From 06be6ff3d2ec8be806b859fc054a1909b16d2473 Mon Sep 17 00:00:00 2001 From: Oscar Salvador Date: Thu, 15 Oct 2020 20:07:05 -0700 Subject: mm,hwpoison: rework soft offline for free pages When trying to soft-offline a free page, we need to first take it off the buddy allocator. Once we know is out of reach, we can safely flag it as poisoned. take_page_off_buddy will be used to take a page meant to be poisoned off the buddy allocator. take_page_off_buddy calls break_down_buddy_pages, which splits a higher-order page in case our page belongs to one. Once the page is under our control, we call page_handle_poison to set it as poisoned and grab a refcount on it. Signed-off-by: Oscar Salvador Signed-off-by: Andrew Morton Acked-by: Naoya Horiguchi Cc: "Aneesh Kumar K.V" Cc: Aneesh Kumar K.V Cc: Aristeu Rozanski Cc: Dave Hansen Cc: David Hildenbrand Cc: Dmitry Yakunin Cc: Michal Hocko Cc: Mike Kravetz Cc: Oscar Salvador Cc: Qian Cai Cc: Tony Luck Link: https://lkml.kernel.org/r/20200922135650.1634-9-osalvador@suse.de Signed-off-by: Linus Torvalds --- mm/memory-failure.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'mm/memory-failure.c') diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 2ff4ba7fa99f..af7fb23b93ae 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -65,6 +65,13 @@ int sysctl_memory_failure_recovery __read_mostly = 1; atomic_long_t num_poisoned_pages __read_mostly = ATOMIC_LONG_INIT(0); +static void page_handle_poison(struct page *page) +{ + SetPageHWPoison(page); + page_ref_inc(page); + num_poisoned_pages_inc(); +} + #if defined(CONFIG_HWPOISON_INJECT) || defined(CONFIG_HWPOISON_INJECT_MODULE) u32 hwpoison_filter_enable = 0; @@ -1884,14 +1891,13 @@ static int soft_offline_in_use_page(struct page *page, int flags) static int soft_offline_free_page(struct page *page) { - int rc = dissolve_free_huge_page(page); + int rc = -EBUSY; - if (!rc) { - if (set_hwpoison_free_buddy_page(page)) - num_poisoned_pages_inc(); - else - rc = -EBUSY; + if (!dissolve_free_huge_page(page) && take_page_off_buddy(page)) { + page_handle_poison(page); + rc = 0; } + return rc; } -- cgit v1.2.3