The patch titled
Subject: mm: remove migration for HugePage in isolate_single_pageblock()
has been added to the -mm mm-unstable branch. Its filename is
mm-remove-migration-for-hugepage-in-isolate_single_pageblock.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-remove-migration-for-hugepage-in-isolate_single_pageblock.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Subject: mm: remove migration for HugePage in isolate_single_pageblock()
Date: Tue, 20 Aug 2024 11:26:30 +0800
The gigantic page size may larger than memory block size, so memory
offline always fails in this case after commit b2c9e2fbba32 ("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.
Link: https://lkml.kernel.org/r/20240820032630.1894770-1-wangkefeng.wang@xxxxxxxxxx
Fixes: b2c9e2fbba32 ("mm: make alloc_contig_range work at pageblock granularity")
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: Zi Yan <ziy@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_isolation.c | 28 +++-------------------------
1 file changed, 3 insertions(+), 25 deletions(-)
--- a/mm/page_isolation.c~mm-remove-migration-for-hugepage-in-isolate_single_pageblock
+++ a/mm/page_isolation.c
@@ -403,30 +403,8 @@ static int isolate_single_pageblock(unsi
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(unsi
*/
VM_WARN_ON_ONCE_PAGE(PageLRU(page), page);
VM_WARN_ON_ONCE_PAGE(__PageMovable(page), page);
-#endif
+
goto failed;
}
_
Patches currently in -mm which might be from wangkefeng.wang@xxxxxxxxxx are
mm-hugetlb-remove-left-over-comment-about-follow_huge_foo.patch
mm-memory_hotplug-remove-head-variable-in-do_migrate_range.patch
mm-memory-failure-add-unmap_posioned_folio.patch
mm-memory_hotplug-check-hwpoisoned-page-firstly-in-do_migrate_range.patch
mm-migrate-add-isolate_folio_to_list.patch
mm-memory_hotplug-unify-huge-lru-non-lru-movable-folio-isolation.patch
mm-remove-migration-for-hugepage-in-isolate_single_pageblock.patch
