Release 4.16 mm/page_isolation.c
// SPDX-License-Identifier: GPL-2.0
/*
* linux/mm/page_isolation.c
*/
#include <linux/mm.h>
#include <linux/page-isolation.h>
#include <linux/pageblock-flags.h>
#include <linux/memory.h>
#include <linux/hugetlb.h>
#include <linux/page_owner.h>
#include <linux/migrate.h>
#include "internal.h"
#define CREATE_TRACE_POINTS
#include <trace/events/page_isolation.h>
static int set_migratetype_isolate(struct page *page, int migratetype,
bool skip_hwpoisoned_pages)
{
struct zone *zone;
unsigned long flags, pfn;
struct memory_isolate_notify arg;
int notifier_ret;
int ret = -EBUSY;
zone = page_zone(page);
spin_lock_irqsave(&zone->lock, flags);
pfn = page_to_pfn(page);
arg.start_pfn = pfn;
arg.nr_pages = pageblock_nr_pages;
arg.pages_found = 0;
/*
* It may be possible to isolate a pageblock even if the
* migratetype is not MIGRATE_MOVABLE. The memory isolation
* notifier chain is used by balloon drivers to return the
* number of pages in a range that are held by the balloon
* driver to shrink memory. If all the pages are accounted for
* by balloons, are free, or on the LRU, isolation can continue.
* Later, for example, when memory hotplug notifier runs, these
* pages reported as "can be isolated" should be isolated(freed)
* by the balloon driver through the memory notifier chain.
*/
notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg);
notifier_ret = notifier_to_errno(notifier_ret);
if (notifier_ret)
goto out;
/*
* FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.
* We just check MOVABLE pages.
*/
if (!has_unmovable_pages(zone, page, arg.pages_found, migratetype,
skip_hwpoisoned_pages))
ret = 0;
/*
* immobile means "not-on-lru" pages. If immobile is larger than
* removable-by-driver pages reported by notifier, we'll fail.
*/
out:
if (!ret) {
unsigned long nr_pages;
int mt = get_pageblock_migratetype(page);
set_pageblock_migratetype(page, MIGRATE_ISOLATE);
zone->nr_isolate_pageblock++;
nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE,
NULL);
__mod_zone_freepage_state(zone, -nr_pages, mt);
}
spin_unlock_irqrestore(&zone->lock, flags);
if (!ret)
drain_all_pages(zone);
return ret;
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
MinChan Kim | 162 | 76.78% | 1 | 8.33% |
Bartlomiej Zolnierkiewicz | 25 | 11.85% | 3 | 25.00% |
Michal Hocko | 7 | 3.32% | 1 | 8.33% |
Vlastimil Babka | 5 | 2.37% | 3 | 25.00% |
Wen Congyang | 5 | 2.37% | 1 | 8.33% |
JoonSoo Kim | 5 | 2.37% | 1 | 8.33% |
Yisheng Xie | 1 | 0.47% | 1 | 8.33% |
Naoya Horiguchi | 1 | 0.47% | 1 | 8.33% |
Total | 211 | 100.00% | 12 | 100.00% |
static void unset_migratetype_isolate(struct page *page, unsigned migratetype)
{
struct zone *zone;
unsigned long flags, nr_pages;
bool isolated_page = false;
unsigned int order;
unsigned long pfn, buddy_pfn;
struct page *buddy;
zone = page_zone(page);
spin_lock_irqsave(&zone->lock, flags);
if (!is_migrate_isolate_page(page))
goto out;
/*
* Because freepage with more than pageblock_order on isolated
* pageblock is restricted to merge due to freepage counting problem,
* it is possible that there is free buddy page.
* move_freepages_block() doesn't care of merge so we need other
* approach in order to merge them. Isolation and free will make
* these pages to be merged.
*/
if (PageBuddy(page)) {
order = page_order(page);
if (order >= pageblock_order) {
pfn = page_to_pfn(page);
buddy_pfn = __find_buddy_pfn(pfn, order);
buddy = page + (buddy_pfn - pfn);
if (pfn_valid_within(buddy_pfn) &&
!is_migrate_isolate_page(buddy)) {
__isolate_free_page(page, order);
isolated_page = true;
}
}
}
/*
* If we isolate freepage with more than pageblock_order, there
* should be no freepage in the range, so we could avoid costly
* pageblock scanning for freepage moving.
