From: Oscar Salvador <osalvador@xxxxxxx>
Currently, there is an inconsistency when calling soft-offline from
different paths on a page that is already poisoned.
1) madvise:
madvise_inject_error skips any poisoned page and continues
the loop.
If that was the only page to madvise, it returns 0.
2) /sys/devices/system/memory/:
When calling soft_offline_page_store()->soft_offline_page(),
we return -EBUSY in case the page is already poisoned.
This is inconsistent with a) the above example and b)
memory_failure, where we return 0 if the page was poisoned.
Fix this by dropping the PageHWPoison() check in madvise_inject_error,
and let soft_offline_page return 0 if it finds the page already poisoned.
Please, note that this represents a user-api change, since now the
return error when calling soft_offline_page_store()->soft_offline_page()
will be different.
Signed-off-by: Oscar Salvador <osalvador@xxxxxxxx>
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
---
mm/madvise.c | 5 -----
mm/memory-failure.c | 4 ++--
2 files changed, 2 insertions(+), 7 deletions(-)
diff --git v5.8-rc7-mmotm-2020-07-27-18-18/mm/madvise.c v5.8-rc7-mmotm-2020-07-27-18-18_patched/mm/madvise.c
index a16dba21cdf6..5fa5f66468b3 100644
--- v5.8-rc7-mmotm-2020-07-27-18-18/mm/madvise.c
+++ v5.8-rc7-mmotm-2020-07-27-18-18_patched/mm/madvise.c
@@ -910,11 +910,6 @@ static int madvise_inject_error(int behavior,
*/
size = page_size(compound_head(page));
- if (PageHWPoison(page)) {
- put_page(page);
- continue;
- }
-
if (behavior == MADV_SOFT_OFFLINE) {
pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n",
pfn, start);
diff --git v5.8-rc7-mmotm-2020-07-27-18-18/mm/memory-failure.c v5.8-rc7-mmotm-2020-07-27-18-18_patched/mm/memory-failure.c
index 3a2cd094b77f..61e20b7dd81c 100644
--- v5.8-rc7-mmotm-2020-07-27-18-18/mm/memory-failure.c
+++ v5.8-rc7-mmotm-2020-07-27-18-18_patched/mm/memory-failure.c
@@ -1800,7 +1800,7 @@ static int __soft_offline_page(struct page *page)
unlock_page(page);
put_page(page);
pr_info("soft offline: %#lx page already poisoned\n", pfn);
- return -EBUSY;
+ return 0;
}
if (!PageHuge(page))
@@ -1904,7 +1904,7 @@ int soft_offline_page(unsigned long pfn, int flags)
pr_info("soft offline: %#lx page already poisoned\n", pfn);
if (flags & MF_COUNT_INCREASED)
put_page(page);
- return -EBUSY;
+ return 0;
}
get_online_mems();
--
2.17.1
