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Message-Id: <20100114103332.D71B.A69D9226@jp.fujitsu.com>
Date: Thu, 14 Jan 2010 10:35:03 +0900 (JST)
From: KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
To: LKML <linux-kernel@...r.kernel.org>, linux-mm <linux-mm@...ck.org>,
Andrew Morton <akpm@...ux-foundation.org>,
David Rientjes <rientjes@...gle.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
Minchan Kim <minchan.kim@...il.com>,
Wu Fengguang <fengguang.wu@...el.com>,
Huang Shijie <shijie8@...il.com>
Cc: kosaki.motohiro@...fujitsu.com
Subject: [resend][PATCH] mm: Restore zone->all_unreclaimable to independence word
commit e815af95 (change all_unreclaimable zone member to flags) chage
all_unreclaimable member to bit flag. but It have undesireble side
effect.
free_one_page() is one of most hot path in linux kernel and increasing
atomic ops in it can reduce kernel performance a bit.
Thus, this patch revert such commit partially. at least
all_unreclaimable shouldn't share memory word with other zone flags.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
---
include/linux/mmzone.h | 7 +------
mm/page_alloc.c | 6 +++---
mm/vmscan.c | 20 ++++++++------------
mm/vmstat.c | 2 +-
4 files changed, 13 insertions(+), 22 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 30fe668..4f0c6f1 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -341,6 +341,7 @@ struct zone {
unsigned long pages_scanned; /* since last reclaim */
unsigned long flags; /* zone flags, see below */
+ int all_unreclaimable; /* All pages pinned */
/* Zone statistics */
atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
@@ -425,7 +426,6 @@ struct zone {
} ____cacheline_internodealigned_in_smp;
typedef enum {
- ZONE_ALL_UNRECLAIMABLE, /* all pages pinned */
ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */
ZONE_OOM_LOCKED, /* zone is in OOM killer zonelist */
} zone_flags_t;
@@ -445,11 +445,6 @@ 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);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4e9f5cc..19a5b0e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -530,7 +530,7 @@ static void free_pcppages_bulk(struct zone *zone, int count,
int batch_free = 0;
spin_lock(&zone->lock);
- zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
+ zone->all_unreclaimable = 0;
zone->pages_scanned = 0;
__mod_zone_page_state(zone, NR_FREE_PAGES, count);
@@ -567,7 +567,7 @@ static void free_one_page(struct zone *zone, struct page *page, int order,
int migratetype)
{
spin_lock(&zone->lock);
- zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
+ zone->all_unreclaimable = 0;
zone->pages_scanned = 0;
__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
@@ -2270,7 +2270,7 @@ void show_free_areas(void)
K(zone_page_state(zone, NR_BOUNCE)),
K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
zone->pages_scanned,
- (zone_is_all_unreclaimable(zone) ? "yes" : "no")
+ (zone->all_unreclaimable ? "yes" : "no")
);
printk("lowmem_reserve[]:");
for (i = 0; i < MAX_NR_ZONES; i++)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 885207a..8057d36 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1694,8 +1694,7 @@ static void shrink_zones(int priority, struct zonelist *zonelist,
continue;
note_zone_scanning_priority(zone, priority);
- if (zone_is_all_unreclaimable(zone) &&
- priority != DEF_PRIORITY)
+ if (zone->all_unreclaimable && priority != DEF_PRIORITY)
continue; /* Let kswapd poll it */
sc->all_unreclaimable = 0;
} else {
@@ -2009,8 +2008,7 @@ loop_again:
if (!populated_zone(zone))
continue;
- if (zone_is_all_unreclaimable(zone) &&
- priority != DEF_PRIORITY)
+ if (zone->all_unreclaimable && priority != DEF_PRIORITY)
continue;
/*
@@ -2053,8 +2051,7 @@ loop_again:
if (!populated_zone(zone))
continue;
- if (zone_is_all_unreclaimable(zone) &&
- priority != DEF_PRIORITY)
+ if (zone->all_unreclaimable && priority != DEF_PRIORITY)
continue;
if (!zone_watermark_ok(zone, order,
@@ -2084,12 +2081,11 @@ loop_again:
lru_pages);
sc.nr_reclaimed += reclaim_state->reclaimed_slab;
total_scanned += sc.nr_scanned;
- if (zone_is_all_unreclaimable(zone))
+ if (zone->all_unreclaimable)
continue;
- if (nr_slab == 0 && zone->pages_scanned >=
- (zone_reclaimable_pages(zone) * 6))
- zone_set_flag(zone,
- ZONE_ALL_UNRECLAIMABLE);
+ if (nr_slab == 0 &&
+ zone->pages_scanned >= (zone_reclaimable_pages(zone) * 6))
+ zone->all_unreclaimable = 1;
/*
* If we've done a decent amount of scanning and
* the reclaim ratio is low, start doing writepage
@@ -2612,7 +2608,7 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
zone_page_state(zone, NR_SLAB_RECLAIMABLE) <= zone->min_slab_pages)
return ZONE_RECLAIM_FULL;
- if (zone_is_all_unreclaimable(zone))
+ if (zone->all_unreclaimable)
return ZONE_RECLAIM_FULL;
/*
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 6051fba..8175c64 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -761,7 +761,7 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
"\n prev_priority: %i"
"\n start_pfn: %lu"
"\n inactive_ratio: %u",
- zone_is_all_unreclaimable(zone),
+ zone->all_unreclaimable,
zone->prev_priority,
zone->zone_start_pfn,
zone->inactive_ratio);
--
1.6.5.2
--
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