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Diffstat (limited to 'mm/vmalloc.c')
-rw-r--r--mm/vmalloc.c158
1 files changed, 104 insertions, 54 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index f9b166732e70..5d6030235d7a 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -261,8 +261,15 @@ struct vmap_area {
};
static DEFINE_SPINLOCK(vmap_area_lock);
-static struct rb_root vmap_area_root = RB_ROOT;
static LIST_HEAD(vmap_area_list);
+static struct rb_root vmap_area_root = RB_ROOT;
+
+/* The vmap cache globals are protected by vmap_area_lock */
+static struct rb_node *free_vmap_cache;
+static unsigned long cached_hole_size;
+static unsigned long cached_vstart;
+static unsigned long cached_align;
+
static unsigned long vmap_area_pcpu_hole;
static struct vmap_area *__find_vmap_area(unsigned long addr)
@@ -331,9 +338,11 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
struct rb_node *n;
unsigned long addr;
int purged = 0;
+ struct vmap_area *first;
BUG_ON(!size);
BUG_ON(size & ~PAGE_MASK);
+ BUG_ON(!is_power_of_2(align));
va = kmalloc_node(sizeof(struct vmap_area),
gfp_mask & GFP_RECLAIM_MASK, node);
@@ -341,79 +350,106 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
return ERR_PTR(-ENOMEM);
retry:
- addr = ALIGN(vstart, align);
-
spin_lock(&vmap_area_lock);
- if (addr + size - 1 < addr)
- goto overflow;
+ /*
+ * Invalidate cache if we have more permissive parameters.
+ * cached_hole_size notes the largest hole noticed _below_
+ * the vmap_area cached in free_vmap_cache: if size fits
+ * into that hole, we want to scan from vstart to reuse
+ * the hole instead of allocating above free_vmap_cache.
+ * Note that __free_vmap_area may update free_vmap_cache
+ * without updating cached_hole_size or cached_align.
+ */
+ if (!free_vmap_cache ||
+ size < cached_hole_size ||
+ vstart < cached_vstart ||
+ align < cached_align) {
+nocache:
+ cached_hole_size = 0;
+ free_vmap_cache = NULL;
+ }
+ /* record if we encounter less permissive parameters */
+ cached_vstart = vstart;
+ cached_align = align;
+
+ /* find starting point for our search */
+ if (free_vmap_cache) {
+ first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
+ addr = ALIGN(first->va_end + PAGE_SIZE, align);
+ if (addr < vstart)
+ goto nocache;
+ if (addr + size - 1 < addr)
+ goto overflow;
+
+ } else {
+ addr = ALIGN(vstart, align);
+ if (addr + size - 1 < addr)
+ goto overflow;
- /* XXX: could have a last_hole cache */
- n = vmap_area_root.rb_node;
- if (n) {
- struct vmap_area *first = NULL;
+ n = vmap_area_root.rb_node;
+ first = NULL;
- do {
+ while (n) {
struct vmap_area *tmp;
tmp = rb_entry(n, struct vmap_area, rb_node);
if (tmp->va_end >= addr) {
- if (!first && tmp->va_start < addr + size)
- first = tmp;
- n = n->rb_left;
- } else {
first = tmp;
+ if (tmp->va_start <= addr)
+ break;
+ n = n->rb_left;
+ } else
n = n->rb_right;
- }
- } while (n);
+ }
if (!first)
goto found;
-
- if (first->va_end < addr) {
- n = rb_next(&first->rb_node);
- if (n)
- first = rb_entry(n, struct vmap_area, rb_node);
- else
- goto found;
- }
-
- while (addr + size > first->va_start && addr + size <= vend) {
- addr = ALIGN(first->va_end + PAGE_SIZE, align);
- if (addr + size - 1 < addr)
- goto overflow;
-
- n = rb_next(&first->rb_node);
- if (n)
- first = rb_entry(n, struct vmap_area, rb_node);
- else
- goto found;
- }
}
-found:
- if (addr + size > vend) {
-overflow:
- spin_unlock(&vmap_area_lock);
- if (!purged) {
- purge_vmap_area_lazy();
- purged = 1;
- goto retry;
- }
- if (printk_ratelimit())
- printk(KERN_WARNING
- "vmap allocation for size %lu failed: "
- "use vmalloc=<size> to increase size.\n", size);
- kfree(va);
- return ERR_PTR(-EBUSY);
+
+ /* from the starting point, walk areas until a suitable hole is found */
+ while (addr + size >= first->va_start && addr + size <= vend) {
+ if (addr + cached_hole_size < first->va_start)
+ cached_hole_size = first->va_start - addr;
+ addr = ALIGN(first->va_end + PAGE_SIZE, align);
+ if (addr + size - 1 < addr)
+ goto overflow;
+
+ n = rb_next(&first->rb_node);
+ if (n)
+ first = rb_entry(n, struct vmap_area, rb_node);
+ else
+ goto found;
}
- BUG_ON(addr & (align-1));
+found:
+ if (addr + size > vend)
+ goto overflow;
va->va_start = addr;
va->va_end = addr + size;
va->flags = 0;
__insert_vmap_area(va);
+ free_vmap_cache = &va->rb_node;
spin_unlock(&vmap_area_lock);
+ BUG_ON(va->va_start & (align-1));
+ BUG_ON(va->va_start < vstart);
+ BUG_ON(va->va_end > vend);
+
return va;
+
+overflow:
+ spin_unlock(&vmap_area_lock);
+ if (!purged) {
+ purge_vmap_area_lazy();
+ purged = 1;
+ goto retry;
+ }
+ if (printk_ratelimit())
+ printk(KERN_WARNING
+ "vmap allocation for size %lu failed: "
+ "use vmalloc=<size> to increase size.\n", size);
+ kfree(va);
+ return ERR_PTR(-EBUSY);
}
static void rcu_free_va(struct rcu_head *head)
@@ -426,6 +462,22 @@ static void rcu_free_va(struct rcu_head *head)
static void __free_vmap_area(struct vmap_area *va)
{
BUG_ON(RB_EMPTY_NODE(&va->rb_node));
+
+ if (free_vmap_cache) {
+ if (va->va_end < cached_vstart) {
+ free_vmap_cache = NULL;
+ } else {
+ struct vmap_area *cache;
+ cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
+ if (va->va_start <= cache->va_start) {
+ free_vmap_cache = rb_prev(&va->rb_node);
+ /*
+ * We don't try to update cached_hole_size or
+ * cached_align, but it won't go very wrong.
+ */
+ }
+ }
+ }
rb_erase(&va->rb_node, &vmap_area_root);
RB_CLEAR_NODE(&va->rb_node);
list_del_rcu(&va->list);
@@ -1951,8 +2003,6 @@ finished:
* should know vmalloc() area is valid and can use memcpy().
* This is for routines which have to access vmalloc area without
* any informaion, as /dev/kmem.
- *
- * The caller should guarantee KM_USER1 is not used.
*/
long vwrite(char *buf, char *addr, unsigned long count)
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-18 12:17:47 +0000