* be enough slots to hold all possible variants
*/
unsigned long slot[BUDDY_MASK + 1];
- unsigned long pool; /* back link + flags */
+ unsigned long pool; /* back link */
rwlock_t lock;
};
#define HANDLE_FLAG_MASK (0x03)
* handle flags, go under HANDLE_FLAG_MASK
*/
enum z3fold_handle_flags {
- HANDLES_ORPHANED = 0,
+ HANDLES_NOFREE = 0,
};
/*
z3fold_page_unlock(zhdr);
}
-static inline void free_handle(unsigned long handle)
+static inline void free_handle(unsigned long handle, struct z3fold_header *zhdr)
{
struct z3fold_buddy_slots *slots;
- struct z3fold_header *zhdr;
int i;
bool is_free;
if (WARN_ON(*(unsigned long *)handle == 0))
return;
- zhdr = handle_to_z3fold_header(handle);
slots = handle_to_slots(handle);
write_lock(&slots->lock);
*(unsigned long *)handle = 0;
- if (zhdr->slots == slots) {
+
+ if (test_bit(HANDLES_NOFREE, &slots->pool)) {
write_unlock(&slots->lock);
return; /* simple case, nothing else to do */
}
- /* we are freeing a foreign handle if we are here */
- zhdr->foreign_handles--;
+ if (zhdr->slots != slots)
+ zhdr->foreign_handles--;
+
is_free = true;
- if (!test_bit(HANDLES_ORPHANED, &slots->pool)) {
- write_unlock(&slots->lock);
- return;
- }
for (i = 0; i <= BUDDY_MASK; i++) {
if (slots->slot[i]) {
is_free = false;
if (is_free) {
struct z3fold_pool *pool = slots_to_pool(slots);
+ if (zhdr->slots == slots)
+ zhdr->slots = NULL;
kmem_cache_free(pool->c_handle, slots);
}
}
{
struct page *page = virt_to_page(zhdr);
struct z3fold_pool *pool = zhdr_to_pool(zhdr);
- bool is_free = true;
- int i;
WARN_ON(!list_empty(&zhdr->buddy));
set_bit(PAGE_STALE, &page->private);
list_del_init(&page->lru);
spin_unlock(&pool->lock);
- /* If there are no foreign handles, free the handles array */
- read_lock(&zhdr->slots->lock);
- for (i = 0; i <= BUDDY_MASK; i++) {
- if (zhdr->slots->slot[i]) {
- is_free = false;
- break;
- }
- }
- if (!is_free)
- set_bit(HANDLES_ORPHANED, &zhdr->slots->pool);
- read_unlock(&zhdr->slots->lock);
-
- if (is_free)
- kmem_cache_free(pool->c_handle, zhdr->slots);
-
if (locked)
z3fold_page_unlock(zhdr);
{
if (zhdr->first_chunks == 0 || zhdr->last_chunks == 0 ||
zhdr->middle_chunks == 0) {
- struct list_head *unbuddied = get_cpu_ptr(pool->unbuddied);
-
+ struct list_head *unbuddied;
int freechunks = num_free_chunks(zhdr);
+
+ migrate_disable();
+ unbuddied = this_cpu_ptr(pool->unbuddied);
spin_lock(&pool->lock);
list_add(&zhdr->buddy, &unbuddied[freechunks]);
spin_unlock(&pool->lock);
zhdr->cpu = smp_processor_id();
- put_cpu_ptr(pool->unbuddied);
+ migrate_enable();
+ }
+}
+
+static inline enum buddy get_free_buddy(struct z3fold_header *zhdr, int chunks)
+{
+ enum buddy bud = HEADLESS;
+
+ if (zhdr->middle_chunks) {
+ if (!zhdr->first_chunks &&
+ chunks <= zhdr->start_middle - ZHDR_CHUNKS)
+ bud = FIRST;
+ else if (!zhdr->last_chunks)
+ bud = LAST;
+ } else {
+ if (!zhdr->first_chunks)
+ bud = FIRST;
+ else if (!zhdr->last_chunks)
+ bud = LAST;
+ else
+ bud = MIDDLE;
}
+
+ return bud;
}
static inline void *mchunk_memmove(struct z3fold_header *zhdr,
if (WARN_ON(new_zhdr == zhdr))
goto out_fail;
- if (new_zhdr->first_chunks == 0) {
- if (new_zhdr->middle_chunks != 0 &&
- chunks >= new_zhdr->start_middle) {
- new_bud = LAST;
- } else {
- new_bud = FIRST;
- }
- } else if (new_zhdr->last_chunks == 0) {
