| Message ID | 20200922135650.1634-12-osalvador@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | HWPOISON: soft offline rework | expand |
On Tue, Sep 22, 2020 at 03:56:47PM +0200, Oscar Salvador wrote: > 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@suse.de> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
diff --git a/mm/madvise.c b/mm/madvise.c index f3a86d547ceb..5ab978b828f0 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -896,11 +896,6 @@ 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 a/mm/memory-failure.c b/mm/memory-failure.c index 7c122cca9f31..087f070b06b5 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1802,7 +1802,7 @@ 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)) @@ -1906,7 +1906,7 @@ 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();
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@suse.de> --- mm/madvise.c | 5 ----- mm/memory-failure.c | 4 ++-- 2 files changed, 2 insertions(+), 7 deletions(-)