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mm: remove migration for HugePage in isolate_single_pageblock()

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The gigantic page size may larger than memory block size, so memory
offline always fails in this case after commit b2c9e2fbba ("mm: make
alloc_contig_range work at pageblock granularity"),

offline_pages
  start_isolate_page_range
    start_isolate_page_range(isolate_before=true)
      isolate [isolate_start, isolate_start + pageblock_nr_pages)
    start_isolate_page_range(isolate_before=false)
      isolate [isolate_end - pageblock_nr_pages, isolate_end) pageblock
       	__alloc_contig_migrate_range
          isolate_migratepages_range
            isolate_migratepages_block
              isolate_or_dissolve_huge_page
                if (hstate_is_gigantic(h))
                    return -ENOMEM;

[   15.815756] memory offlining [mem 0x3c0000000-0x3c7ffffff] failed due to failure to isolate range

Gigantic PageHuge is bigger than a pageblock, but since it is freed as
order-0 pages, its pageblocks after being freed will get to the right
free list.  There is no need to have special handling code for them in
start_isolate_page_range().  For both alloc_contig_range() and memory
offline cases, the migration code after start_isolate_page_range() will
be able to migrate gigantic PageHuge when possible.  Let's clean up
start_isolate_page_range() and fix the aforementioned memory offline
failure issue all together.

Let's clean up start_isolate_page_range() and fix the aforementioned
memory offline failure issue all together.

Link: https://lkml.kernel.org/r/20240820032630.1894770-1-wangkefeng.wang@huawei.com
Fixes: b2c9e2fbba ("mm: make alloc_contig_range work at pageblock granularity")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Kefeng Wang 2024-08-20 11:26:30 +08:00 committed by Andrew Morton
parent 49029c4db3
commit cd5f3193b4
1 changed files with 3 additions and 25 deletions
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28
mm/page_isolation.c
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@ -403,30 +403,8 @@ static int isolate_single_pageblock(unsigned long boundary_pfn, int flags,
unsigned long head_pfn = page_to_pfn(head);
unsigned long nr_pages = compound_nr(head);
if (head_pfn + nr_pages <= boundary_pfn) {
pfn = head_pfn + nr_pages;
continue;
}
#if defined CONFIG_COMPACTION || defined CONFIG_CMA
if (PageHuge(page)) {
int page_mt = get_pageblock_migratetype(page);
struct compact_control cc = {
.nr_migratepages = 0,
.order = -1,
.zone = page_zone(pfn_to_page(head_pfn)),
.mode = MIGRATE_SYNC,
.ignore_skip_hint = true,
.no_set_skip_hint = true,
.gfp_mask = gfp_flags,
.alloc_contig = true,
};
INIT_LIST_HEAD(&cc.migratepages);
ret = __alloc_contig_migrate_range(&cc, head_pfn,
head_pfn + nr_pages, page_mt);
if (ret)
goto failed;
if (head_pfn + nr_pages <= boundary_pfn ||
PageHuge(page)) {
pfn = head_pfn + nr_pages;
continue;
}
@ -440,7 +418,7 @@ static int isolate_single_pageblock(unsigned long boundary_pfn, int flags,
*/
VM_WARN_ON_ONCE_PAGE(PageLRU(page), page);
VM_WARN_ON_ONCE_PAGE(__PageMovable(page), page);
#endif
goto failed;
}