- new_bud = LAST;
- } else if (new_zhdr->middle_chunks == 0) {
- new_bud = MIDDLE;
- }
+ new_bud = get_free_buddy(new_zhdr, chunks);
q = new_zhdr;
switch (new_bud) {
case FIRST:
return;
}
- if (unlikely(PageIsolated(page) ||
- test_bit(PAGE_CLAIMED, &page->private) ||
- test_bit(PAGE_STALE, &page->private))) {
+ if (test_bit(PAGE_STALE, &page->private) ||
+ test_and_set_bit(PAGE_CLAIMED, &page->private)) {
z3fold_page_unlock(zhdr);
return;
}
zhdr->mapped_count == 0 && compact_single_buddy(zhdr)) {
if (kref_put(&zhdr->refcount, release_z3fold_page_locked))
atomic64_dec(&pool->pages_nr);
- else
+ else {
+ clear_bit(PAGE_CLAIMED, &page->private);
z3fold_page_unlock(zhdr);
+ }
return;
}
z3fold_compact_page(zhdr);
add_to_unbuddied(pool, zhdr);
+ clear_bit(PAGE_CLAIMED, &page->private);
z3fold_page_unlock(zhdr);
}
int chunks = size_to_chunks(size), i;
lookup:
+ migrate_disable();
/* First, try to find an unbuddied z3fold page. */
- unbuddied = get_cpu_ptr(pool->unbuddied);
+ unbuddied = this_cpu_ptr(pool->unbuddied);
for_each_unbuddied_list(i, chunks) {
struct list_head *l = &unbuddied[i];
!z3fold_page_trylock(zhdr)) {
spin_unlock(&pool->lock);
zhdr = NULL;
- put_cpu_ptr(pool->unbuddied);
+ migrate_enable();
if (can_sleep)
cond_resched();
goto lookup;
test_bit(PAGE_CLAIMED, &page->private)) {
z3fold_page_unlock(zhdr);
zhdr = NULL;
- put_cpu_ptr(pool->unbuddied);
+ migrate_enable();
if (can_sleep)
cond_resched();
goto lookup;
kref_get(&zhdr->refcount);
break;
}
- put_cpu_ptr(pool->unbuddied);
+ migrate_enable();
if (!zhdr) {
int cpu;
}
}
+ if (zhdr && !zhdr->slots)
+ zhdr->slots = alloc_slots(pool,
+ can_sleep ? GFP_NOIO : GFP_ATOMIC);
return zhdr;
}
retry:
zhdr = __z3fold_alloc(pool, size, can_sleep);
if (zhdr) {
- if (zhdr->first_chunks == 0) {
- if (zhdr->middle_chunks != 0 &&
- chunks >= zhdr->start_middle)
- bud = LAST;
- else
- bud = FIRST;
- } else if (zhdr->last_chunks == 0)
- bud = LAST;
- else if (zhdr->middle_chunks == 0)
- bud = MIDDLE;
- else {
+ bud = get_free_buddy(zhdr, chunks);
+ if (bud == HEADLESS) {
if (kref_put(&zhdr->refcount,
release_z3fold_page_locked))
atomic64_dec(&pool->pages_nr);
pr_err("%s: unknown bud %d\n", __func__, bud);
WARN_ON(1);
put_z3fold_header(zhdr);
- clear_bit(PAGE_CLAIMED, &page->private);
return;
}
if (!page_claimed)
- free_handle(handle);
+ free_handle(handle, zhdr);
if (kref_put(&zhdr->refcount, release_z3fold_page_locked_list)) {
atomic64_dec(&pool->pages_nr);
return;
z3fold_page_unlock(zhdr);
return;
}
- if (unlikely(PageIsolated(page)) ||
- test_and_set_bit(NEEDS_COMPACTING, &page->private)) {
+ if (test_and_set_bit(NEEDS_COMPACTING, &page->private)) {
put_z3fold_header(zhdr);
clear_bit(PAGE_CLAIMED, &page->private);
return;
struct page *page = NULL;
struct list_head *pos;
unsigned long first_handle = 0, middle_handle = 0, last_handle = 0;
+ struct z3fold_buddy_slots slots __attribute__((aligned(SLOTS_ALIGN)));
+
+ rwlock_init(&slots.lock);
+ slots.pool = (unsigned long)pool | (1 << HANDLES_NOFREE);
spin_lock(&pool->lock);
if (!pool->ops || !pool->ops->evict || retries == 0) {
list_for_each_prev(pos, &pool->lru) {
page = list_entry(pos, struct page, lru);
- /* this bit could have been set by free, in which case
- * we pass over to the next page in the pool.
