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Diffstat (limited to 'mm/vmalloc.c')
-rw-r--r--mm/vmalloc.c130
1 files changed, 90 insertions, 40 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 1d13d71687d7..93cf99aba335 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -103,7 +103,7 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
if (!pte)
return -ENOMEM;
do {
- BUG_ON(!pte_none(*pte));
+ BUG_ON(!pte_none(ptep_get(pte)));
#ifdef CONFIG_HUGETLB_PAGE
size = arch_vmap_pte_range_map_size(addr, end, pfn, max_page_shift);
@@ -472,7 +472,7 @@ static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr,
do {
struct page *page = pages[*nr];
- if (WARN_ON(!pte_none(*pte)))
+ if (WARN_ON(!pte_none(ptep_get(pte))))
return -EBUSY;
if (WARN_ON(!page))
return -ENOMEM;
@@ -703,11 +703,10 @@ struct page *vmalloc_to_page(const void *vmalloc_addr)
if (WARN_ON_ONCE(pmd_bad(*pmd)))
return NULL;
- ptep = pte_offset_map(pmd, addr);
- pte = *ptep;
+ ptep = pte_offset_kernel(pmd, addr);
+ pte = ptep_get(ptep);
if (pte_present(pte))
page = pte_page(pte);
- pte_unmap(ptep);
return page;
}
@@ -791,7 +790,7 @@ get_subtree_max_size(struct rb_node *node)
RB_DECLARE_CALLBACKS_MAX(static, free_vmap_area_rb_augment_cb,
struct vmap_area, rb_node, unsigned long, subtree_max_size, va_size)
-static void purge_vmap_area_lazy(void);
+static void reclaim_and_purge_vmap_areas(void);
static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);
static void drain_vmap_area_work(struct work_struct *work);
static DECLARE_WORK(drain_vmap_work, drain_vmap_area_work);
@@ -1649,7 +1648,7 @@ retry:
overflow:
if (!purged) {
- purge_vmap_area_lazy();
+ reclaim_and_purge_vmap_areas();
purged = 1;
goto retry;
}
@@ -1785,9 +1784,10 @@ out:
}
/*
- * Kick off a purge of the outstanding lazy areas.
+ * Reclaim vmap areas by purging fragmented blocks and purge_vmap_area_list.
*/
-static void purge_vmap_area_lazy(void)
+static void reclaim_and_purge_vmap_areas(void)
+
{
mutex_lock(&vmap_purge_lock);
purge_fragmented_blocks_allcpus();
@@ -1908,6 +1908,12 @@ static struct vmap_area *find_unlink_vmap_area(unsigned long addr)
#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
+/*
+ * Purge threshold to prevent overeager purging of fragmented blocks for
+ * regular operations: Purge if vb->free is less than 1/4 of the capacity.
+ */
+#define VMAP_PURGE_THRESHOLD (VMAP_BBMAP_BITS / 4)
+
#define VMAP_RAM 0x1 /* indicates vm_map_ram area*/
#define VMAP_BLOCK 0x2 /* mark out the vmap_block sub-type*/
#define VMAP_FLAGS_MASK 0x3
@@ -2086,39 +2092,62 @@ static void free_vmap_block(struct vmap_block *vb)
kfree_rcu(vb, rcu_head);
}
+static bool purge_fragmented_block(struct vmap_block *vb,
+ struct vmap_block_queue *vbq, struct list_head *purge_list,
+ bool force_purge)
+{
+ if (vb->free + vb->dirty != VMAP_BBMAP_BITS ||
+ vb->dirty == VMAP_BBMAP_BITS)
+ return false;
+
+ /* Don't overeagerly purge usable blocks unless requested */
+ if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD))
+ return false;
+
+ /* prevent further allocs after releasing lock */
+ WRITE_ONCE(vb->free, 0);
+ /* prevent purging it again */
+ WRITE_ONCE(vb->dirty, VMAP_BBMAP_BITS);
+ vb->dirty_min = 0;
+ vb->dirty_max = VMAP_BBMAP_BITS;
+ spin_lock(&vbq->lock);
+ list_del_rcu(&vb->free_list);
+ spin_unlock(&vbq->lock);
+ list_add_tail(&vb->purge, purge_list);
+ return true;
+}
+
+static void free_purged_blocks(struct list_head *purge_list)
+{
+ struct vmap_block *vb, *n_vb;
+
+ list_for_each_entry_safe(vb, n_vb, purge_list, purge) {
+ list_del(&vb->purge);
+ free_vmap_block(vb);
+ }
+}
+
static void purge_fragmented_blocks(int cpu)
{
LIST_HEAD(purge);
struct vmap_block *vb;
- struct vmap_block *n_vb;
struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
rcu_read_lock();
list_for_each_entry_rcu(vb, &vbq->free, free_list) {
+ unsigned long free = READ_ONCE(vb->free);
+ unsigned long dirty = READ_ONCE(vb->dirty);
- if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
+ if (free + dirty != VMAP_BBMAP_BITS ||
+ dirty == VMAP_BBMAP_BITS)
continue;
spin_lock(&vb->lock);
- if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
