From: Vlastimil Babka <vbabka@xxxxxxx>
Subject: mm, compaction: wrap calculating first and last pfn of pageblock
Compaction code has accumulated numerous instances of manual calculations
of the first (inclusive) and last (exclusive) pfn of a pageblock (or a
smaller block of given order), given a pfn within the pageblock. Wrap
these calculations by introducing pageblock_start_pfn(pfn) and
pageblock_end_pfn(pfn) macros.
[vbabka@xxxxxxx: fix crash in get_pfnblock_flags_mask() from isolate_freepages():]
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/compaction.c | 33 +++++++++++++++++++--------------
1 file changed, 19 insertions(+), 14 deletions(-)
diff -puN mm/compaction.c~mm-compaction-wrap-calculating-first-and-last-pfn-of-pageblock mm/compaction.c
--- a/mm/compaction.c~mm-compaction-wrap-calculating-first-and-last-pfn-of-pageblock
+++ a/mm/compaction.c
@@ -42,6 +42,11 @@ static inline void count_compact_events(
#define CREATE_TRACE_POINTS
#include <trace/events/compaction.h>
+#define block_start_pfn(pfn, order) round_down(pfn, 1UL << (order))
+#define block_end_pfn(pfn, order) ALIGN((pfn) + 1, 1UL << (order))
+#define pageblock_start_pfn(pfn) block_start_pfn(pfn, pageblock_order)
+#define pageblock_end_pfn(pfn) block_end_pfn(pfn, pageblock_order)
+
static unsigned long release_freepages(struct list_head *freelist)
{
struct page *page, *next;
@@ -161,7 +166,7 @@ static void reset_cached_positions(struc
zone->compact_cached_migrate_pfn[0] = zone->zone_start_pfn;
zone->compact_cached_migrate_pfn[1] = zone->zone_start_pfn;
zone->compact_cached_free_pfn =
- round_down(zone_end_pfn(zone) - 1, pageblock_nr_pages);
+ pageblock_start_pfn(zone_end_pfn(zone) - 1);
}
/*
@@ -519,10 +524,10 @@ isolate_freepages_range(struct compact_c
LIST_HEAD(freelist);
pfn = start_pfn;
- block_start_pfn = pfn & ~(pageblock_nr_pages - 1);
+ block_start_pfn = pageblock_start_pfn(pfn);
if (block_start_pfn < cc->zone->zone_start_pfn)
block_start_pfn = cc->zone->zone_start_pfn;
- block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages);
+ block_end_pfn = pageblock_end_pfn(pfn);
for (; pfn < end_pfn; pfn += isolated,
block_start_pfn = block_end_pfn,
@@ -538,8 +543,8 @@ isolate_freepages_range(struct compact_c
* scanning range to right one.
*/
if (pfn >= block_end_pfn) {
- block_start_pfn = pfn & ~(pageblock_nr_pages - 1);
- block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages);
+ block_start_pfn = pageblock_start_pfn(pfn);
+ block_end_pfn = pageblock_end_pfn(pfn);
block_end_pfn = min(block_end_pfn, end_pfn);
}
@@ -834,10 +839,10 @@ isolate_migratepages_range(struct compac
/* Scan block by block. First and last block may be incomplete */
pfn = start_pfn;
- block_start_pfn = pfn & ~(pageblock_nr_pages - 1);
+ block_start_pfn = pageblock_start_pfn(pfn);
if (block_start_pfn < cc->zone->zone_start_pfn)
block_start_pfn = cc->zone->zone_start_pfn;
- block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages);
+ block_end_pfn = pageblock_end_pfn(pfn);
for (; pfn < end_pfn; pfn = block_end_pfn,
block_start_pfn = block_end_pfn,
@@ -924,10 +929,10 @@ static void isolate_freepages(struct com
* is using.
*/
isolate_start_pfn = cc->free_pfn;
- block_start_pfn = cc->free_pfn & ~(pageblock_nr_pages-1);
+ block_start_pfn = pageblock_start_pfn(cc->free_pfn);
block_end_pfn = min(block_start_pfn + pageblock_nr_pages,
zone_end_pfn(zone));
- low_pfn = ALIGN(cc->migrate_pfn + 1, pageblock_nr_pages);
+ low_pfn = pageblock_end_pfn(cc->migrate_pfn);
/*
* Isolate free pages until enough are available to migrate the
@@ -1081,12 +1086,12 @@ static isolate_migrate_t isolate_migrate
* initialized by compact_zone()
*/
low_pfn = cc->migrate_pfn;
- block_start_pfn = cc->migrate_pfn & ~(pageblock_nr_pages - 1);
+ block_start_pfn = pageblock_start_pfn(low_pfn);
if (block_start_pfn < zone->zone_start_pfn)
block_start_pfn = zone->zone_start_pfn;
/* Only scan within a pageblock boundary */
- block_end_pfn = ALIGN(low_pfn + 1, pageblock_nr_pages);
+ block_end_pfn = pageblock_end_pfn(low_pfn);
/*
* Iterate over whole pageblocks until we find the first suitable.
@@ -1343,7 +1348,7 @@ static int compact_zone(struct zone *zon
cc->migrate_pfn = zone->compact_cached_migrate_pfn[sync];
cc->free_pfn = zone->compact_cached_free_pfn;
if (cc->free_pfn < start_pfn || cc->free_pfn >= end_pfn) {
- cc->free_pfn = round_down(end_pfn - 1, pageblock_nr_pages);
+ cc->free_pfn = pageblock_start_pfn(end_pfn - 1);
zone->compact_cached_free_pfn = cc->free_pfn;
}
if (cc->migrate_pfn < start_pfn || cc->migrate_pfn >= end_pfn) {
@@ -1411,7 +1416,7 @@ check_drain:
if (cc->order > 0 && cc->last_migrated_pfn) {
int cpu;
unsigned long current_block_start =
- cc->migrate_pfn & ~((1UL << cc->order) - 1);
+ block_start_pfn(cc->migrate_pfn, cc->order);
if (cc->last_migrated_pfn < current_block_start) {
cpu = get_cpu();
@@ -1436,7 +1441,7 @@ out:
cc->nr_freepages = 0;
VM_BUG_ON(free_pfn == 0);
/* The cached pfn is always the first in a pageblock */
- free_pfn &= ~(pageblock_nr_pages-1);
+ free_pfn = pageblock_start_pfn(free_pfn);
/*
* Only go back, not forward. The cached pfn might have been
* already reset to zone end in compact_finished()
_
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
