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mm: remove pfn_valid_within() and CONFIG_HOLES_IN_ZONE

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Patch series "mm: remove pfn_valid_within() and CONFIG_HOLES_IN_ZONE".

After recent updates to freeing unused parts of the memory map, no
architecture can have holes in the memory map within a pageblock.  This
makes pfn_valid_within() check and CONFIG_HOLES_IN_ZONE configuration
option redundant.

The first patch removes them both in a mechanical way and the second patch
simplifies memory_hotplug::test_pages_in_a_zone() that had
pfn_valid_within() surrounded by more logic than simple if.

This patch (of 2):

After recent changes in freeing of the unused parts of the memory map and
rework of pfn_valid() in arm and arm64 there are no architectures that can
have holes in the memory map within a pageblock and so nothing can enable
CONFIG_HOLES_IN_ZONE which guards non trivial implementation of
pfn_valid_within().

With that, pfn_valid_within() is always hardwired to 1 and can be
completely removed.

Remove calls to pfn_valid_within() and CONFIG_HOLES_IN_ZONE.

Link: https://lkml.kernel.org/r/20210713080035.7464-1-rppt@kernel.org
Link: https://lkml.kernel.org/r/20210713080035.7464-2-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mike Rapoport 2021-09-07 19:54:52 -07:00 committed by Linus Torvalds
parent ac3332c447
commit 859a85ddf9
8 changed files with 11 additions and 75 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
drivers/base/node.c
View file

@ -768,8 +768,6 @@ int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
static int __ref get_nid_for_pfn(unsigned long pfn)
{
if (!pfn_valid_within(pfn))
return -1;
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
if (system_state < SYSTEM_RUNNING)
return early_pfn_to_nid(pfn);

12
include/linux/mmzone.h
View file

@ -1525,18 +1525,6 @@ void sparse_init(void);
#define subsection_map_init(_pfn, _nr_pages) do {} while (0)
#endif /* CONFIG_SPARSEMEM */
/*
* If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
* need to check pfn validity within that MAX_ORDER_NR_PAGES block.
* pfn_valid_within() should be used in this case; we optimise this away
* when we have no holes within a MAX_ORDER_NR_PAGES block.
*/
#ifdef CONFIG_HOLES_IN_ZONE
#define pfn_valid_within(pfn) pfn_valid(pfn)
#else
#define pfn_valid_within(pfn) (1)
#endif
#endif /* !__GENERATING_BOUNDS.H */
#endif /* !__ASSEMBLY__ */
#endif /* _LINUX_MMZONE_H */

3
mm/Kconfig
View file

@ -96,9 +96,6 @@ config HAVE_FAST_GUP
depends on MMU
bool
config HOLES_IN_ZONE
bool
# Don't discard allocated memory used to track "memory" and "reserved" memblocks
# after early boot, so it can still be used to test for validity of memory.
# Also, memblocks are updated with memory hot(un)plug.

20
mm/compaction.c
View file

@ -306,16 +306,14 @@ __reset_isolation_pfn(struct zone *zone, unsigned long pfn, bool check_source,
* is necessary for the block to be a migration source/target.
*/
do {
if (pfn_valid_within(pfn)) {
if (check_source && PageLRU(page)) {
clear_pageblock_skip(page);
return true;
}
if (check_source && PageLRU(page)) {
clear_pageblock_skip(page);
return true;
}
if (check_target && PageBuddy(page)) {
clear_pageblock_skip(page);
return true;
}
if (check_target && PageBuddy(page)) {
clear_pageblock_skip(page);
return true;
}
page += (1 << PAGE_ALLOC_COSTLY_ORDER);
@ -585,8 +583,6 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
break;
nr_scanned++;
if (!pfn_valid_within(blockpfn))
goto isolate_fail;
/*
* For compound pages such as THP and hugetlbfs, we can save
@ -885,8 +881,6 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
cond_resched();
}
if (!pfn_valid_within(low_pfn))
goto isolate_fail;
nr_scanned++;
page = pfn_to_page(low_pfn);

4
mm/memory_hotplug.c
View file

@ -1308,10 +1308,6 @@ struct zone *test_pages_in_a_zone(unsigned long start_pfn,
for (; pfn < sec_end_pfn && pfn < end_pfn;
pfn += MAX_ORDER_NR_PAGES) {
i = 0;
/* This is just a CONFIG_HOLES_IN_ZONE check.*/
while ((i < MAX_ORDER_NR_PAGES) &&
!pfn_valid_within(pfn + i))
i++;
if (i == MAX_ORDER_NR_PAGES || pfn + i >= end_pfn)
continue;
/* Check if we got outside of the zone */