- vb->free = 0; /* prevent further allocs after releasing lock */
- vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
- vb->dirty_min = 0;
- vb->dirty_max = VMAP_BBMAP_BITS;
- spin_lock(&vbq->lock);
- list_del_rcu(&vb->free_list);
- spin_unlock(&vbq->lock);
- spin_unlock(&vb->lock);
- list_add_tail(&vb->purge, &purge);
- } else
- spin_unlock(&vb->lock);
+ purge_fragmented_block(vb, vbq, &purge, true);
+ spin_unlock(&vb->lock);
}
rcu_read_unlock();
-
- list_for_each_entry_safe(vb, n_vb, &purge, purge) {
- list_del(&vb->purge);
- free_vmap_block(vb);
- }
+ free_purged_blocks(&purge);
}
static void purge_fragmented_blocks_allcpus(void)
@@ -2153,6 +2182,9 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
list_for_each_entry_rcu(vb, &vbq->free, free_list) {
unsigned long pages_off;
+ if (READ_ONCE(vb->free) < (1UL << order))
+ continue;
+
spin_lock(&vb->lock);
if (vb->free < (1UL << order)) {
spin_unlock(&vb->lock);
@@ -2161,7 +2193,7 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
pages_off = VMAP_BBMAP_BITS - vb->free;
vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
- vb->free -= 1UL << order;
+ WRITE_ONCE(vb->free, vb->free - (1UL << order));
bitmap_set(vb->used_map, pages_off, (1UL << order));
if (vb->free == 0) {
spin_lock(&vbq->lock);
@@ -2211,11 +2243,11 @@ static void vb_free(unsigned long addr, unsigned long size)
spin_lock(&vb->lock);
- /* Expand dirty range */
+ /* Expand the not yet TLB flushed dirty range */
vb->dirty_min = min(vb->dirty_min, offset);
vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
- vb->dirty += 1UL << order;
+ WRITE_ONCE(vb->dirty, vb->dirty + (1UL << order));
if (vb->dirty == VMAP_BBMAP_BITS) {
BUG_ON(vb->free);
spin_unlock(&vb->lock);
@@ -2226,21 +2258,30 @@ static void vb_free(unsigned long addr, unsigned long size)
static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush)
{
+ LIST_HEAD(purge_list);
int cpu;
if (unlikely(!vmap_initialized))
return;
- might_sleep();
+ mutex_lock(&vmap_purge_lock);
for_each_possible_cpu(cpu) {
struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
struct vmap_block *vb;
+ unsigned long idx;
rcu_read_lock();
- list_for_each_entry_rcu(vb, &vbq->free, free_list) {
+ xa_for_each(&vbq->vmap_blocks, idx, vb) {
spin_lock(&vb->lock);
- if (vb->dirty && vb->dirty != VMAP_BBMAP_BITS) {
+
+ /*
+ * Try to purge a fragmented block first. If it's
+ * not purgeable, check whether there is dirty
+ * space to be flushed.
+ */
+ if (!purge_fragmented_block(vb, vbq, &purge_list, false) &&
+ vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) {
unsigned long va_start = vb->va->va_start;
unsigned long s, e;
@@ -2250,15 +2291,18 @@ static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush)
start = min(s, start);
end = max(e, end);
+ /* Prevent that this is flushed again */
+ vb->dirty_min = VMAP_BBMAP_BITS;
+ vb->dirty_max = 0;
+
flush = 1;
}
spin_unlock(&vb->lock);
}
rcu_read_unlock();
}
+ free_purged_blocks(&purge_list);
- mutex_lock(&vmap_purge_lock);
- purge_fragmented_blocks_allcpus();
if (!__purge_vmap_area_lazy(start, end) && flush)
flush_tlb_kernel_range(start, end);
mutex_unlock(&vmap_purge_lock);
@@ -2899,10 +2943,16 @@ struct vmap_pfn_data {
static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private)
{
struct vmap_pfn_data *data = private;
+ unsigned long pfn = data->pfns[data->idx];
+ pte_t ptent;
- if (WARN_ON_ONCE(pfn_valid(data->pfns[data->idx])))
+ if (WARN_ON_ONCE(pfn_valid(pfn)))
return -EINVAL;
- *pte = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot));
+
+ ptent = pte_mkspecial(pfn_pte(pfn, data->prot));
+ set_pte_at(&init_mm, addr, pte, ptent);
+
+ data->idx++;
return 0;
}
@@ -3520,7 +3570,7 @@ static size_t zero_iter(struct iov_iter *iter, size_t count)
while (remains > 0) {
size_t num, copied;
- num = remains < PAGE_SIZE ? remains : PAGE_SIZE;
+ num = min_t(size_t, remains, PAGE_SIZE);
copied = copy_page_to_iter_nofault(ZERO_PAGE(0), 0, num, iter);
remains -= copied;
@@ -4151,7 +4201,7 @@ recovery:
overflow:
spin_unlock(&free_vmap_area_lock);
if (!purged) {
- purge_vmap_area_lazy();
+ reclaim_and_purge_vmap_areas();
purged = true;
/* Before "retry", check if we recover. */