mm: clean up __count_immobile_pages()

The __count_immobile_pages() naming is rather awkward.  Choose a more
clear name and add a comment.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Minchan Kim 2012-07-31 16:43:01 -07:00 committed by Linus Torvalds
parent 97d255c816
commit 80934513b2
1 changed files with 18 additions and 16 deletions

View File

@ -5471,26 +5471,28 @@ void set_pageblock_flags_group(struct page *page, unsigned long flags,
}
/*
* This is designed as sub function...plz see page_isolation.c also.
* set/clear page block's type to be ISOLATE.
* page allocater never alloc memory from ISOLATE block.
* This function checks whether pageblock includes unmovable pages or not.
* If @count is not zero, it is okay to include less @count unmovable pages
*
* PageLRU check wihtout isolation or lru_lock could race so that
* MIGRATE_MOVABLE block might include unmovable pages. It means you can't
* expect this function should be exact.
*/
static int
__count_immobile_pages(struct zone *zone, struct page *page, int count)
static bool
__has_unmovable_pages(struct zone *zone, struct page *page, int count)
{
unsigned long pfn, iter, found;
int mt;
/*
* For avoiding noise data, lru_add_drain_all() should be called
* If ZONE_MOVABLE, the zone never contains immobile pages
* If ZONE_MOVABLE, the zone never contains unmovable pages
*/
if (zone_idx(zone) == ZONE_MOVABLE)
return true;
return false;
mt = get_pageblock_migratetype(page);
if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
return true;
return false;
pfn = page_to_pfn(page);
for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
@ -5528,9 +5530,9 @@ __count_immobile_pages(struct zone *zone, struct page *page, int count)
* page at boot.
*/
if (found > count)
return false;
}
return true;
}
return false;
}
bool is_pageblock_removable_nolock(struct page *page)
@ -5554,7 +5556,7 @@ bool is_pageblock_removable_nolock(struct page *page)
zone->zone_start_pfn + zone->spanned_pages <= pfn)
return false;
return __count_immobile_pages(zone, page, 0);
return !__has_unmovable_pages(zone, page, 0);
}
int set_migratetype_isolate(struct page *page)
@ -5593,12 +5595,12 @@ int set_migratetype_isolate(struct page *page)
* FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.
* We just check MOVABLE pages.
*/
if (__count_immobile_pages(zone, page, arg.pages_found))
if (!__has_unmovable_pages(zone, page, arg.pages_found))
ret = 0;
/*
* immobile means "not-on-lru" paes. If immobile is larger than
* removable-by-driver pages reported by notifier, we'll fail.
* Unmovable means "not-on-lru" pages. If Unmovable pages are
* larger than removable-by-driver pages reported by notifier,
* we'll fail.
*/
out: