On Fri, Jun 26, 2020 at 10:23:43PM +0530, Naresh Kamboju wrote:
On Wed, 24 Jun 2020 at 20:32, nao.horiguchi@gmail.com wrote:
From: Oscar Salvador osalvador@suse.de
Merging soft_offline_huge_page and __soft_offline_page let us get rid of quite some duplicated code, and makes the code much easier to follow.
Now, __soft_offline_page will handle both normal and hugetlb pages.
Note that move put_page() block to the beginning of page_handle_poison() with drain_all_pages() in order to make sure that the target page is freed and sent into free list to make take_page_off_buddy() work properly.
Signed-off-by: Oscar Salvador osalvador@suse.de Signed-off-by: Naoya Horiguchi naoya.horiguchi@nec.com
ChangeLog v2 -> v3:
- use page_is_file_lru() instead of page_is_file_cache(),
- add description about put_page() and drain_all_pages().
- fix coding style warnings by checkpatch.pl
mm/memory-failure.c | 185 ++++++++++++++++++++------------------------ 1 file changed, 86 insertions(+), 99 deletions(-)
diff --git v5.8-rc1-mmots-2020-06-20-21-44/mm/memory-failure.c v5.8-rc1-mmots-2020-06-20-21-44_patched/mm/memory-failure.c index f744eb90c15c..22c904f6d17a 100644 --- v5.8-rc1-mmots-2020-06-20-21-44/mm/memory-failure.c +++ v5.8-rc1-mmots-2020-06-20-21-44_patched/mm/memory-failure.c @@ -78,14 +78,36 @@ EXPORT_SYMBOL_GPL(hwpoison_filter_dev_minor); EXPORT_SYMBOL_GPL(hwpoison_filter_flags_mask); EXPORT_SYMBOL_GPL(hwpoison_filter_flags_value);
-static void page_handle_poison(struct page *page, bool release) +static bool page_handle_poison(struct page *page, bool hugepage_or_freepage, bool release) {
if (release) {put_page(page);drain_all_pages(page_zone(page));}if (hugepage_or_freepage) {/** Doing this check for free pages is also fine since dissolve_free_huge_page* returns 0 for non-hugetlb pages as well.*/if (dissolve_free_huge_page(page) || !take_page_off_buddy(page))/** The hugetlb page can end up being enqueued back into* the freelists by means of:* unmap_and_move_huge_page* putback_active_hugepage* put_page->free_huge_page* enqueue_huge_page* If this happens, we might lose the race against an allocation.*/return false;} SetPageHWPoison(page);
if (release)put_page(page); page_ref_inc(page); num_poisoned_pages_inc();
return true;}
static int hwpoison_filter_dev(struct page *p) @@ -1718,63 +1740,52 @@ static int get_any_page(struct page *page, unsigned long pfn) return ret; }
-static int soft_offline_huge_page(struct page *page) +static bool isolate_page(struct page *page, struct list_head *pagelist) {
int ret;unsigned long pfn = page_to_pfn(page);struct page *hpage = compound_head(page);LIST_HEAD(pagelist);
bool isolated = false;bool lru = PageLRU(page);if (PageHuge(page)) {isolated = isolate_huge_page(page, pagelist);} else {if (lru)isolated = !isolate_lru_page(page);elseisolated = !isolate_movable_page(page, ISOLATE_UNEVICTABLE);if (isolated)list_add(&page->lru, pagelist);
/** This double-check of PageHWPoison is to avoid the race with* memory_failure(). See also comment in __soft_offline_page().*/lock_page(hpage);if (PageHWPoison(hpage)) {unlock_page(hpage);put_page(hpage);pr_info("soft offline: %#lx hugepage already poisoned\n", pfn);return -EBUSY; }unlock_page(hpage);ret = isolate_huge_page(hpage, &pagelist);
if (isolated && lru)inc_node_page_state(page, NR_ISOLATED_ANON +page_is_file_lru(page));/*
* get_any_page() and isolate_huge_page() takes a refcount each,* so need to drop one here.
* If we succeed to isolate the page, we grabbed another refcount on* the page, so we can safely drop the one we got from get_any_pages().* If we failed to isolate the page, it means that we cannot go further* and we will return an error, so drop the reference we got from* get_any_pages() as well. */
put_page(hpage);if (!ret) {pr_info("soft offline: %#lx hugepage failed to isolate\n", pfn);return -EBUSY;}ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,MIGRATE_SYNC, MR_MEMORY_FAILURE);if (ret) {pr_info("soft offline: %#lx: hugepage migration failed %d, type %lx (%pGp)\n",pfn, ret, page->flags, &page->flags);if (!list_empty(&pagelist))putback_movable_pages(&pagelist);if (ret > 0)ret = -EIO;} else {/** We set PG_hwpoison only when we were able to take the page* off the buddy.*/if (!dissolve_free_huge_page(page) && take_page_off_buddy(page))page_handle_poison(page, false);elseret = -EBUSY;}return ret;
put_page(page);return isolated;}
+/*
- __soft_offline_page handles hugetlb-pages and non-hugetlb pages.
