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-rw-r--r--mm/swap.c150
1 files changed, 95 insertions, 55 deletions
diff --git a/mm/swap.c b/mm/swap.c
index 4a1d0d2c52fa..759c3caf44bd 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -31,6 +31,7 @@
#include <linux/memcontrol.h>
#include <linux/gfp.h>
#include <linux/uio.h>
+#include <linux/hugetlb.h>
#include "internal.h"
@@ -81,6 +82,19 @@ static void __put_compound_page(struct page *page)
static void put_compound_page(struct page *page)
{
+ /*
+ * hugetlbfs pages cannot be split from under us. If this is a
+ * hugetlbfs page, check refcount on head page and release the page if
+ * the refcount becomes zero.
+ */
+ if (PageHuge(page)) {
+ page = compound_head(page);
+ if (put_page_testzero(page))
+ __put_compound_page(page);
+
+ return;
+ }
+
if (unlikely(PageTail(page))) {
/* __split_huge_page_refcount can run under us */
struct page *page_head = compound_trans_head(page);
@@ -184,38 +198,51 @@ bool __get_page_tail(struct page *page)
* proper PT lock that already serializes against
* split_huge_page().
*/
- unsigned long flags;
bool got = false;
- struct page *page_head = compound_trans_head(page);
+ struct page *page_head;
- if (likely(page != page_head && get_page_unless_zero(page_head))) {
+ /*
+ * If this is a hugetlbfs page it cannot be split under us. Simply
+ * increment refcount for the head page.
+ */
+ if (PageHuge(page)) {
+ page_head = compound_head(page);
+ atomic_inc(&page_head->_count);
+ got = true;
+ } else {
+ unsigned long flags;
- /* Ref to put_compound_page() comment. */
- if (PageSlab(page_head)) {
+ page_head = compound_trans_head(page);
+ if (likely(page != page_head &&
+ get_page_unless_zero(page_head))) {
+
+ /* Ref to put_compound_page() comment. */
+ if (PageSlab(page_head)) {
+ if (likely(PageTail(page))) {
+ __get_page_tail_foll(page, false);
+ return true;
+ } else {
+ put_page(page_head);
+ return false;
+ }
+ }
+
+ /*
+ * page_head wasn't a dangling pointer but it
+ * may not be a head page anymore by the time
+ * we obtain the lock. That is ok as long as it
+ * can't be freed from under us.
+ */
+ flags = compound_lock_irqsave(page_head);
+ /* here __split_huge_page_refcount won't run anymore */
if (likely(PageTail(page))) {
__get_page_tail_foll(page, false);
- return true;
- } else {
- put_page(page_head);
- return false;
+ got = true;
}
+ compound_unlock_irqrestore(page_head, flags);
+ if (unlikely(!got))
+ put_page(page_head);
}
-
- /*
- * page_head wasn't a dangling pointer but it
- * may not be a head page anymore by the time
- * we obtain the lock. That is ok as long as it
- * can't be freed from under us.
