HWPOISON: Handle hardware poisoned pages in try_to_unmap (888b9f7c) · Commits · 戴 / test

When a page has the poison bit set replace the PTE with a poison entry. This causes the right error handling to be done later when a process runs into it. v2: add a new flag to not do that (needed for the memory-failure handler later) (Fengguang) v3: remove unnecessary is_migration_entry() test (Fengguang, Minchan) Reviewed-by:

Minchan Kim <minchan.kim@gmail.com> Reviewed-by:

Wu Fengguang <fengguang.wu@intel.com> Signed-off-by:

Andi Kleen <ak@linux.intel.com>

include/linux/rmap.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -93,6 +93,7 @@ enum ttu_flags {

		TTU_IGNORE_MLOCK = (1 << 8), /* ignore mlock */
		TTU_IGNORE_ACCESS = (1 << 9), /* don't age */
		TTU_IGNORE_HWPOISON = (1 << 10),/* corrupted page is recoverable */
		};
		#define TTU_ACTION(x) ((x) & TTU_ACTION_MASK)

mm/rmap.c

+8 −1

Original line number	Diff line number	Diff line
		@@ -820,7 +820,14 @@ static int try_to_unmap_one(struct page page, struct vm_area_struct vma,
		/* Update high watermark before we lower rss */
		update_hiwater_rss(mm);

		if (PageAnon(page)) {
		if (PageHWPoison(page) && !(flags & TTU_IGNORE_HWPOISON)) {
		if (PageAnon(page))
		dec_mm_counter(mm, anon_rss);
		else
		dec_mm_counter(mm, file_rss);
		set_pte_at(mm, address, pte,
		swp_entry_to_pte(make_hwpoison_entry(page)));
		} else if (PageAnon(page)) {
		swp_entry_t entry = { .val = page_private(page) };

		if (PageSwapCache(page)) {

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