The patch titled
introduce HIGH_ORDER delineating easily reclaimable orders
has been added to the -mm tree. Its filename is
introduce-high_order-delineating-easily-reclaimable-orders.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: introduce HIGH_ORDER delineating easily reclaimable orders
From: Andy Whitcroft <apw@xxxxxxxxxxxx>
The memory allocator treats lower order (order <= 3) and higher order
(order >= 4) allocations in slightly different ways. As lower orders are
much more likely to be available and also more likely to be simply
reclaimed it is deemed reasonable to wait longer for those. Lumpy reclaim
also changes behaviour at this same boundary, more agressivly targetting
pages in reclaim at higher order.
This patch removes all these magical numbers and replaces with
with a constant HIGH_ORDER.
Signed-off-by: Andy Whitcroft <apw@xxxxxxxxxxxx>
Acked-by: Mel Gorman <mel@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mmzone.h | 7 +++++++
mm/page_alloc.c | 2 +-
mm/vmscan.c | 11 ++++++-----
3 files changed, 14 insertions(+), 6 deletions(-)
diff -puN include/linux/mmzone.h~introduce-high_order-delineating-easily-reclaimable-orders include/linux/mmzone.h
--- a/include/linux/mmzone.h~introduce-high_order-delineating-easily-reclaimable-orders
+++ a/include/linux/mmzone.h
@@ -25,6 +25,13 @@
#endif
#define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1))
+/*
+ * The boundary between small and large allocations. That is between
+ * allocation orders which should colesce naturally under reasonable
+ * reclaim pressure and those which will not.
+ */
+#define HIGH_ORDER 3
+
#ifdef CONFIG_PAGE_GROUP_BY_MOBILITY
#define MIGRATE_UNMOVABLE 0
#define MIGRATE_RECLAIMABLE 1
diff -puN mm/page_alloc.c~introduce-high_order-delineating-easily-reclaimable-orders mm/page_alloc.c
--- a/mm/page_alloc.c~introduce-high_order-delineating-easily-reclaimable-orders
+++ a/mm/page_alloc.c
@@ -1677,7 +1677,7 @@ nofail_alloc:
*/
do_retry = 0;
if (!(gfp_mask & __GFP_NORETRY)) {
- if ((order <= 3) || (gfp_mask & __GFP_REPEAT))
+ if ((order <= HIGH_ORDER) || (gfp_mask & __GFP_REPEAT))
do_retry = 1;
if (gfp_mask & __GFP_NOFAIL)
do_retry = 1;
diff -puN mm/vmscan.c~introduce-high_order-delineating-easily-reclaimable-orders mm/vmscan.c
--- a/mm/vmscan.c~introduce-high_order-delineating-easily-reclaimable-orders
+++ a/mm/vmscan.c
@@ -487,7 +487,8 @@ static unsigned long shrink_page_list(st
referenced = page_referenced(page, 1);
/* In active use or really unfreeable? Activate it. */
- if (sc->order <= 3 && referenced && page_mapping_inuse(page))
+ if (sc->order <= HIGH_ORDER &&
+ referenced && page_mapping_inuse(page))
goto activate_locked;
#ifdef CONFIG_SWAP
@@ -520,7 +521,7 @@ static unsigned long shrink_page_list(st
}
if (PageDirty(page)) {
- if (sc->order <= 3 && referenced)
+ if (sc->order <= HIGH_ORDER && referenced)
goto keep_locked;
if (!may_enter_fs)
goto keep_locked;
@@ -790,9 +791,9 @@ static unsigned long shrink_inactive_lis
unsigned long nr_active;
nr_taken = isolate_lru_pages(sc->swap_cluster_max,
- &zone->inactive_list,
- &page_list, &nr_scan, sc->order,
- (sc->order > 3)? ISOLATE_BOTH : 0);
+ &zone->inactive_list,
+ &page_list, &nr_scan, sc->order,
+ (sc->order > HIGH_ORDER)? ISOLATE_BOTH : 0);
nr_active = deactivate_pages(&page_list);
__mod_zone_page_state(zone, NR_ACTIVE, -nr_active);
_
Patches currently in -mm which might be from apw@xxxxxxxxxxxx are
pci-device-ensure-sysdata-initialised-v2.patch
add-a-bitmap-that-is-used-to-track-flags-affecting-a-block-of-pages-fix.patch
add-a-configure-option-to-group-pages-by-mobility-speedup.patch
move-free-pages-between-lists-on-steal-fix.patch
do-not-group-pages-by-mobility-type-on-low-memory-systems.patch
fix-corruption-of-memmap-on-ia64-sparsemem-when-mem_section-is-not-a-power-of-2.patch
lumpy-reclaim-v4.patch
lumpy-back-out-removal-of-active-check-in-isolate_lru_pages.patch
lumpy-only-count-taken-pages-as-scanned.patch
kswapd-use-reclaim-order-in-background-reclaim.patch
lumpy-increase-pressure-at-the-end-of-the-inactive-list.patch
introduce-high_order-delineating-easily-reclaimable-orders.patch
add-pfn_valid_within-helper-for-sub-max_order-hole-detection.patch
anti-fragmentation-switch-over-to-pfn_valid_within.patch
lumpy-move-to-using-pfn_valid_within.patch
bias-the-location-of-pages-freed-for-min_free_kbytes-in-the-same-max_order_nr_pages-blocks.patch
bias-the-location-of-pages-freed-for-min_free_kbytes-in-the-same-max_order_nr_pages-blocks-tidy.patch
bias-the-location-of-pages-freed-for-min_free_kbytes-in-the-same-max_order_nr_pages-blocks-tidy-fix.patch
remove-page_group_by_mobility.patch
dont-group-high-order-atomic-allocations.patch
slab-numa-kmem_cache-diet.patch
sched-implement-staircase-deadline-cpu-scheduler-misc-fixes.patch
-
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