- */
- flags = compound_lock_irqsave(page_head);
- /* here __split_huge_page_refcount won't run anymore */
- if (likely(PageTail(page))) {
- __get_page_tail_foll(page, false);
- got = true;
- }
- compound_unlock_irqrestore(page_head, flags);
- if (unlikely(!got))
- put_page(page_head);
}
return got;
}
@@ -405,6 +432,11 @@ static void activate_page_drain(int cpu)
pagevec_lru_move_fn(pvec, __activate_page, NULL);
}
+static bool need_activate_page_drain(int cpu)
+{
+ return pagevec_count(&per_cpu(activate_page_pvecs, cpu)) != 0;
+}
+
void activate_page(struct page *page)
{
if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
@@ -422,6 +454,11 @@ static inline void activate_page_drain(int cpu)
{
}
+static bool need_activate_page_drain(int cpu)
+{
+ return false;
+}
+
void activate_page(struct page *page)
{
struct zone *zone = page_zone(page);
@@ -512,12 +549,7 @@ EXPORT_SYMBOL(__lru_cache_add);
*/
void lru_cache_add(struct page *page)
{
- if (PageActive(page)) {
- VM_BUG_ON(PageUnevictable(page));
- } else if (PageUnevictable(page)) {
- VM_BUG_ON(PageActive(page));
- }
-
+ VM_BUG_ON(PageActive(page) && PageUnevictable(page));
VM_BUG_ON(PageLRU(page));
__lru_cache_add(page);
}
@@ -539,6 +571,7 @@ void add_page_to_unevictable_list(struct page *page)
spin_lock_irq(&zone->lru_lock);
lruvec = mem_cgroup_page_lruvec(page, zone);
+ ClearPageActive(page);
SetPageUnevictable(page);
SetPageLRU(page);
add_page_to_lru_list(page, lruvec, LRU_UNEVICTABLE);
@@ -678,12 +711,36 @@ static void lru_add_drain_per_cpu(struct work_struct *dummy)
lru_add_drain();
}
-/*
- * Returns 0 for success
- */
-int lru_add_drain_all(void)
+static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work);
+
+void lru_add_drain_all(void)
{
- return schedule_on_each_cpu(lru_add_drain_per_cpu);
+ static DEFINE_MUTEX(lock);
+ static struct cpumask has_work;
+ int cpu;
+
+ mutex_lock(&lock);
+ get_online_cpus();
+ cpumask_clear(&has_work);
+
+ for_each_online_cpu(cpu) {
+ struct work_struct *work = &per_cpu(lru_add_drain_work, cpu);
+
+ if (pagevec_count(&per_cpu(lru_add_pvec, cpu)) ||
+ pagevec_count(&per_cpu(lru_rotate_pvecs, cpu)) ||
+ pagevec_count(&per_cpu(lru_deactivate_pvecs, cpu)) ||
+ need_activate_page_drain(cpu)) {
+ INIT_WORK(work, lru_add_drain_per_cpu);
+ schedule_work_on(cpu, work);
+ cpumask_set_cpu(cpu, &has_work);
+ }
+ }
+
+ for_each_cpu(cpu, &has_work)
+ flush_work(&per_cpu(lru_add_drain_work, cpu));
+
+ put_online_cpus();
+ mutex_unlock(&lock);
}
/*
@@ -774,8 +831,6 @@ EXPORT_SYMBOL(__pagevec_release);
void lru_add_page_tail(struct page *page, struct page *page_tail,
struct lruvec *lruvec, struct list_head *list)
{
- int uninitialized_var(active);
- enum lru_list lru;
const int file = 0;
VM_BUG_ON(!PageHead(page));
@@ -787,20 +842,6 @@ void lru_add_page_tail(struct page *page, struct page *page_tail,
if (!list)
SetPageLRU(page_tail);
- if (page_evictable(page_tail)) {
- if (PageActive(page)) {
- SetPageActive(page_tail);
- active = 1;
- lru = LRU_ACTIVE_ANON;
- } else {
- active = 0;
- lru = LRU_INACTIVE_ANON;
- }
- } else {
- SetPageUnevictable(page_tail);
- lru = LRU_UNEVICTABLE;
- }
-
if (likely(PageLRU(page)))
list_add_tail(&page_tail->lru, &page->lru);
else if (list) {
@@ -816,13 +857,13 @@ void lru_add_page_tail(struct page *page, struct page *page_tail,
* Use the standard add function to put page_tail on the list,
* but then correct its position so they all end up in order.
*/
- add_page_to_lru_list(page_tail, lruvec, lru);
+ add_page_to_lru_list(page_tail, lruvec, page_lru(page_tail));
list_head = page_tail->lru.prev;
list_move_tail(&page_tail->lru, list_head);
}
if (!PageUnevictable(page))
- update_page_reclaim_stat(lruvec, file, active);
+ update_page_reclaim_stat(lruvec, file, PageActive(page_tail));
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
@@ -833,7 +874,6 @@ static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec,
int active = PageActive(page);
enum lru_list lru = page_lru(page);
- VM_BUG_ON(PageUnevictable(page));
VM_BUG_ON(PageLRU(page));
SetPageLRU(page);
generated by cgit v1.2.3 (git 2.39.0) at 2025-01-16 02:59:05 +0300