*/
if (!isolated_page) {
nr_pages = move_freepages_block(zone, page, migratetype, NULL);
__mod_zone_freepage_state(zone, nr_pages, migratetype);
}
set_pageblock_migratetype(page, migratetype);
zone->nr_isolate_pageblock--;
out:
spin_unlock_irqrestore(&zone->lock, flags);
if (isolated_page) {
post_alloc_hook(page, order, __GFP_MOVABLE);
__free_pages(page, order);
}
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
JoonSoo Kim | 119 | 52.65% | 5 | 31.25% |
MinChan Kim | 75 | 33.19% | 2 | 12.50% |
Bartlomiej Zolnierkiewicz | 14 | 6.19% | 3 | 18.75% |
Vlastimil Babka | 11 | 4.87% | 3 | 18.75% |
Hui Zhu | 4 | 1.77% | 1 | 6.25% |
Xishi Qiu | 2 | 0.88% | 1 | 6.25% |
Naoya Horiguchi | 1 | 0.44% | 1 | 6.25% |
Total | 226 | 100.00% | 16 | 100.00% |
static inline struct page *
__first_valid_page(unsigned long pfn, unsigned long nr_pages)
{
int i;
for (i = 0; i < nr_pages; i++) {
struct page *page;
if (!pfn_valid_within(pfn + i))
continue;
page = pfn_to_online_page(pfn + i);
if (!page)
continue;
return page;
}
return NULL;
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
Kamezawa Hiroyuki | 50 | 69.44% | 1 | 50.00% |
Michal Hocko | 22 | 30.56% | 1 | 50.00% |
Total | 72 | 100.00% | 2 | 100.00% |
/*
* 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.
* @migratetype: migrate type to set in error recovery.
*
* 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 migratetype, bool skip_hwpoisoned_pages)
{
unsigned long pfn;
unsigned long undo_pfn;
struct page *page;
BUG_ON(!IS_ALIGNED(start_pfn, pageblock_nr_pages));
BUG_ON(!IS_ALIGNED(end_pfn, pageblock_nr_pages));
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, migratetype, skip_hwpoisoned_pages)) {
undo_pfn = pfn;
goto undo;
}
}
return 0;
undo:
for (pfn = start_pfn;
pfn < undo_pfn;
pfn += pageblock_nr_pages) {
struct page *page = pfn_to_online_page(pfn);
if (!page)
continue;
unset_migratetype_isolate(page, migratetype);
}
return -EBUSY;
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
Kamezawa Hiroyuki | 109 | 73.15% | 2 | 28.57% |
Michal Hocko | 20 | 13.42% | 2 | 28.57% |
Naoya Horiguchi | 10 | 6.71% | 1 | 14.29% |
Michal Nazarewicz | 5 | 3.36% | 1 | 14.29% |
Wen Congyang | 5 | 3.36% | 1 | 14.29% |
Total | 149 | 100.00% | 7 | 100.00% |
/*
* Make isolated pages available again.
*/
int undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
unsigned migratetype)
{
unsigned long pfn;
struct page *page;
BUG_ON(!IS_ALIGNED(start_pfn, pageblock_nr_pages));
BUG_ON(!IS_ALIGNED(end_pfn, pageblock_nr_pages));
for (pfn = start_pfn;
pfn < end_pfn;
pfn += pageblock_nr_pages) {
page = __first_valid_page(pfn, pageblock_nr_pages);
if (!page || !is_migrate_isolate_page(page))
continue;
unset_migratetype_isolate(page, migratetype);
}
return 0;
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
Kamezawa Hiroyuki | 77 | 81.91% | 1 | 25.00% |
Wang Xiaoqiang | 10 | 10.64% | 1 | 25.00% |
Michal Nazarewicz | 5 | 5.32% | 1 | 25.00% |
Xishi Qiu | 2 | 2.13% | 1 | 25.00% |
Total | 94 | 100.00% | 4 | 100.00% |
/*
* 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 the last tested pfn.
*/
static unsigned long
__test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn,
bool skip_hwpoisoned_pages)
{
struct page *page;
while (pfn < end_pfn) {
if (!pfn_valid_within(pfn)) {
pfn++;
continue;
}
page = pfn_to_page(pfn);
if (PageBuddy(page))
/*
* If the page is on a free list, it has to be on
* the correct MIGRATE_ISOLATE freelist. There is no
* simple way to verify that as VM_BUG_ON(), though.
