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oom: change all_unreclaimable zone member to flags 

Convert the int all_unreclaimable member of struct zone to unsigned long
flags.  This can now be used to specify several different zone flags such as
all_unreclaimable and reclaim_in_progress, which can now be removed and
converted to a per-zone flag.

Flags are set and cleared as follows:

	zone_set_flag(struct zone *zone, zone_flags_t flag)
	zone_clear_flag(struct zone *zone, zone_flags_t flag)

Defines the first zone flags, ZONE_ALL_UNRECLAIMABLE and ZONE_RECLAIM_LOCKED,
which have the same semantics as the old zone->all_unreclaimable and
zone->reclaim_in_progress, respectively.  Also converts all current users that
set or clear either flag to use the new interface.

Helper functions are defined to test the flags:

	int zone_is_all_unreclaimable(const struct zone *zone)
	int zone_is_reclaim_locked(const struct zone *zone)

All flag operators are of the atomic variety because there are currently
readers that are implemented that do not take zone->lock.

[akpm@linux-foundation.org: add needed include]
Cc: Andrea Arcangeli <andrea@suse.de>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Rientjes 2007-10-16 23:25:54 -07:00 committed by Linus Torvalds
parent 70e24bdf6d
commit e815af95f9
4 changed files with 43 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
include/linux/mmzone.h
View File

@ -7,6 +7,7 @@
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/bitops.h>
#include <linux/cache.h>
#include <linux/threads.h>
#include <linux/numa.h>
@ -262,10 +263,7 @@ struct zone {
unsigned long nr_scan_active;
unsigned long nr_scan_inactive;
unsigned long pages_scanned; /* since last reclaim */
int all_unreclaimable; /* All pages pinned */
/* A count of how many reclaimers are scanning this zone */
atomic_t reclaim_in_progress;
unsigned long flags; /* zone flags, see below */
/* Zone statistics */
atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
@ -343,6 +341,29 @@ struct zone {
const char *name;
} ____cacheline_internodealigned_in_smp;
typedef enum {
ZONE_ALL_UNRECLAIMABLE, /* all pages pinned */
ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */
} zone_flags_t;
static inline void zone_set_flag(struct zone *zone, zone_flags_t flag)
{
set_bit(flag, &zone->flags);
}
static inline void zone_clear_flag(struct zone *zone, zone_flags_t flag)
{
clear_bit(flag, &zone->flags);
}
static inline int zone_is_all_unreclaimable(const struct zone *zone)
{
return test_bit(ZONE_ALL_UNRECLAIMABLE, &zone->flags);
}
static inline int zone_is_reclaim_locked(const struct zone *zone)
{
return test_bit(ZONE_RECLAIM_LOCKED, &zone->flags);
}
/*
* The "priority" of VM scanning is how much of the queues we will scan in one
* go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the

8
mm/page_alloc.c
View File

@ -490,7 +490,7 @@ static void free_pages_bulk(struct zone *zone, int count,
struct list_head *list, int order)
{
spin_lock(&zone->lock);
zone->all_unreclaimable = 0;
zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
zone->pages_scanned = 0;
while (count--) {
struct page *page;
@ -507,7 +507,7 @@ static void free_pages_bulk(struct zone *zone, int count,
static void free_one_page(struct zone *zone, struct page *page, int order)
{
spin_lock(&zone->lock);
zone->all_unreclaimable = 0;
zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
zone->pages_scanned = 0;
__free_one_page(page, zone, order);
spin_unlock(&zone->lock);
@ -1851,7 +1851,7 @@ void show_free_areas(void)
K(zone_page_state(zone, NR_INACTIVE)),
K(zone->present_pages),
zone->pages_scanned,
(zone->all_unreclaimable ? "yes" : "no")
(zone_is_all_unreclaimable(zone) ? "yes" : "no")
);
printk("lowmem_reserve[]:");
for (i = 0; i < MAX_NR_ZONES; i++)
@ -3372,7 +3372,7 @@ static void __meminit free_area_init_core(struct pglist_data *pgdat,
zone->nr_scan_active = 0;
zone->nr_scan_inactive = 0;
zap_zone_vm_stats(zone);
atomic_set(&zone->reclaim_in_progress, 0);
zone->flags = 0;
if (!size)
continue;

