[RFC 4/9] Atomic reclaim: Save irq flags in vmscan.c

Christoph Lameter
2007-08-14T15:38:59Z

[-- Attachment #1: vmscan_irqsave --]
[-- Type: text/plain, Size: 4471 bytes --]

Reclaim can be called with interrupts disabled in atomic reclaim.
vmscan.c is currently using spinlock_irq(). Switch to spin_lock_irqsave().

Signed-off-by: Christoph Lameter <clameter@sgi.com>

---
mm/vmscan.c | 36 +++++++++++++++++++-----------------
1 file changed, 19 insertions(+), 17 deletions(-)

Index: linux-2.6/mm/vmscan.c
===================================================================
--- linux-2.6.orig/mm/vmscan.c 2007-08-14 07:34:25.000000000 -0700
+++ linux-2.6/mm/vmscan.c 2007-08-14 07:34:55.000000000 -0700
@@ -775,11 +775,12 @@ static unsigned long shrink_inactive_lis
struct pagevec pvec;
unsigned long nr_scanned = 0;
unsigned long nr_reclaimed = 0;
+ unsigned long flags;

pagevec_init(&pvec, 1);

lru_add_drain();
- spin_lock_irq(&zone->lru_lock);
+ spin_lock_irqsave(&zone->lru_lock, flags);
do {
struct page *page;
unsigned long nr_taken;
@@ -798,12 +799,12 @@ static unsigned long shrink_inactive_lis
__mod_zone_page_state(zone, NR_INACTIVE,
-(nr_taken - nr_active));
zone->pages_scanned += nr_scan;
- spin_unlock_irq(&zone->lru_lock);
+ spin_unlock_irqrestore(&zone->lru_lock, flags);

nr_scanned += nr_scan;
nr_freed = shrink_page_list(&page_list, sc);
nr_reclaimed += nr_freed;
- local_irq_disable();
+ local_irq_save(flags);
if (current_is_kswapd()) {
__count_zone_vm_events(PGSCAN_KSWAPD, zone, nr_scan);
__count_vm_events(KSWAPD_STEAL, nr_freed);
@@ -828,15 +829,15 @@ static unsigned long shrink_inactive_lis
else
add_page_to_inactive_list(zone, page);
if (!pagevec_add(&pvec, page)) {
- spin_unlock_irq(&zone->lru_lock);
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
__pagevec_release(&pvec);
- spin_lock_irq(&zone->lru_lock);
+ spin_lock_irqsave(&zone->lru_lock, flags);
}
}
} while (nr_scanned < max_scan);
- spin_unlock(&zone->lru_lock);
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
done:
- local_irq_enable();
+ local_irq_restore(flags);
pagevec_release(&pvec);
return nr_reclaimed;
}
@@ -890,6 +891,7 @@ static void shrink_active_list(unsigned
struct page *page;
struct pagevec pvec;
int reclaim_mapped = 0;
+ unsigned long flags;

if (sc->may_swap) {
long mapped_ratio;
@@ -939,12 +941,12 @@ force_reclaim_mapped:
}

lru_add_drain();
- spin_lock_irq(&zone->lru_lock);
+ spin_lock_irqsave(&zone->lru_lock, flags);
pgmoved = isolate_lru_pages(nr_pages, &zone->active_list,
&l_hold, &pgscanned, sc->order, ISOLATE_ACTIVE);
zone->pages_scanned += pgscanned;
__mod_zone_page_state(zone, NR_ACTIVE, -pgmoved);
- spin_unlock_irq(&zone->lru_lock);
+ spin_unlock_irqrestore(&zone->lru_lock, flags);

while (!list_empty(&l_hold)) {
reclaim_resched(sc);
@@ -963,7 +965,7 @@ force_reclaim_mapped:

pagevec_init(&pvec, 1);
pgmoved = 0;
- spin_lock_irq(&zone->lru_lock);
+ spin_lock_irqsave(&zone->lru_lock, flags);
while (!list_empty(&l_inactive)) {
page = lru_to_page(&l_inactive);
prefetchw_prev_lru_page(page, &l_inactive, flags);
@@ -976,21 +978,21 @@ force_reclaim_mapped:
pgmoved++;
if (!pagevec_add(&pvec, page)) {
__mod_zone_page_state(zone, NR_INACTIVE, pgmoved);
- spin_unlock_irq(&zone->lru_lock);
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
pgdeactivate += pgmoved;
pgmoved = 0;
if (buffer_heads_over_limit)
pagevec_strip(&pvec);
__pagevec_release(&pvec);
- spin_lock_irq(&zone->lru_lock);
+ spin_lock_irqsave(&zone->lru_lock, flags);
}
}
__mod_zone_page_state(zone, NR_INACTIVE, pgmoved);
pgdeactivate += pgmoved;
if (buffer_heads_over_limit) {
- spin_unlock_irq(&zone->lru_lock);
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
pagevec_strip(&pvec);
- spin_lock_irq(&zone->lru_lock);
+ spin_lock_irqsave(&zone->lru_lock, flags);
}

pgmoved = 0;
@@ -1005,16 +1007,16 @@ force_reclaim_mapped:
if (!pagevec_add(&pvec, page)) {
__mod_zone_page_state(zone, NR_ACTIVE, pgmoved);
pgmoved = 0;
- spin_unlock_irq(&zone->lru_lock);
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
__pagevec_release(&pvec);
- spin_lock_irq(&zone->lru_lock);
+ spin_lock_irqsave(&zone->lru_lock, flags);
}
}
__mod_zone_page_state(zone, NR_ACTIVE, pgmoved);

__count_zone_vm_events(PGREFILL, zone, pgscanned);
__count_vm_events(PGDEACTIVATE, pgdeactivate);
- spin_unlock_irq(&zone->lru_lock);
+ spin_unlock_irqrestore(&zone->lru_lock, flags);

pagevec_release(&pvec);
}

--