The patch titled
mm: restore zone->all_unreclaimable to independence word
has been added to the -mm tree. Its filename is
mm-restore-zone-all_unreclaimable-to-independence-word.patch
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------------------------------------------------------
Subject: mm: restore zone->all_unreclaimable to independence word
From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
commit e815af95 ("change all_unreclaimable zone member to flags") changed
all_unreclaimable member to bit flag. But it had an 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@xxxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Wu Fengguang <fengguang.wu@xxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
Cc: Huang Shijie <shijie8@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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 -puN include/linux/mmzone.h~mm-restore-zone-all_unreclaimable-to-independence-word include/linux/mmzone.h
--- a/include/linux/mmzone.h~mm-restore-zone-all_unreclaimable-to-independence-word
+++ a/include/linux/mmzone.h
@@ -333,6 +333,7 @@ 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];
@@ -417,7 +418,6 @@ 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;
@@ -437,11 +437,6 @@ static inline void zone_clear_flag(struc
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 -puN mm/page_alloc.c~mm-restore-zone-all_unreclaimable-to-independence-word mm/page_alloc.c
--- a/mm/page_alloc.c~mm-restore-zone-all_unreclaimable-to-independence-word
+++ a/mm/page_alloc.c
@@ -549,7 +549,7 @@ static void free_pcppages_bulk(struct zo
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);
@@ -586,7 +586,7 @@ static void free_one_page(struct zone *z
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);
@@ -2280,7 +2280,7 @@ 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 -puN mm/vmscan.c~mm-restore-zone-all_unreclaimable-to-independence-word mm/vmscan.c
--- a/mm/vmscan.c~mm-restore-zone-all_unreclaimable-to-independence-word
+++ a/mm/vmscan.c
@@ -1721,8 +1721,7 @@ static void shrink_zones(int priority, s
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 {
@@ -2039,8 +2038,7 @@ loop_again:
if (!populated_zone(zone))
continue;
- if (zone_is_all_unreclaimable(zone) &&
- priority != DEF_PRIORITY)
+ if (zone->all_unreclaimable && priority != DEF_PRIORITY)
continue;
/*
@@ -2083,8 +2081,7 @@ loop_again:
if (!populated_zone(zone))
continue;
- if (zone_is_all_unreclaimable(zone) &&
- priority != DEF_PRIORITY)
+ if (zone->all_unreclaimable && priority != DEF_PRIORITY)
continue;
temp_priority[i] = priority;
@@ -2111,12 +2108,11 @@ 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
@@ -2646,7 +2642,7 @@ int zone_reclaim(struct zone *zone, gfp_
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 -puN mm/vmstat.c~mm-restore-zone-all_unreclaimable-to-independence-word mm/vmstat.c
--- a/mm/vmstat.c~mm-restore-zone-all_unreclaimable-to-independence-word
+++ a/mm/vmstat.c
@@ -765,7 +765,7 @@ static void zoneinfo_show_print(struct s
"\n start_pfn: %lu"
"\n inactive_ratio: %u"
"\n anon_scan_ratio: %lu",
- zone_is_all_unreclaimable(zone),
+ zone->all_unreclaimable,
zone->prev_priority,
zone->zone_start_pfn,
zone->inactive_ratio,
_
Patches currently in -mm which might be from kosaki.motohiro@xxxxxxxxxxxxxx are
linux-next.patch
page-allocator-fix-update-nr_free_pages-only-as-necessary.patch
mm-page_alloc-fix-the-range-check-for-backward-merging.patch
vmscan-kswapd-dont-retry-balance_pgdat-if-all-zones-are-unreclaimable.patch
mm-introduce-dump_page-and-print-symbolic-flag-names.patch
page-allocator-reduce-fragmentation-in-buddy-allocator-by-adding-buddies-that-are-merging-to-the-tail-of-the-free-lists.patch
mlock_vma_pages_range-never-return-negative-value.patch
mlock_vma_pages_range-only-return-success-or-failure.patch
vmscan-check-high-watermark-after-shrink-zone.patch
vmscan-check-high-watermark-after-shrink-zone-fix.patch
vmscan-get_scan_ratio-cleanup.patch
vmstat-add-anon_scan_ratio-field-to-zoneinfo.patch
memcg-add-anon_scan_ratio-to-memorystat-file.patch
mm-lockdep-annotate-reclaim-context-to-zone-reclaim-too.patch
mm-page_allocc-remove-duplicate-call-to-trace_mm_page_free_direct.patch
mm-page_allocc-adjust-a-call-site-to-trace_mm_page_free_direct.patch
mm-remove-function-free_hot_page.patch
mm-restore-zone-all_unreclaimable-to-independence-word.patch
prctl-add-pr_set_proctitle_area-option-for-prctl.patch
mm-pass-mm-flags-as-a-coredump-parameter-for-consistency.patch
fs-symlink-write_begin-allocation-context-fix-reiser4-fix.patch
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