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 | 3 --- mm/memory-failure.c | 4 ++-- 2 files changed, 2 insertions(+), 5 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 3eee78abdbec..843f6fad3b89 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 @@ -919,9 +919,6 @@ static int madvise_inject_error(int behavior, */ put_page(page); - if (PageHWPoison(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 904dec64da6b..bd63f1f2e44e 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 @@ -1794,7 +1794,7 @@ 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)) @@ -1895,7 +1895,7 @@ int soft_offline_page(unsigned long pfn) if (PageHWPoison(page)) { pr_info("soft offline: %#lx page already poisoned\n", pfn); - return -EBUSY; + return 0; } get_online_mems(); -- 2.17.1