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mm: page_isolation: enable arbitrary range page isolation.
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Now start_isolate_page_range() is ready to handle arbitrary range
isolation, so move the alignment check/adjustment into the function body. 
Do the same for its counterpart undo_isolate_page_range(). 
alloc_contig_range(), its caller, can pass an arbitrary range instead of a
MAX_ORDER_NR_PAGES aligned one.

Link: https://lkml.kernel.org/r/20220425143118.2850746-5-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric Ren <renzhengeek@gmail.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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@x-y-z @akpm00
x-y-z authored and akpm00 committed May 13, 2022
1 parent b2c9e2f commit 6e263ff
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Showing 2 changed files with 18 additions and 31 deletions.
16 changes: 2 additions & 14 deletions mm/page_alloc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -8956,16 +8956,6 @@ void *__init alloc_large_system_hash(const char *tablename,
}

#ifdef CONFIG_CONTIG_ALLOC
static unsigned long pfn_max_align_down(unsigned long pfn)
{
return ALIGN_DOWN(pfn, MAX_ORDER_NR_PAGES);
}

static unsigned long pfn_max_align_up(unsigned long pfn)
{
return ALIGN(pfn, MAX_ORDER_NR_PAGES);
}

#if defined(CONFIG_DYNAMIC_DEBUG) || \
(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
/* Usage: See admin-guide/dynamic-debug-howto.rst */
Expand Down Expand Up @@ -9107,8 +9097,7 @@ int alloc_contig_range(unsigned long start, unsigned long end,
* put back to page allocator so that buddy can use them.
*/

ret = start_isolate_page_range(pfn_max_align_down(start),
pfn_max_align_up(end), migratetype, 0, gfp_mask);
ret = start_isolate_page_range(start, end, migratetype, 0, gfp_mask);
if (ret)
goto done;

Expand Down Expand Up @@ -9189,8 +9178,7 @@ int alloc_contig_range(unsigned long start, unsigned long end,
free_contig_range(end, outer_end - end);

done:
undo_isolate_page_range(pfn_max_align_down(start),
pfn_max_align_up(end), migratetype);
undo_isolate_page_range(start, end, migratetype);
return ret;
}
EXPORT_SYMBOL(alloc_contig_range);
Expand Down
33 changes: 16 additions & 17 deletions mm/page_isolation.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -444,7 +444,6 @@ static int isolate_single_pageblock(unsigned long boundary_pfn, gfp_t gfp_flags,
* 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.
* start_pfn/end_pfn must be aligned to pageblock_order.
* @migratetype: Migrate type to set in error recovery.
* @flags: The following flags are allowed (they can be combined in
* a bit mask)
Expand Down Expand Up @@ -491,33 +490,33 @@ int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
{
unsigned long pfn;
struct page *page;
/* isolation is done at page block granularity */
unsigned long isolate_start = ALIGN_DOWN(start_pfn, pageblock_nr_pages);
unsigned long isolate_end = ALIGN(end_pfn, pageblock_nr_pages);
int ret;

BUG_ON(!IS_ALIGNED(start_pfn, pageblock_nr_pages));
BUG_ON(!IS_ALIGNED(end_pfn, pageblock_nr_pages));

/* isolate [start_pfn, start_pfn + pageblock_nr_pages) pageblock */
ret = isolate_single_pageblock(start_pfn, gfp_flags, false);
/* isolate [isolate_start, isolate_start + pageblock_nr_pages) pageblock */
ret = isolate_single_pageblock(isolate_start, gfp_flags, false);
if (ret)
return ret;

/* isolate [end_pfn - pageblock_nr_pages, end_pfn) pageblock */
ret = isolate_single_pageblock(end_pfn, gfp_flags, true);
/* isolate [isolate_end - pageblock_nr_pages, isolate_end) pageblock */
ret = isolate_single_pageblock(isolate_end, gfp_flags, true);
if (ret) {
unset_migratetype_isolate(pfn_to_page(start_pfn), migratetype);
unset_migratetype_isolate(pfn_to_page(isolate_start), migratetype);
return ret;
}

/* skip isolated pageblocks at the beginning and end */
for (pfn = start_pfn + pageblock_nr_pages;
pfn < end_pfn - pageblock_nr_pages;
for (pfn = isolate_start + pageblock_nr_pages;
pfn < isolate_end - pageblock_nr_pages;
pfn += pageblock_nr_pages) {
page = __first_valid_page(pfn, pageblock_nr_pages);
if (page && set_migratetype_isolate(page, migratetype, flags,
start_pfn, end_pfn)) {
undo_isolate_page_range(start_pfn, pfn, migratetype);
undo_isolate_page_range(isolate_start, pfn, migratetype);
unset_migratetype_isolate(
pfn_to_page(end_pfn - pageblock_nr_pages),
pfn_to_page(isolate_end - pageblock_nr_pages),
migratetype);
return -EBUSY;
}
Expand All @@ -533,12 +532,12 @@ void undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
{
unsigned long pfn;
struct page *page;
unsigned long isolate_start = ALIGN_DOWN(start_pfn, pageblock_nr_pages);
unsigned long isolate_end = ALIGN(end_pfn, pageblock_nr_pages);

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;
for (pfn = isolate_start;
pfn < isolate_end;
pfn += pageblock_nr_pages) {
page = __first_valid_page(pfn, pageblock_nr_pages);
if (!page || !is_migrate_isolate_page(page))
Expand Down

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