25
mm/vmscan.c
View File

@ -1108,7 +1108,7 @@ static unsigned long shrink_zone(int priority, struct zone *zone,
unsigned long nr_to_scan;
unsigned long nr_reclaimed = 0;
atomic_inc(&zone->reclaim_in_progress);
zone_set_flag(zone, ZONE_RECLAIM_LOCKED);
/*
* Add one to `nr_to_scan' just to make sure that the kernel will
@ -1149,7 +1149,7 @@ static unsigned long shrink_zone(int priority, struct zone *zone,
throttle_vm_writeout(sc->gfp_mask);
atomic_dec(&zone->reclaim_in_progress);
zone_clear_flag(zone, ZONE_RECLAIM_LOCKED);
return nr_reclaimed;
}
@ -1187,7 +1187,7 @@ static unsigned long shrink_zones(int priority, struct zone **zones,
note_zone_scanning_priority(zone, priority);
if (zone->all_unreclaimable && priority != DEF_PRIORITY)
if (zone_is_all_unreclaimable(zone) && priority != DEF_PRIORITY)
continue; /* Let kswapd poll it */
sc->all_unreclaimable = 0;
@ -1368,7 +1368,8 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order)
if (!populated_zone(zone))
continue;
if (zone->all_unreclaimable && priority != DEF_PRIORITY)
if (zone_is_all_unreclaimable(zone) &&
priority != DEF_PRIORITY)
continue;
if (!zone_watermark_ok(zone, order, zone->pages_high,
@ -1403,7 +1404,8 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order)
if (!populated_zone(zone))
continue;
if (zone->all_unreclaimable && priority != DEF_PRIORITY)
if (zone_is_all_unreclaimable(zone) &&
priority != DEF_PRIORITY)
continue;
if (!zone_watermark_ok(zone, order, zone->pages_high,
@ -1424,12 +1426,13 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order)
lru_pages);
nr_reclaimed += reclaim_state->reclaimed_slab;
total_scanned += sc.nr_scanned;
if (zone->all_unreclaimable)
if (zone_is_all_unreclaimable(zone))
continue;
if (nr_slab == 0 && zone->pages_scanned >=
(zone_page_state(zone, NR_ACTIVE)
+ zone_page_state(zone, NR_INACTIVE)) * 6)
zone->all_unreclaimable = 1;
zone_set_flag(zone,
ZONE_ALL_UNRECLAIMABLE);
/*
* If we've done a decent amount of scanning and
* the reclaim ratio is low, start doing writepage
@ -1595,7 +1598,7 @@ static unsigned long shrink_all_zones(unsigned long nr_pages, int prio,
if (!populated_zone(zone))
continue;
if (zone->all_unreclaimable && prio != DEF_PRIORITY)
if (zone_is_all_unreclaimable(zone) && prio != DEF_PRIORITY)
continue;
/* For pass = 0 we don't shrink the active list */
@ -1919,10 +1922,8 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
* not have reclaimable pages and if we should not delay the allocation
* then do not scan.
*/
if (!(gfp_mask & __GFP_WAIT) ||
zone->all_unreclaimable ||
atomic_read(&zone->reclaim_in_progress) > 0 ||
(current->flags & PF_MEMALLOC))
if (!(gfp_mask & __GFP_WAIT) || zone_is_all_unreclaimable(zone) ||
zone_is_reclaim_locked(zone) || (current->flags & PF_MEMALLOC))
return 0;
/*

2
mm/vmstat.c
View File

@ -704,7 +704,7 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
"\n all_unreclaimable: %u"
"\n prev_priority: %i"
"\n start_pfn: %lu",
zone->all_unreclaimable,
zone_is_all_unreclaimable(zone),
zone->prev_priority,
zone->zone_start_pfn);
seq_putc(m, '\n');