*/
pfn += 1 << page_order(page);
else if (skip_hwpoisoned_pages && PageHWPoison(page))
/* A HWPoisoned page cannot be also PageBuddy */
pfn++;
else
break;
}
return pfn;
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
Kamezawa Hiroyuki | 67 | 76.14% | 1 | 25.00% |
Wen Congyang | 16 | 18.18% | 1 | 25.00% |
JoonSoo Kim | 3 | 3.41% | 1 | 25.00% |
Vlastimil Babka | 2 | 2.27% | 1 | 25.00% |
Total | 88 | 100.00% | 4 | 100.00% |
/* Caller should ensure that requested range is in a single zone */
int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
bool skip_hwpoisoned_pages)
{
unsigned long pfn, flags;
struct page *page;
struct zone *zone;
/*
* Note: pageblock_nr_pages != MAX_ORDER. Then, chunks of free pages
* are not aligned to pageblock_nr_pages.
* Then we just check migratetype first.
*/
for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
page = __first_valid_page(pfn, pageblock_nr_pages);
if (page && !is_migrate_isolate_page(page))
break;
}
page = __first_valid_page(start_pfn, end_pfn - start_pfn);
if ((pfn < end_pfn) || !page)
return -EBUSY;
/* Check all pages are free or marked as ISOLATED */
zone = page_zone(page);
spin_lock_irqsave(&zone->lock, flags);
pfn = __test_page_isolated_in_pageblock(start_pfn, end_pfn,
skip_hwpoisoned_pages);
spin_unlock_irqrestore(&zone->lock, flags);
trace_test_pages_isolated(start_pfn, end_pfn, pfn);
return pfn < end_pfn ? -EBUSY : 0;
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
Kamezawa Hiroyuki | 76 | 49.67% | 1 | 12.50% |
Gerald Schaefer | 53 | 34.64% | 2 | 25.00% |
JoonSoo Kim | 15 | 9.80% | 2 | 25.00% |
Wen Congyang | 5 | 3.27% | 1 | 12.50% |
Tang Chen | 2 | 1.31% | 1 | 12.50% |
Xishi Qiu | 2 | 1.31% | 1 | 12.50% |
Total | 153 | 100.00% | 8 | 100.00% |
struct page *alloc_migrate_target(struct page *page, unsigned long private,
int **resultp)
{
return new_page_nodemask(page, numa_node_id(), &node_states[N_MEMORY]);
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
MinChan Kim | 23 | 63.89% | 1 | 25.00% |
Michal Hocko | 8 | 22.22% | 1 | 25.00% |
Naoya Horiguchi | 4 | 11.11% | 1 | 25.00% |
Andrew Morton | 1 | 2.78% | 1 | 25.00% |
Total | 36 | 100.00% | 4 | 100.00% |
Overall Contributors
Person | Tokens | Prop | Commits | CommitProp |
Kamezawa Hiroyuki | 393 | 36.90% | 2 | 5.00% |
MinChan Kim | 263 | 24.69% | 3 | 7.50% |
JoonSoo Kim | 152 | 14.27% | 8 | 20.00% |
Michal Hocko | 60 | 5.63% | 3 | 7.50% |
Gerald Schaefer | 53 | 4.98% | 2 | 5.00% |
Bartlomiej Zolnierkiewicz | 39 | 3.66% | 3 | 7.50% |
Wen Congyang | 31 | 2.91% | 1 | 2.50% |
Naoya Horiguchi | 19 | 1.78% | 3 | 7.50% |
Vlastimil Babka | 18 | 1.69% | 6 | 15.00% |
Michal Nazarewicz | 11 | 1.03% | 1 | 2.50% |
Wang Xiaoqiang | 10 | 0.94% | 1 | 2.50% |
Xishi Qiu | 6 | 0.56% | 1 | 2.50% |
Hui Zhu | 4 | 0.38% | 1 | 2.50% |
Tang Chen | 2 | 0.19% | 1 | 2.50% |
Yisheng Xie | 1 | 0.09% | 1 | 2.50% |
Andrew Morton | 1 | 0.09% | 1 | 2.50% |
Neil Zhang | 1 | 0.09% | 1 | 2.50% |
Greg Kroah-Hartman | 1 | 0.09% | 1 | 2.50% |
Total | 1065 | 100.00% | 40 | 100.00% |
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