The patch titled
Subject: mm, isolation: avoid checking unmovable pages across pageblock boundary
has been added to the -mm tree. Its filename is
mm-isolation-avoid-checking-unmovable-pages-across-pageblock-boundary.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-isolation-avoid-checking-unmovable-pages-across-pageblock-boundary.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-isolation-avoid-checking-unmovable-pages-across-pageblock-boundary.patch
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------------------------------------------------------
From: Li Xinhai <lixinhai.lxh@xxxxxxxxx>
Subject: mm, isolation: avoid checking unmovable pages across pageblock boundary
In has_unmovable_pages(), the page parameter would not always be the first
page within a pageblock (see how the page pointer is passed in from
start_isolate_page_range() after call __first_valid_page()), so that would
cause checking unmovable pages span two pageblocks.
After this patch, the checking is enforced within one pageblock no matter
the page is first one or not, and obey the semantics of this function.
This issue is found by code inspection.
Link: https://lkml.kernel.org/r/20200824065811.383266-1-lixinhai.lxh@xxxxxxxxx
Signed-off-by: Li Xinhai <lixinhai.lxh@xxxxxxxxx>
Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/mm/page_alloc.c~mm-isolation-avoid-checking-unmovable-pages-across-pageblock-boundary
+++ a/mm/page_alloc.c
@@ -8218,6 +8218,7 @@ struct page *has_unmovable_pages(struct
{
unsigned long iter = 0;
unsigned long pfn = page_to_pfn(page);
+ unsigned long offset = pfn % pageblock_nr_pages;
if (is_migrate_cma_page(page)) {
/*
@@ -8231,7 +8232,7 @@ struct page *has_unmovable_pages(struct
return page;
}
- for (; iter < pageblock_nr_pages; iter++) {
+ for (; iter < pageblock_nr_pages - offset; iter++) {
if (!pfn_valid_within(pfn + iter))
continue;
_
Patches currently in -mm which might be from lixinhai.lxh@xxxxxxxxx are
mm-isolation-avoid-checking-unmovable-pages-across-pageblock-boundary.patch
