}
}
+/*
+ * Isolate a page from LRU with optional get_page() pin.
+ * Assumes lru_lock already held and page already pinned.
+ */
+static bool __munlock_isolate_lru_page(struct page *page, bool getpage)
+{
+ if (PageLRU(page)) {
+ struct lruvec *lruvec;
+
+ lruvec = mem_cgroup_page_lruvec(page, page_zone(page));
+ if (getpage)
+ get_page(page);
+ ClearPageLRU(page);
+ del_page_from_lru_list(page, lruvec, page_lru(page));
+ return true;
+ }
+
+ return false;
+}
+
/*
* Finish munlock after successful page isolation
*
static void __munlock_isolation_failed(struct page *page)
{
if (PageUnevictable(page))
- count_vm_event(UNEVICTABLE_PGSTRANDED);
+ __count_vm_event(UNEVICTABLE_PGSTRANDED);
else
- count_vm_event(UNEVICTABLE_PGMUNLOCKED);
+ __count_vm_event(UNEVICTABLE_PGMUNLOCKED);
}
/**
unsigned int munlock_vma_page(struct page *page)
{
unsigned int nr_pages;
+ struct zone *zone = page_zone(page);
BUG_ON(!PageLocked(page));
- if (TestClearPageMlocked(page)) {
- nr_pages = hpage_nr_pages(page);
- mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
- if (!isolate_lru_page(page))
- __munlock_isolated_page(page);
- else
- __munlock_isolation_failed(page);
- } else {
- nr_pages = hpage_nr_pages(page);
- }
-
/*
- * Regardless of the original PageMlocked flag, we determine nr_pages
- * after touching the flag. This leaves a possible race with a THP page
- * split, such that a whole THP page was munlocked, but nr_pages == 1.
- * Returning a smaller mask due to that is OK, the worst that can
- * happen is subsequent useless scanning of the former tail pages.
- * The NR_MLOCK accounting can however become broken.
+ * Serialize with any parallel __split_huge_page_refcount() which
+ * might otherwise copy PageMlocked to part of the tail pages before
+ * we clear it in the head page. It also stabilizes hpage_nr_pages().
*/
+ spin_lock_irq(&zone->lru_lock);
+
+ nr_pages = hpage_nr_pages(page);
+ if (!TestClearPageMlocked(page))
+ goto unlock_out;
+
+ __mod_zone_page_state(zone, NR_MLOCK, -nr_pages);
+
+ if (__munlock_isolate_lru_page(page, true)) {
+ spin_unlock_irq(&zone->lru_lock);
+ __munlock_isolated_page(page);
+ goto out;
+ }
+ __munlock_isolation_failed(page);
+
+unlock_out:
+ spin_unlock_irq(&zone->lru_lock);
+
+out:
return nr_pages - 1;
}
static bool __putback_lru_fast_prepare(struct page *page, struct pagevec *pvec,
int *pgrescued)
{
- VM_BUG_ON(PageLRU(page));
- VM_BUG_ON(!PageLocked(page));
+ VM_BUG_ON_PAGE(PageLRU(page), page);
+ VM_BUG_ON_PAGE(!PageLocked(page), page);
if (page_mapcount(page) <= 1 && page_evictable(page)) {
pagevec_add(pvec, page);
struct page *page = pvec->pages[i];
if (TestClearPageMlocked(page)) {
- struct lruvec *lruvec;
- int lru;
-
- if (PageLRU(page)) {
- lruvec = mem_cgroup_page_lruvec(page, zone);
- lru = page_lru(page);
- /*
- * We already have pin from follow_page_mask()
- * so we can spare the get_page() here.
- */
- ClearPageLRU(page);
- del_page_from_lru_list(page, lruvec, lru);
- } else {
- __munlock_isolation_failed(page);
- goto skip_munlock;
- }
-
- } else {
-skip_munlock:
/*
- * We won't be munlocking this page in the next phase
- * but we still need to release the follow_page_mask()
- * pin. We cannot do it under lru_lock however. If it's
- * the last pin, __page_cache_release would deadlock.
+ * We already have pin from follow_page_mask()
+ * so we can spare the get_page() here.
*/
- pagevec_add(&pvec_putback, pvec->pages[i]);
- pvec->pages[i] = NULL;
+ if (__munlock_isolate_lru_page(page, false))
+ continue;
+ else
+ __munlock_isolation_failed(page);
}
+
+ /*
+ * We won't be munlocking this page in the next phase
+ * but we still need to release the follow_page_mask()
+ * pin. We cannot do it under lru_lock however. If it's
+ * the last pin, __page_cache_release() would deadlock.
+ */
+ pagevec_add(&pvec_putback, pvec->pages[i]);
+ pvec->pages[i] = NULL;
}
delta_munlocked = -nr + pagevec_count(&pvec_putback);
__mod_zone_page_state(zone, NR_MLOCK, delta_munlocked);
lru_add_drain_all(); /* flush pagevec */
- down_write(¤t->mm->mmap_sem);
len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
start &= PAGE_MASK;
- locked = len >> PAGE_SHIFT;
- locked += current->mm->locked_vm;
-
lock_limit = rlimit(RLIMIT_MEMLOCK);
lock_limit >>= PAGE_SHIFT;
+ locked = len >> PAGE_SHIFT;
+
+ down_write(¤t->mm->mmap_sem);
+
+ locked += current->mm->locked_vm;
/* check against resource limits */
if ((locked <= lock_limit) || capable(CAP_IPC_LOCK))
error = do_mlock(start, len, 1);
+
up_write(¤t->mm->mmap_sem);
if (!error)
error = __mm_populate(start, len, 0);
{
int ret;
- down_write(¤t->mm->mmap_sem);
len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
start &= PAGE_MASK;
+
+ down_write(¤t->mm->mmap_sem);
ret = do_mlock(start, len, 0);
up_write(¤t->mm->mmap_sem);
+
return ret;
}
if (flags & MCL_CURRENT)
lru_add_drain_all(); /* flush pagevec */
- down_write(¤t->mm->mmap_sem);
-
lock_limit = rlimit(RLIMIT_MEMLOCK);
lock_limit >>= PAGE_SHIFT;
ret = -ENOMEM;
+ down_write(¤t->mm->mmap_sem);
+
if (!(flags & MCL_CURRENT) || (current->mm->total_vm <= lock_limit) ||
capable(CAP_IPC_LOCK))
ret = do_mlockall(flags);
projects / karo-tx-linux.git / blobdiff