Revert "mm: simplify code of swap.c"

This reverts commit d8505dee1a.

Chris Mason ended up chasing down some page allocation errors and pages
stuck waiting on the IO scheduler, and was able to narrow it down to two
commits: commit 744ed14427 ("mm: batch activate_page() to reduce lock
contention") and d8505dee1a ("mm: simplify code of swap.c").

This reverts the second one.

Reported-and-debugged-by: Chris Mason <chris.mason@oracle.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jens Axboe <jaxboe@fusionio.com>
Cc: linux-mm <linux-mm@kvack.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds 2011-01-17 14:42:34 -08:00
parent 7a608572a2
commit 83896fb5e5

101
mm/swap.c
View file

@ -178,13 +178,15 @@ void put_pages_list(struct list_head *pages)
}
EXPORT_SYMBOL(put_pages_list);
static void pagevec_lru_move_fn(struct pagevec *pvec,
void (*move_fn)(struct page *page, void *arg),
void *arg)
/*
* pagevec_move_tail() must be called with IRQ disabled.
* Otherwise this may cause nasty races.
*/
static void pagevec_move_tail(struct pagevec *pvec)
{
int i;
int pgmoved = 0;
struct zone *zone = NULL;
unsigned long flags = 0;
for (i = 0; i < pagevec_count(pvec); i++) {
struct page *page = pvec->pages[i];
@ -192,41 +194,21 @@ static void pagevec_lru_move_fn(struct pagevec *pvec,
if (pagezone != zone) {
if (zone)
spin_unlock_irqrestore(&zone->lru_lock, flags);
spin_unlock(&zone->lru_lock);
zone = pagezone;
spin_lock_irqsave(&zone->lru_lock, flags);
spin_lock(&zone->lru_lock);
}
if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
int lru = page_lru_base_type(page);
list_move_tail(&page->lru, &zone->lru[lru].list);
pgmoved++;
}
(*move_fn)(page, arg);
}
if (zone)
spin_unlock_irqrestore(&zone->lru_lock, flags);
release_pages(pvec->pages, pagevec_count(pvec), pvec->cold);
pagevec_reinit(pvec);
}
static void pagevec_move_tail_fn(struct page *page, void *arg)
{
int *pgmoved = arg;
struct zone *zone = page_zone(page);
if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
int lru = page_lru_base_type(page);
list_move_tail(&page->lru, &zone->lru[lru].list);
(*pgmoved)++;
}
}
/*
* pagevec_move_tail() must be called with IRQ disabled.
* Otherwise this may cause nasty races.
*/
static void pagevec_move_tail(struct pagevec *pvec)
{
int pgmoved = 0;
pagevec_lru_move_fn(pvec, pagevec_move_tail_fn, &pgmoved);
spin_unlock(&zone->lru_lock);
__count_vm_events(PGROTATED, pgmoved);
release_pages(pvec->pages, pvec->nr, pvec->cold);
pagevec_reinit(pvec);
}
/*
@ -234,7 +216,7 @@ static void pagevec_move_tail(struct pagevec *pvec)
* reclaim. If it still appears to be reclaimable, move it to the tail of the
* inactive list.
*/
void rotate_reclaimable_page(struct page *page)
void rotate_reclaimable_page(struct page *page)
{
if (!PageLocked(page) && !PageDirty(page) && !PageActive(page) &&
!PageUnevictable(page) && PageLRU(page)) {
@ -534,33 +516,44 @@ void lru_add_page_tail(struct zone* zone,
}
}
static void ____pagevec_lru_add_fn(struct page *page, void *arg)
{
enum lru_list lru = (enum lru_list)arg;
struct zone *zone = page_zone(page);
int file = is_file_lru(lru);
int active = is_active_lru(lru);
VM_BUG_ON(PageActive(page));
VM_BUG_ON(PageUnevictable(page));
VM_BUG_ON(PageLRU(page));
SetPageLRU(page);
if (active)
SetPageActive(page);
update_page_reclaim_stat(zone, page, file, active);
add_page_to_lru_list(zone, page, lru);
}
/*
* Add the passed pages to the LRU, then drop the caller's refcount
* on them. Reinitialises the caller's pagevec.
*/
void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru)
{
int i;
struct zone *zone = NULL;
VM_BUG_ON(is_unevictable_lru(lru));
pagevec_lru_move_fn(pvec, ____pagevec_lru_add_fn, (void *)lru);
for (i = 0; i < pagevec_count(pvec); i++) {
struct page *page = pvec->pages[i];
struct zone *pagezone = page_zone(page);
int file;
int active;
if (pagezone != zone) {
if (zone)
spin_unlock_irq(&zone->lru_lock);
zone = pagezone;
spin_lock_irq(&zone->lru_lock);
}
VM_BUG_ON(PageActive(page));
VM_BUG_ON(PageUnevictable(page));
VM_BUG_ON(PageLRU(page));
SetPageLRU(page);
active = is_active_lru(lru);
file = is_file_lru(lru);
if (active)
SetPageActive(page);
update_page_reclaim_stat(zone, page, file, active);
add_page_to_lru_list(zone, page, lru);
}
if (zone)
spin_unlock_irq(&zone->lru_lock);
release_pages(pvec->pages, pvec->nr, pvec->cold);
pagevec_reinit(pvec);
}
EXPORT_SYMBOL(____pagevec_lru_add);