alistair23-linux/include/linux/page-isolation.h
Michal Hocko 4da2ce250f mm: distinguish CMA and MOVABLE isolation in has_unmovable_pages()
Joonsoo has noticed that "mm: drop migrate type checks from
has_unmovable_pages" would break CMA allocator because it relies on
has_unmovable_pages returning false even for CMA pageblocks which in
fact don't have to be movable:

 alloc_contig_range
   start_isolate_page_range
     set_migratetype_isolate
       has_unmovable_pages

This is a result of the code sharing between CMA and memory hotplug
while each one has a different idea of what has_unmovable_pages should
return.  This is unfortunate but fixing it properly would require a lot
of code duplication.

Fix the issue by introducing the requested migrate type argument and
special case MIGRATE_CMA case where CMA page blocks are handled
properly.  This will work for memory hotplug because it requires
MIGRATE_MOVABLE.

Link: http://lkml.kernel.org/r/20171019122118.y6cndierwl2vnguj@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Tested-by: Ran Wang <ran.wang_1@nxp.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-15 18:21:02 -08:00

70 lines
1.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_PAGEISOLATION_H
#define __LINUX_PAGEISOLATION_H
#ifdef CONFIG_MEMORY_ISOLATION
static inline bool has_isolate_pageblock(struct zone *zone)
{
return zone->nr_isolate_pageblock;
}
static inline bool is_migrate_isolate_page(struct page *page)
{
return get_pageblock_migratetype(page) == MIGRATE_ISOLATE;
}
static inline bool is_migrate_isolate(int migratetype)
{
return migratetype == MIGRATE_ISOLATE;
}
#else
static inline bool has_isolate_pageblock(struct zone *zone)
{
return false;
}
static inline bool is_migrate_isolate_page(struct page *page)
{
return false;
}
static inline bool is_migrate_isolate(int migratetype)
{
return false;
}
#endif
bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
int migratetype, bool skip_hwpoisoned_pages);
void set_pageblock_migratetype(struct page *page, int migratetype);
int move_freepages_block(struct zone *zone, struct page *page,
int migratetype, int *num_movable);
/*
* Changes migrate type in [start_pfn, end_pfn) to be MIGRATE_ISOLATE.
* If specified range includes migrate types other than MOVABLE or CMA,
* this will fail with -EBUSY.
*
* For isolating all pages in the range finally, the caller have to
* free all pages in the range. test_page_isolated() can be used for
* test it.
*/
int
start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
unsigned migratetype, bool skip_hwpoisoned_pages);
/*
* Changes MIGRATE_ISOLATE to MIGRATE_MOVABLE.
* target range is [start_pfn, end_pfn)
*/
int
undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
unsigned migratetype);
/*
* Test all pages in [start_pfn, end_pfn) are isolated or not.
*/
int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
bool skip_hwpoisoned_pages);
struct page *alloc_migrate_target(struct page *page, unsigned long private,
int **resultp);
#endif