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-rw-r--r--mm/slab.c286
1 files changed, 195 insertions, 91 deletions
diff --git a/mm/slab.c b/mm/slab.c
index 5de81473df3..068cb4503c1 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -103,12 +103,12 @@
#include <linux/module.h>
#include <linux/rcupdate.h>
#include <linux/string.h>
+#include <linux/uaccess.h>
#include <linux/nodemask.h>
#include <linux/mempolicy.h>
#include <linux/mutex.h>
#include <linux/rtmutex.h>
-#include <asm/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/page.h>
@@ -730,7 +730,10 @@ static inline void init_lock_keys(void)
}
#endif
-/* Guard access to the cache-chain. */
+/*
+ * 1. Guard access to the cache-chain.
+ * 2. Protect sanity of cpu_online_map against cpu hotplug events
+ */
static DEFINE_MUTEX(cache_chain_mutex);
static struct list_head cache_chain;
@@ -866,6 +869,22 @@ static void __slab_error(const char *function, struct kmem_cache *cachep,
dump_stack();
}
+/*
+ * By default on NUMA we use alien caches to stage the freeing of
+ * objects allocated from other nodes. This causes massive memory
+ * inefficiencies when using fake NUMA setup to split memory into a
+ * large number of small nodes, so it can be disabled on the command
+ * line
+ */
+
+static int use_alien_caches __read_mostly = 1;
+static int __init noaliencache_setup(char *s)
+{
+ use_alien_caches = 0;
+ return 1;
+}
+__setup("noaliencache", noaliencache_setup);
+
#ifdef CONFIG_NUMA
/*
* Special reaping functions for NUMA systems called from cache_reap().
@@ -996,7 +1015,7 @@ static inline void *alternate_node_alloc(struct kmem_cache *cachep,
return NULL;
}
-static inline void *__cache_alloc_node(struct kmem_cache *cachep,
+static inline void *____cache_alloc_node(struct kmem_cache *cachep,
gfp_t flags, int nodeid)
{
return NULL;
@@ -1004,7 +1023,7 @@ static inline void *__cache_alloc_node(struct kmem_cache *cachep,
#else /* CONFIG_NUMA */
-static void *__cache_alloc_node(struct kmem_cache *, gfp_t, int);
+static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
static struct array_cache **alloc_alien_cache(int node, int limit)
@@ -1114,7 +1133,7 @@ static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
* Make sure we are not freeing a object from another node to the array
* cache on this cpu.
*/
- if (likely(slabp->nodeid == node))
+ if (likely(slabp->nodeid == node) || unlikely(!use_alien_caches))
return 0;
l3 = cachep->nodelists[node];
@@ -1192,7 +1211,7 @@ static int __cpuinit cpuup_callback(struct notifier_block *nfb,
list_for_each_entry(cachep, &cache_chain, next) {
struct array_cache *nc;
struct array_cache *shared;
- struct array_cache **alien;
+ struct array_cache **alien = NULL;
nc = alloc_arraycache(node, cachep->limit,
cachep->batchcount);
@@ -1204,9 +1223,11 @@ static int __cpuinit cpuup_callback(struct notifier_block *nfb,
if (!shared)
goto bad;
- alien = alloc_alien_cache(node, cachep->limit);
- if (!alien)
- goto bad;
+ if (use_alien_caches) {
+ alien = alloc_alien_cache(node, cachep->limit);
+ if (!alien)
+ goto bad;
+ }
cachep->array[cpu] = nc;
l3 = cachep->nodelists[node];
BUG_ON(!l3);
@@ -1230,12 +1251,18 @@ static int __cpuinit cpuup_callback(struct notifier_block *nfb,
kfree(shared);
free_alien_cache(alien);
}
- mutex_unlock(&cache_chain_mutex);
break;
case CPU_ONLINE:
+ mutex_unlock(&cache_chain_mutex);
start_cpu_timer(cpu);
break;
#ifdef CONFIG_HOTPLUG_CPU
+ case CPU_DOWN_PREPARE:
+ mutex_lock(&cache_chain_mutex);
+ break;
+ case CPU_DOWN_FAILED:
+ mutex_unlock(&cache_chain_mutex);
+ break;
case CPU_DEAD:
/*
* Even if all the cpus of a node are down, we don't free the
@@ -1246,8 +1273,8 @@ static int __cpuinit cpuup_callback(struct notifier_block *nfb,
* gets destroyed at kmem_cache_destroy().
