPORT_SYMBOL(kmalloc_node); #endif /** - * kmalloc - allocate memory + * __do_kmalloc - allocate memory * @size: how many bytes of memory are required. - * @flags: the type of memory to allocate. + * @flags: the type of memory to allocate (see kmalloc). * @caller: function caller for debug tracking of the caller - * - * kmalloc is the normal method of allocating memory - * in the kernel. - * - * The @flags argument may be one of: - * - * %GFP_USER - Allocate memory on behalf of user. May sleep. - * - * %GFP_KERNEL - Allocate normal kernel ram. May sleep. - * - * %GFP_ATOMIC - Allocation will not sleep. Use inside interrupt handlers. - * - * Additionally, the %GFP_DMA flag may be set to indicate the memory - * must be suitable for DMA. This can mean different things on different - * platforms. For example, on i386, it means that the memory must come - * from the first 16MB. */ static __always_inline void *__do_kmalloc(size_t size, gfp_t flags, void *caller) -- cgit v1.2.3-70-g09d2