- If the page is a non-dirty unmapped page-cache page, it simply invalidates.
- If the page is mapped, it migrates the contents over.
- */
static int __soft_offline_page(struct page *page) {
int ret;
int ret = 0; unsigned long pfn = page_to_pfn(page);struct page *hpage = compound_head(page);const char *msg_page[] = {"page", "hugepage"};bool huge = PageHuge(page);LIST_HEAD(pagelist); /* * Check PageHWPoison again inside page lock because PageHWPoison@@ -1783,98 +1794,74 @@ static int __soft_offline_page(struct page *page) * so there's no race between soft_offline_page() and memory_failure(). */ lock_page(page);
wait_on_page_writeback(page);
if (!PageHuge(page))wait_on_page_writeback(page); if (PageHWPoison(page)) { unlock_page(page); put_page(page); pr_info("soft offline: %#lx page already poisoned\n", pfn); return -EBUSY; }
/** Try to invalidate first. This should work for* non dirty unmapped page cache pages.*/ret = invalidate_inode_page(page);
if (!PageHuge(page))/** Try to invalidate first. This should work for* non dirty unmapped page cache pages.*/ret = invalidate_inode_page(page); unlock_page(page);/* * RED-PEN would be better to keep it isolated here, but we * would need to fix isolation locking first. */
if (ret == 1) {
if (ret) { pr_info("soft_offline: %#lx: invalidated\n", pfn);
page_handle_poison(page, true);
page_handle_poison(page, false, true);arm64 build failed on linux-next 20200626 tag
make -sk KBUILD_BUILD_USER=TuxBuild -C/linux -j16 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- HOSTCC=gcc CC="sccache aarch64-linux-gnu-gcc" O=build Image 79 # 80 ../mm/memory-failure.c: In function ‘__soft_offline_page’: 81 ../mm/memory-failure.c:1827:3: error: implicit declaration of function ‘page_handle_poison’; did you mean ‘page_init_poison’? [-Werror=implicit-function-declaration] 82 1827 | page_handle_poison(page, false, true); 83 | ^~~~~~~~~~~~~~~~~~ 84 | page_init_poison
Thanks for reporting, Naresh, Qian Cai.
page_handle_poison() is now defined in #ifdef CONFIG_HWPOISON_INJECT block, which is not correct because this function is used in non-injection code path. I'd like to move this function out of the block and it affects multiple patches in this series, so maybe I have to update/resend the whole series, but I like to wait for a few days for other reviews, so for quick fix for linux-next I suggest the following one.
Andrew, could you append this diff on top of this series on mmotm?
Thanks, Naoya Horiguchi --- diff --git a/mm/memory-failure.c b/mm/memory-failure.c index e90ddddab397..b49590bc5615 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -78,38 +78,6 @@ EXPORT_SYMBOL_GPL(hwpoison_filter_dev_minor); EXPORT_SYMBOL_GPL(hwpoison_filter_flags_mask); EXPORT_SYMBOL_GPL(hwpoison_filter_flags_value);
-static bool page_handle_poison(struct page *page, bool hugepage_or_freepage, bool release) -{ - if (release) { - put_page(page); - drain_all_pages(page_zone(page)); - } - - if (hugepage_or_freepage) { - /* - * Doing this check for free pages is also fine since dissolve_free_huge_page - * returns 0 for non-hugetlb pages as well. - */ - if (dissolve_free_huge_page(page) || !take_page_off_buddy(page)) - /* - * The hugetlb page can end up being enqueued back into - * the freelists by means of: - * unmap_and_move_huge_page - * putback_active_hugepage - * put_page->free_huge_page - * enqueue_huge_page - * If this happens, we might lose the race against an allocation. - */ - return false; - } - - SetPageHWPoison(page); - page_ref_inc(page); - num_poisoned_pages_inc(); - - return true; -} - static int hwpoison_filter_dev(struct page *p) { struct address_space *mapping; @@ -204,6 +172,38 @@ int hwpoison_filter(struct page *p)
EXPORT_SYMBOL_GPL(hwpoison_filter);
+static bool page_handle_poison(struct page *page, bool hugepage_or_freepage, bool release) +{ + if (release) { + put_page(page); + drain_all_pages(page_zone(page)); + } + + if (hugepage_or_freepage) { + /* + * Doing this check for free pages is also fine since dissolve_free_huge_page + * returns 0 for non-hugetlb pages as well. + */ + if (dissolve_free_huge_page(page) || !take_page_off_buddy(page)) + /* + * The hugetlb page can end up being enqueued back into + * the freelists by means of: + * unmap_and_move_huge_page + * putback_active_hugepage + * put_page->free_huge_page + * enqueue_huge_page + * If this happens, we might lose the race against an allocation. + */ + return false; + } + + SetPageHWPoison(page); + page_ref_inc(page); + num_poisoned_pages_inc(); + + return true; +} + /* * Kill all processes that have a poisoned page mapped and then isolate * the page.