*/
/* fall thru */
+#endif
case CPU_UP_CANCELED:
- mutex_lock(&cache_chain_mutex);
list_for_each_entry(cachep, &cache_chain, next) {
struct array_cache *nc;
struct array_cache *shared;
@@ -1308,11 +1335,9 @@ free_array_cache:
}
mutex_unlock(&cache_chain_mutex);
break;
-#endif
}
return NOTIFY_OK;
bad:
- mutex_unlock(&cache_chain_mutex);
return NOTIFY_BAD;
}
@@ -1580,12 +1605,7 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
flags |= __GFP_COMP;
#endif
- /*
- * Under NUMA we want memory on the indicated node. We will handle
- * the needed fallback ourselves since we want to serve from our
- * per node object lists first for other nodes.
- */
- flags |= cachep->gfpflags | GFP_THISNODE;
+ flags |= cachep->gfpflags;
page = alloc_pages_node(nodeid, flags, cachep->gfporder);
if (!page)
@@ -2098,15 +2118,12 @@ kmem_cache_create (const char *name, size_t size, size_t align,
}
/*
- * Prevent CPUs from coming and going.
- * lock_cpu_hotplug() nests outside cache_chain_mutex
+ * We use cache_chain_mutex to ensure a consistent view of
+ * cpu_online_map as well. Please see cpuup_callback
*/
- lock_cpu_hotplug();
-
mutex_lock(&cache_chain_mutex);
list_for_each_entry(pc, &cache_chain, next) {
- mm_segment_t old_fs = get_fs();
char tmp;
int res;
@@ -2115,9 +2132,7 @@ kmem_cache_create (const char *name, size_t size, size_t align,
* destroy its slab cache and no-one else reuses the vmalloc
* area of the module. Print a warning.
*/
- set_fs(KERNEL_DS);
- res = __get_user(tmp, pc->name);
- set_fs(old_fs);
+ res = probe_kernel_address(pc->name, tmp);
if (res) {
printk("SLAB: cache with size %d has lost its name\n",
pc->buffer_size);
@@ -2197,25 +2212,24 @@ kmem_cache_create (const char *name, size_t size, size_t align,
if (flags & SLAB_RED_ZONE || flags & SLAB_STORE_USER)
ralign = BYTES_PER_WORD;
- /* 2) arch mandated alignment: disables debug if necessary */
+ /* 2) arch mandated alignment */
if (ralign < ARCH_SLAB_MINALIGN) {
ralign = ARCH_SLAB_MINALIGN;
- if (ralign > BYTES_PER_WORD)
- flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
}
- /* 3) caller mandated alignment: disables debug if necessary */
+ /* 3) caller mandated alignment */
if (ralign < align) {
ralign = align;
- if (ralign > BYTES_PER_WORD)
- flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
}
+ /* disable debug if necessary */
+ if (ralign > BYTES_PER_WORD)
+ flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
/*
* 4) Store it.
*/
align = ralign;
/* Get cache's description obj. */
- cachep = kmem_cache_zalloc(&cache_cache, SLAB_KERNEL);
+ cachep = kmem_cache_zalloc(&cache_cache, GFP_KERNEL);
if (!cachep)
goto oops;
@@ -2326,7 +2340,6 @@ oops:
panic("kmem_cache_create(): failed to create slab `%s'\n",
name);
mutex_unlock(&cache_chain_mutex);
- unlock_cpu_hotplug();
return cachep;
}
EXPORT_SYMBOL(kmem_cache_create);
@@ -2444,6 +2457,7 @@ out:
return nr_freed;
}
+/* Called with cache_chain_mutex held to protect against cpu hotplug */
static int __cache_shrink(struct kmem_cache *cachep)
{
int ret = 0, i = 0;
@@ -2474,9 +2488,13 @@ static int __cache_shrink(struct kmem_cache *cachep)
*/
int kmem_cache_shrink(struct kmem_cache *cachep)
{
+ int ret;
BUG_ON(!cachep || in_interrupt());
- return __cache_shrink(cachep);
+ mutex_lock(&cache_chain_mutex);
+ ret = __cache_shrink(cachep);
+ mutex_unlock(&cache_chain_mutex);
+ return ret;
}
EXPORT_SYMBOL(kmem_cache_shrink);
@@ -2500,23 +2518,16 @@ void kmem_cache_destroy(struct kmem_cache *cachep)
{
BUG_ON(!cachep || in_interrupt());
- /* Don't let CPUs to come and go */
