138 lines
3.4 KiB
C
138 lines
3.4 KiB
C
/*
|
|
* linux/mm/page_isolation.c
|
|
*/
|
|
|
|
#include <linux/mm.h>
|
|
#include <linux/page-isolation.h>
|
|
#include <linux/pageblock-flags.h>
|
|
#include "internal.h"
|
|
|
|
static inline struct page *
|
|
__first_valid_page(unsigned long pfn, unsigned long nr_pages)
|
|
{
|
|
int i;
|
|
for (i = 0; i < nr_pages; i++)
|
|
if (pfn_valid_within(pfn + i))
|
|
break;
|
|
if (unlikely(i == nr_pages))
|
|
return NULL;
|
|
return pfn_to_page(pfn + i);
|
|
}
|
|
|
|
/*
|
|
* start_isolate_page_range() -- make page-allocation-type of range of pages
|
|
* to be MIGRATE_ISOLATE.
|
|
* @start_pfn: The lower PFN of the range to be isolated.
|
|
* @end_pfn: The upper PFN of the range to be isolated.
|
|
*
|
|
* Making page-allocation-type to be MIGRATE_ISOLATE means free pages in
|
|
* the range will never be allocated. Any free pages and pages freed in the
|
|
* future will not be allocated again.
|
|
*
|
|
* start_pfn/end_pfn must be aligned to pageblock_order.
|
|
* Returns 0 on success and -EBUSY if any part of range cannot be isolated.
|
|
*/
|
|
int
|
|
start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn)
|
|
{
|
|
unsigned long pfn;
|
|
unsigned long undo_pfn;
|
|
struct page *page;
|
|
|
|
BUG_ON((start_pfn) & (pageblock_nr_pages - 1));
|
|
BUG_ON((end_pfn) & (pageblock_nr_pages - 1));
|
|
|
|
for (pfn = start_pfn;
|
|
pfn < end_pfn;
|
|
pfn += pageblock_nr_pages) {
|
|
page = __first_valid_page(pfn, pageblock_nr_pages);
|
|
if (page && set_migratetype_isolate(page)) {
|
|
undo_pfn = pfn;
|
|
goto undo;
|
|
}
|
|
}
|
|
return 0;
|
|
undo:
|
|
for (pfn = start_pfn;
|
|
pfn < undo_pfn;
|
|
pfn += pageblock_nr_pages)
|
|
unset_migratetype_isolate(pfn_to_page(pfn));
|
|
|
|
return -EBUSY;
|
|
}
|
|
|
|
/*
|
|
* Make isolated pages available again.
|
|
*/
|
|
int
|
|
undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn)
|
|
{
|
|
unsigned long pfn;
|
|
struct page *page;
|
|
BUG_ON((start_pfn) & (pageblock_nr_pages - 1));
|
|
BUG_ON((end_pfn) & (pageblock_nr_pages - 1));
|
|
for (pfn = start_pfn;
|
|
pfn < end_pfn;
|
|
pfn += pageblock_nr_pages) {
|
|
page = __first_valid_page(pfn, pageblock_nr_pages);
|
|
if (!page || get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
|
|
continue;
|
|
unset_migratetype_isolate(page);
|
|
}
|
|
return 0;
|
|
}
|
|
/*
|
|
* Test all pages in the range is free(means isolated) or not.
|
|
* all pages in [start_pfn...end_pfn) must be in the same zone.
|
|
* zone->lock must be held before call this.
|
|
*
|
|
* Returns 0 if all pages in the range is isolated.
|
|
*/
|
|
static int
|
|
__test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn)
|
|
{
|
|
struct page *page;
|
|
|
|
while (pfn < end_pfn) {
|
|
if (!pfn_valid_within(pfn)) {
|
|
pfn++;
|
|
continue;
|
|
}
|
|
page = pfn_to_page(pfn);
|
|
if (PageBuddy(page))
|
|
pfn += 1 << page_order(page);
|
|
else if (page_count(page) == 0 &&
|
|
page_private(page) == MIGRATE_ISOLATE)
|
|
pfn += 1;
|
|
else
|
|
break;
|
|
}
|
|
if (pfn < end_pfn)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
|
|
{
|
|
unsigned long pfn;
|
|
struct page *page;
|
|
|
|
pfn = start_pfn;
|
|
/*
|
|
* Note: pageblock_nr_page != MAX_ORDER. Then, chunks of free page
|
|
* is not aligned to pageblock_nr_pages.
|
|
* Then we just check pagetype fist.
|
|
*/
|
|
for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
|
|
page = __first_valid_page(pfn, pageblock_nr_pages);
|
|
if (page && get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
|
|
break;
|
|
}
|
|
if (pfn < end_pfn)
|
|
return -EBUSY;
|
|
/* Check all pages are free or Marked as ISOLATED */
|
|
if (__test_page_isolated_in_pageblock(start_pfn, end_pfn))
|
|
return 0;
|
|
return -EBUSY;
|
|
}
|