On Fri, Jun 26, 2020 at 10:23:43PM +0530, Naresh Kamboju wrote: > On Wed, 24 Jun 2020 at 20:32, <nao.horiguchi@xxxxxxxxx> wrote: > > > > From: Oscar Salvador <osalvador@xxxxxxx> > > > > 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@xxxxxxx> > > Signed-off-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx> > > --- > > 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); > > + else > > + isolated = !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); > > - else > > - ret = -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.