- lock_cpu_hotplug();
-
/* Find the cache in the chain of caches. */
mutex_lock(&cache_chain_mutex);
/*
* the chain is never empty, cache_cache is never destroyed
*/
list_del(&cachep->next);
- mutex_unlock(&cache_chain_mutex);
-
if (__cache_shrink(cachep)) {
slab_error(cachep, "Can't free all objects");
- mutex_lock(&cache_chain_mutex);
list_add(&cachep->next, &cache_chain);
mutex_unlock(&cache_chain_mutex);
- unlock_cpu_hotplug();
return;
}
@@ -2524,7 +2535,7 @@ void kmem_cache_destroy(struct kmem_cache *cachep)
synchronize_rcu();
__kmem_cache_destroy(cachep);
- unlock_cpu_hotplug();
+ mutex_unlock(&cache_chain_mutex);
}
EXPORT_SYMBOL(kmem_cache_destroy);
@@ -2548,7 +2559,7 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
if (OFF_SLAB(cachep)) {
/* Slab management obj is off-slab. */
slabp = kmem_cache_alloc_node(cachep->slabp_cache,
- local_flags, nodeid);
+ local_flags & ~GFP_THISNODE, nodeid);
if (!slabp)
return NULL;
} else {
@@ -2618,7 +2629,7 @@ static void cache_init_objs(struct kmem_cache *cachep,
static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
{
- if (flags & SLAB_DMA)
+ if (flags & GFP_DMA)
BUG_ON(!(cachep->gfpflags & GFP_DMA));
else
BUG_ON(cachep->gfpflags & GFP_DMA);
@@ -2689,10 +2700,10 @@ static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
* Grow (by 1) the number of slabs within a cache. This is called by
* kmem_cache_alloc() when there are no active objs left in a cache.
*/
-static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid)
+static int cache_grow(struct kmem_cache *cachep,
+ gfp_t flags, int nodeid, void *objp)
{
struct slab *slabp;
- void *objp;
size_t offset;
gfp_t local_flags;
unsigned long ctor_flags;
@@ -2702,12 +2713,12 @@ static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid)
* Be lazy and only check for valid flags here, keeping it out of the
* critical path in kmem_cache_alloc().
*/
- BUG_ON(flags & ~(SLAB_DMA | SLAB_LEVEL_MASK | SLAB_NO_GROW));
- if (flags & SLAB_NO_GROW)
+ BUG_ON(flags & ~(GFP_DMA | GFP_LEVEL_MASK | __GFP_NO_GROW));
+ if (flags & __GFP_NO_GROW)
return 0;
ctor_flags = SLAB_CTOR_CONSTRUCTOR;
- local_flags = (flags & SLAB_LEVEL_MASK);
+ local_flags = (flags & GFP_LEVEL_MASK);
if (!(local_flags & __GFP_WAIT))
/*
* Not allowed to sleep. Need to tell a constructor about
@@ -2744,12 +2755,14 @@ static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid)
* Get mem for the objs. Attempt to allocate a physical page from
* 'nodeid'.
*/
- objp = kmem_getpages(cachep, flags, nodeid);
+ if (!objp)
+ objp = kmem_getpages(cachep, flags, nodeid);
if (!objp)
goto failed;
/* Get slab management. */
- slabp = alloc_slabmgmt(cachep, objp, offset, local_flags, nodeid);
+ slabp = alloc_slabmgmt(cachep, objp, offset,
+ local_flags & ~GFP_THISNODE, nodeid);
if (!slabp)
goto opps1;
@@ -2987,7 +3000,7 @@ alloc_done:
if (unlikely(!ac->avail)) {
int x;
- x = cache_grow(cachep, flags, node);
+ x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL);
/* cache_grow can reenable interrupts, then ac could change. */
ac = cpu_cache_get(cachep);
@@ -3063,6 +3076,12 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
cachep->ctor(objp, cachep, ctor_flags);
}
+#if ARCH_SLAB_MINALIGN
+ if ((u32)objp & (ARCH_SLAB_MINALIGN-1)) {
+ printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",
+ objp, ARCH_SLAB_MINALIGN);
+ }
+#endif
return objp;
}
#else
@@ -3105,10 +3124,10 @@ static __always_inline void *__cache_alloc(struct kmem_cache *cachep,
objp = ____cache_alloc(cachep, flags);
/*
* We may just have run out of memory on the local node.