- */
- if (test_and_set_bit(PAGE_CLAIMED, &page->private)) {
- page = NULL;
- continue;
- }
-
- if (unlikely(PageIsolated(page))) {
- clear_bit(PAGE_CLAIMED, &page->private);
- page = NULL;
- continue;
- }
zhdr = page_address(page);
if (test_bit(PAGE_HEADLESS, &page->private))
break;
+ if (kref_get_unless_zero(&zhdr->refcount) == 0) {
+ zhdr = NULL;
+ break;
+ }
if (!z3fold_page_trylock(zhdr)) {
- clear_bit(PAGE_CLAIMED, &page->private);
+ if (kref_put(&zhdr->refcount,
+ release_z3fold_page))
+ atomic64_dec(&pool->pages_nr);
zhdr = NULL;
continue; /* can't evict at this point */
}
- if (zhdr->foreign_handles) {
- clear_bit(PAGE_CLAIMED, &page->private);
- z3fold_page_unlock(zhdr);
+
+ /* test_and_set_bit is of course atomic, but we still
+ * need to do it under page lock, otherwise checking
+ * that bit in __z3fold_alloc wouldn't make sense
+ */
+ if (zhdr->foreign_handles ||
+ test_and_set_bit(PAGE_CLAIMED, &page->private)) {
+ if (kref_put(&zhdr->refcount,
+ release_z3fold_page))
+ atomic64_dec(&pool->pages_nr);
+ else
+ z3fold_page_unlock(zhdr);
zhdr = NULL;
continue; /* can't evict such page */
}
- kref_get(&zhdr->refcount);
list_del_init(&zhdr->buddy);
zhdr->cpu = -1;
break;
first_handle = 0;
last_handle = 0;
middle_handle = 0;
+ memset(slots.slot, 0, sizeof(slots.slot));
if (zhdr->first_chunks)
- first_handle = encode_handle(zhdr, FIRST);
+ first_handle = __encode_handle(zhdr, &slots,
+ FIRST);
if (zhdr->middle_chunks)
- middle_handle = encode_handle(zhdr, MIDDLE);
+ middle_handle = __encode_handle(zhdr, &slots,
+ MIDDLE);
if (zhdr->last_chunks)
- last_handle = encode_handle(zhdr, LAST);
+ last_handle = __encode_handle(zhdr, &slots,
+ LAST);
/*
* it's safe to unlock here because we hold a
* reference to this page
ret = pool->ops->evict(pool, middle_handle);
if (ret)
goto next;
- free_handle(middle_handle);
}
if (first_handle) {
ret = pool->ops->evict(pool, first_handle);
if (ret)
goto next;
- free_handle(first_handle);
}
if (last_handle) {
ret = pool->ops->evict(pool, last_handle);
if (ret)
goto next;
- free_handle(last_handle);
}
next:
if (test_bit(PAGE_HEADLESS, &page->private)) {
spin_unlock(&pool->lock);
clear_bit(PAGE_CLAIMED, &page->private);
} else {
+ struct z3fold_buddy_slots *slots = zhdr->slots;
z3fold_page_lock(zhdr);
if (kref_put(&zhdr->refcount,
release_z3fold_page_locked)) {
+ kmem_cache_free(pool->c_handle, slots);
atomic64_dec(&pool->pages_nr);
return 0;
}
VM_BUG_ON_PAGE(!PageMovable(page), page);
VM_BUG_ON_PAGE(PageIsolated(page), page);
- if (test_bit(PAGE_HEADLESS, &page->private) ||
- test_bit(PAGE_CLAIMED, &page->private))
+ if (test_bit(PAGE_HEADLESS, &page->private))
return false;
zhdr = page_address(page);
if (zhdr->mapped_count != 0 || zhdr->foreign_handles != 0)
goto out;
+ if (test_and_set_bit(PAGE_CLAIMED, &page->private))
+ goto out;
pool = zhdr_to_pool(zhdr);
spin_lock(&pool->lock);
if (!list_empty(&zhdr->buddy))
VM_BUG_ON_PAGE(!PageMovable(page), page);
VM_BUG_ON_PAGE(!PageIsolated(page), page);
+ VM_BUG_ON_PAGE(!test_bit(PAGE_CLAIMED, &page->private), page);
VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
zhdr = page_address(page);
pool = zhdr_to_pool(zhdr);
- if (!z3fold_page_trylock(zhdr)) {
+ if (!z3fold_page_trylock(zhdr))
return -EAGAIN;
- }
if (zhdr->mapped_count != 0 || zhdr->foreign_handles != 0) {
z3fold_page_unlock(zhdr);
+ clear_bit(PAGE_CLAIMED, &page->private);
return -EBUSY;
}
if (work_pending(&zhdr->work)) {
queue_work_on(new_zhdr->cpu, pool->compact_wq, &new_zhdr->work);
page_mapcount_reset(page);
+ clear_bit(PAGE_CLAIMED, &page->private);
put_page(page);
return 0;
}
spin_lock(&pool->lock);
list_add(&page->lru, &pool->lru);
spin_unlock(&pool->lock);
+ clear_bit(PAGE_CLAIMED, &page->private);
z3fold_page_unlock(zhdr);
}
projects / linux-2.6-microblaze.git / blobdiff