Commit 72c1584c authored Oct 29, 2024 by Baolin Wang Committed by Nanyong Sun Oct 29, 2024

mm: khugepaged: support shmem mTHP copy

mainline inclusion
from mainline-v6.12-rc1
commit dfa98f56d932fca3eaadaed8c17393fdfa00574d
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IAXCD2

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dfa98f56d932fca3eaadaed8c17393fdfa00574d

--------------------------------

Iterate each subpage in the large folio to copy, as preparation for
supporting shmem mTHP collapse.

Link: https://lkml.kernel.org/r/222d615b7c837eabb47a238126c5fdeff8aa5283.1724140601.git.baolin.wang@linux.alibaba.com


Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Conflicts:
	mm/khugepaged.c
[return val conflict for copy_mc_highpage, which is introduced
by commit 681be068 ("mm/hwpoison: return -EFAULT when copy fail
in copy_mc_[user]_highpage()")]
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>

parent 8a8270af

mm/khugepaged.c

+10 −5

Original line number	Diff line number	Diff line
		@@ -2070,18 +2070,23 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr,
		index = start;
		dst = folio_page(new_folio, 0);
		list_for_each_entry(folio, &pagelist, lru) {
		int i, nr_pages = folio_nr_pages(folio);

		while (index < folio->index) {
		clear_highpage(dst);
		index++;
		dst++;
		}
		if (copy_mc_highpage(dst, folio_page(folio, 0))) {

		for (i = 0; i < nr_pages; i++) {
		if (copy_mc_highpage(dst, folio_page(folio, i))) {
		result = SCAN_COPY_MC;
		goto rollback;
		}
		index++;
		dst++;
		}
		}
		while (index < end) {
		clear_highpage(dst);
		index++;