- * __cache_alloc_node() knows how to locate memory on other nodes
+ * ____cache_alloc_node() knows how to locate memory on other nodes
*/
if (NUMA_BUILD && !objp)
- objp = __cache_alloc_node(cachep, flags, numa_node_id());
+ objp = ____cache_alloc_node(cachep, flags, numa_node_id());
local_irq_restore(save_flags);
objp = cache_alloc_debugcheck_after(cachep, flags, objp,
caller);
@@ -3135,15 +3154,17 @@ static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
else if (current->mempolicy)
nid_alloc = slab_node(current->mempolicy);
if (nid_alloc != nid_here)
- return __cache_alloc_node(cachep, flags, nid_alloc);
+ return ____cache_alloc_node(cachep, flags, nid_alloc);
return NULL;
}
/*
* Fallback function if there was no memory available and no objects on a
- * certain node and we are allowed to fall back. We mimick the behavior of
- * the page allocator. We fall back according to a zonelist determined by
- * the policy layer while obeying cpuset constraints.
+ * certain node and fall back is permitted. First we scan all the
+ * available nodelists for available objects. If that fails then we
+ * perform an allocation without specifying a node. This allows the page
+ * allocator to do its reclaim / fallback magic. We then insert the
+ * slab into the proper nodelist and then allocate from it.
*/
void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
{
@@ -3151,15 +3172,51 @@ void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
->node_zonelists[gfp_zone(flags)];
struct zone **z;
void *obj = NULL;
+ int nid;
+retry:
+ /*
+ * Look through allowed nodes for objects available
+ * from existing per node queues.
+ */
for (z = zonelist->zones; *z && !obj; z++) {
- int nid = zone_to_nid(*z);
+ nid = zone_to_nid(*z);
+
+ if (cpuset_zone_allowed(*z, flags) &&
+ cache->nodelists[nid] &&
+ cache->nodelists[nid]->free_objects)
+ obj = ____cache_alloc_node(cache,
+ flags | GFP_THISNODE, nid);
+ }
- if (zone_idx(*z) <= ZONE_NORMAL &&
- cpuset_zone_allowed(*z, flags) &&
- cache->nodelists[nid])
- obj = __cache_alloc_node(cache,
- flags | __GFP_THISNODE, nid);
+ if (!obj) {
+ /*
+ * This allocation will be performed within the constraints
+ * of the current cpuset / memory policy requirements.
+ * We may trigger various forms of reclaim on the allowed
+ * set and go into memory reserves if necessary.
+ */
+ obj = kmem_getpages(cache, flags, -1);
+ if (obj) {
+ /*
+ * Insert into the appropriate per node queues
+ */
+ nid = page_to_nid(virt_to_page(obj));
+ if (cache_grow(cache, flags, nid, obj)) {
+ obj = ____cache_alloc_node(cache,
+ flags | GFP_THISNODE, nid);
+ if (!obj)
+ /*
+ * Another processor may allocate the
+ * objects in the slab since we are
+ * not holding any locks.
+ */
+ goto retry;
+ } else {
+ kmem_freepages(cache, obj);
+ obj = NULL;
+ }
+ }
}
return obj;
}
@@ -3167,7 +3224,7 @@ void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
/*
* A interface to enable slab creation on nodeid
*/
-static void *__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
+static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
int nodeid)
{
struct list_head *entry;
@@ -3216,7 +3273,7 @@ retry:
must_grow:
spin_unlock(&l3->list_lock);
- x = cache_grow(cachep, flags, nodeid);
+ x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL);
if (x)
goto retry;
@@ -3434,35 +3491,59 @@ out:
* @flags: See kmalloc().
* @nodeid: node number of the target node.
*
- * Identical to kmem_cache_alloc, except that this function is slow
- * and can sleep. And it will allocate memory on the given node, which
- * can improve the performance for cpu bound structures.
- * New and improved: it will now make sure that the object gets
- * put on the correct node list so that there is no false sharing.
+ * Identical to kmem_cache_alloc but it will allocate memory on the given
+ * node, which can improve the performance for cpu bound structures.
