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@suse.cz: fix crash in get_pfnblock_flags_mask() from isolate_freepages():]
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Rik van Riel <riel@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@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:
Vlastimil Babka 2016-05-19 17:11:48 -07:00 committed by Linus Torvalds
parent e4c5800a39
commit 06b6640a39

View File

@ -42,6 +42,11 @@ static inline void count_compact_events(enum vm_event_item item, long delta)
#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(struct zone *zone)
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_control *cc,
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_control *cc,
* 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 compact_control *cc, unsigned long start_pfn,
/* 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 compact_control *cc)
* 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_migratepages(struct zone *zone,
* 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 *zone, struct compact_control *cc)
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()