24
mm/page_alloc.c
View file

@ -594,8 +594,6 @@ static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
static int page_is_consistent(struct zone *zone, struct page *page)
{
if (!pfn_valid_within(page_to_pfn(page)))
return 0;
if (zone != page_zone(page))
return 0;
@ -1025,16 +1023,12 @@ buddy_merge_likely(unsigned long pfn, unsigned long buddy_pfn,
if (order >= MAX_ORDER - 2)
return false;
if (!pfn_valid_within(buddy_pfn))
return false;
combined_pfn = buddy_pfn & pfn;
higher_page = page + (combined_pfn - pfn);
buddy_pfn = __find_buddy_pfn(combined_pfn, order + 1);
higher_buddy = higher_page + (buddy_pfn - combined_pfn);
return pfn_valid_within(buddy_pfn) &&
page_is_buddy(higher_page, higher_buddy, order + 1);
return page_is_buddy(higher_page, higher_buddy, order + 1);
}
/*
@ -1095,8 +1089,6 @@ static inline void __free_one_page(struct page *page,
buddy_pfn = __find_buddy_pfn(pfn, order);
buddy = page + (buddy_pfn - pfn);
if (!pfn_valid_within(buddy_pfn))
goto done_merging;
if (!page_is_buddy(page, buddy, order))
goto done_merging;
/*
@ -1754,9 +1746,7 @@ void __init memblock_free_pages(struct page *page, unsigned long pfn,
/*
* Check that the whole (or subset of) a pageblock given by the interval of
* [start_pfn, end_pfn) is valid and within the same zone, before scanning it
* with the migration of free compaction scanner. The scanners then need to
* use only pfn_valid_within() check for arches that allow holes within
* pageblocks.
* with the migration of free compaction scanner.
*
* Return struct page pointer of start_pfn, or NULL if checks were not passed.
*
@ -1872,8 +1862,6 @@ static inline void __init pgdat_init_report_one_done(void)
*/
static inline bool __init deferred_pfn_valid(unsigned long pfn)
{
if (!pfn_valid_within(pfn))
return false;
if (!(pfn & (pageblock_nr_pages - 1)) && !pfn_valid(pfn))
return false;
return true;
@ -2520,11 +2508,6 @@ static int move_freepages(struct zone *zone,
int pages_moved = 0;
for (pfn = start_pfn; pfn <= end_pfn;) {
if (!pfn_valid_within(pfn)) {
pfn++;
continue;
}
page = pfn_to_page(pfn);
if (!PageBuddy(page)) {
/*
@ -8814,9 +8797,6 @@ struct page *has_unmovable_pages(struct zone *zone, struct page *page,
}
for (; iter < pageblock_nr_pages - offset; iter++) {
if (!pfn_valid_within(pfn + iter))
continue;
page = pfn_to_page(pfn + iter);
/*

7
mm/page_isolation.c
View file

@ -93,8 +93,7 @@ static void unset_migratetype_isolate(struct page *page, unsigned migratetype)
buddy_pfn = __find_buddy_pfn(pfn, order);
buddy = page + (buddy_pfn - pfn);
if (pfn_valid_within(buddy_pfn) &&
!is_migrate_isolate_page(buddy)) {
if (!is_migrate_isolate_page(buddy)) {
__isolate_free_page(page, order);
isolated_page = true;
}
@ -250,10 +249,6 @@ __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))
/*

14
mm/page_owner.c
View file

@ -276,9 +276,6 @@ void pagetypeinfo_showmixedcount_print(struct seq_file *m,
pageblock_mt = get_pageblock_migratetype(page);
for (; pfn < block_end_pfn; pfn++) {
if (!pfn_valid_within(pfn))
continue;
/* The pageblock is online, no need to recheck. */
page = pfn_to_page(pfn);
@ -479,10 +476,6 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos)
continue;
}
/* Check for holes within a MAX_ORDER area */
if (!pfn_valid_within(pfn))
continue;
page = pfn_to_page(pfn);
if (PageBuddy(page)) {
unsigned long freepage_order = buddy_order_unsafe(page);
@ -560,14 +553,9 @@ static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone)
block_end_pfn = min(block_end_pfn, end_pfn);
for (; pfn < block_end_pfn; pfn++) {
struct page *page;
struct page *page = pfn_to_page(pfn);
struct page_ext *page_ext;
if (!pfn_valid_within(pfn))
continue;
page = pfn_to_page(pfn);
if (page_zone(page) != zone)
continue;