+ *
+ * Fallback to other node is possible if __GFP_THISNODE is not set.
*/
-void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
+static __always_inline void *
+__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
+ int nodeid, void *caller)
{
unsigned long save_flags;
- void *ptr;
+ void *ptr = NULL;
cache_alloc_debugcheck_before(cachep, flags);
local_irq_save(save_flags);
- if (nodeid == -1 || nodeid == numa_node_id() ||
- !cachep->nodelists[nodeid])
- ptr = ____cache_alloc(cachep, flags);
- else
- ptr = __cache_alloc_node(cachep, flags, nodeid);
- local_irq_restore(save_flags);
+ if (unlikely(nodeid == -1))
+ nodeid = numa_node_id();
+
+ if (likely(cachep->nodelists[nodeid])) {
+ if (nodeid == numa_node_id()) {
+ /*
+ * Use the locally cached objects if possible.
+ * However ____cache_alloc does not allow fallback
+ * to other nodes. It may fail while we still have
+ * objects on other nodes available.
+ */
+ ptr = ____cache_alloc(cachep, flags);
+ }
+ if (!ptr) {
+ /* ___cache_alloc_node can fall back to other nodes */
+ ptr = ____cache_alloc_node(cachep, flags, nodeid);
+ }
+ } else {
+ /* Node not bootstrapped yet */
+ if (!(flags & __GFP_THISNODE))
+ ptr = fallback_alloc(cachep, flags);
+ }
- ptr = cache_alloc_debugcheck_after(cachep, flags, ptr,
- __builtin_return_address(0));
+ local_irq_restore(save_flags);
+ ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller);
return ptr;
}
+
+void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
+{
+ return __cache_alloc_node(cachep, flags, nodeid,
+ __builtin_return_address(0));
+}
EXPORT_SYMBOL(kmem_cache_alloc_node);
-void *__kmalloc_node(size_t size, gfp_t flags, int node)
+static __always_inline void *
+__do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller)
{
struct kmem_cache *cachep;
@@ -3471,8 +3552,29 @@ void *__kmalloc_node(size_t size, gfp_t flags, int node)
return NULL;
return kmem_cache_alloc_node(cachep, flags, node);
}
+
+#ifdef CONFIG_DEBUG_SLAB
+void *__kmalloc_node(size_t size, gfp_t flags, int node)
+{
+ return __do_kmalloc_node(size, flags, node,
+ __builtin_return_address(0));
+}
EXPORT_SYMBOL(__kmalloc_node);
-#endif
+
+void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
+ int node, void *caller)
+{
+ return __do_kmalloc_node(size, flags, node, caller);
+}
+EXPORT_SYMBOL(__kmalloc_node_track_caller);
+#else
+void *__kmalloc_node(size_t size, gfp_t flags, int node)
+{
+ return __do_kmalloc_node(size, flags, node, NULL);
+}
+EXPORT_SYMBOL(__kmalloc_node);
+#endif /* CONFIG_DEBUG_SLAB */
+#endif /* CONFIG_NUMA */
/**
* __do_kmalloc - allocate memory
@@ -3583,13 +3685,15 @@ static int alloc_kmemlist(struct kmem_cache *cachep)
int node;
struct kmem_list3 *l3;
struct array_cache *new_shared;
- struct array_cache **new_alien;
+ struct array_cache **new_alien = NULL;
for_each_online_node(node) {
- new_alien = alloc_alien_cache(node, cachep->limit);
- if (!new_alien)
- goto fail;
+ if (use_alien_caches) {
+ new_alien = alloc_alien_cache(node, cachep->limit);
+ if (!new_alien)
+ goto fail;
+ }
new_shared = alloc_arraycache(node,
cachep->shared*cachep->batchcount,
@@ -4038,7 +4142,7 @@ static int s_show(struct seq_file *m, void *p)
* + further values on SMP and with statistics enabled
*/
-struct seq_operations slabinfo_op = {
+const struct seq_operations slabinfo_op = {
.start = s_start,
.next = s_next,
.stop = s_stop,
@@ -4236,7 +4340,7 @@ static int leaks_show(struct seq_file *m, void *p)
return 0;
}
-struct seq_operations slabstats_op = {
+const struct seq_operations slabstats_op = {
.start = leaks_start,
.next = s_next,
.stop = s_stop,
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-01 23:03:37 +0000