On Mon, Mar 25, 2024 at 11:48:13AM -0700, Andrew Morton wrote: > On Mon, 25 Mar 2024 08:57:52 +0100 Vlastimil Babka <vbabka@xxxxxxx> wrote: > > Reported-by: Luis Chamberlain <mcgrof@xxxxxxxxxx> > > Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218227 > > Fixes: 9c5ccf2db04b ("mm: remove HUGETLB_PAGE_DTOR") > > Cc: <stable@xxxxxxxxxxxxxxx> > > Thanks. > > The patch doesn't work as a standalone thing. No, it depends on both mm: support page_mapcount() on page_has_type() pages mm: create FOLIO_FLAG_FALSE and FOLIO_TYPE_OPS macros I was assuming both would get backported as dependencies. If you want a standalone patch, something like this would do the trick. > Matthew, could you please redo this patch (and its vmcore fix) and send > as a standalone -stable patch? It could be that the "Various > significant MM patches" will need a redo afterwards. I'd rather keep the mapcount patch separate for upstream purposes. I've build-tested against 6.6.22 with allmodconfig and then with HUGETLB=n (but otherwise allmodconfig) diff --git a/include/linux/mm.h b/include/linux/mm.h index bf5d0b1b16f4..5e15004eab8c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1192,6 +1192,9 @@ static inline int page_mapcount(struct page *page) { int mapcount = atomic_read(&page->_mapcount) + 1; + /* Handle page_has_type() pages */ + if (mapcount < 0) + mapcount = 0; if (unlikely(PageCompound(page))) mapcount += folio_entire_mapcount(page_folio(page)); diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 5c02720c53a5..4d5f750551c5 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -190,7 +190,6 @@ enum pageflags { /* At least one page in this folio has the hwpoison flag set */ PG_has_hwpoisoned = PG_error, - PG_hugetlb = PG_active, PG_large_rmappable = PG_workingset, /* anon or file-backed */ }; @@ -815,29 +814,6 @@ TESTPAGEFLAG_FALSE(LargeRmappable, large_rmappable) #define PG_head_mask ((1UL << PG_head)) -#ifdef CONFIG_HUGETLB_PAGE -int PageHuge(struct page *page); -SETPAGEFLAG(HugeTLB, hugetlb, PF_SECOND) -CLEARPAGEFLAG(HugeTLB, hugetlb, PF_SECOND) - -/** - * folio_test_hugetlb - Determine if the folio belongs to hugetlbfs - * @folio: The folio to test. - * - * Context: Any context. Caller should have a reference on the folio to - * prevent it from being turned into a tail page. - * Return: True for hugetlbfs folios, false for anon folios or folios - * belonging to other filesystems. - */ -static inline bool folio_test_hugetlb(struct folio *folio) -{ - return folio_test_large(folio) && - test_bit(PG_hugetlb, folio_flags(folio, 1)); -} -#else -TESTPAGEFLAG_FALSE(Huge, hugetlb) -#endif - #ifdef CONFIG_TRANSPARENT_HUGEPAGE /* * PageHuge() only returns true for hugetlbfs pages, but not for @@ -893,18 +869,6 @@ PAGEFLAG_FALSE(HasHWPoisoned, has_hwpoisoned) TESTSCFLAG_FALSE(HasHWPoisoned, has_hwpoisoned) #endif -/* - * Check if a page is currently marked HWPoisoned. Note that this check is - * best effort only and inherently racy: there is no way to synchronize with - * failing hardware. - */ -static inline bool is_page_hwpoison(struct page *page) -{ - if (PageHWPoison(page)) - return true; - return PageHuge(page) && PageHWPoison(compound_head(page)); -} - /* * For pages that are never mapped to userspace (and aren't PageSlab), * page_type may be used. Because it is initialised to -1, we invert the @@ -921,6 +885,7 @@ static inline bool is_page_hwpoison(struct page *page) #define PG_offline 0x00000100 #define PG_table 0x00000200 #define PG_guard 0x00000400 +#define PG_hugetlb 0x00000800 #define PageType(page, flag) \ ((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE) @@ -1012,6 +977,37 @@ PAGE_TYPE_OPS(Table, table, pgtable) */ PAGE_TYPE_OPS(Guard, guard, guard) +#ifdef CONFIG_HUGETLB_PAGE +PAGE_TYPE_OPS(HeadHugeTLB, hugetlb, hugetlb) + +/** + * PageHuge - Determine if the folio belongs to hugetlbfs. + * @page: The page to test. + * + * Context: Any context. + * Return: True for hugetlbfs folios, false for anon folios or folios + * belonging to other filesystems. + */ +static inline bool PageHuge(const struct page *page) +{ + return folio_test_hugetlb(page_folio(page)); +} +#else +TESTPAGEFLAG_FALSE(Huge, hugetlb) +#endif + +/* + * Check if a page is currently marked HWPoisoned. Note that this check is + * best effort only and inherently racy: there is no way to synchronize with + * failing hardware. + */ +static inline bool is_page_hwpoison(struct page *page) +{ + if (PageHWPoison(page)) + return true; + return PageHuge(page) && PageHWPoison(compound_head(page)); +} + extern bool is_free_buddy_page(struct page *page); PAGEFLAG(Isolated, isolated, PF_ANY); @@ -1078,7 +1074,7 @@ static __always_inline void __ClearPageAnonExclusive(struct page *page) */ #define PAGE_FLAGS_SECOND \ (0xffUL /* order */ | 1UL << PG_has_hwpoisoned | \ - 1UL << PG_hugetlb | 1UL << PG_large_rmappable) + 1UL << PG_large_rmappable) #define PAGE_FLAGS_PRIVATE \ (1UL << PG_private | 1UL << PG_private_2) diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h index 1478b9dd05fa..e010618f9326 100644 --- a/include/trace/events/mmflags.h +++ b/include/trace/events/mmflags.h @@ -135,6 +135,7 @@ IF_HAVE_PG_ARCH_X(arch_3) #define DEF_PAGETYPE_NAME(_name) { PG_##_name, __stringify(_name) } #define __def_pagetype_names \ + DEF_PAGETYPE_NAME(hugetlb), \ DEF_PAGETYPE_NAME(offline), \ DEF_PAGETYPE_NAME(guard), \ DEF_PAGETYPE_NAME(table), \ diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 2f675ef045d4..a2face7fbef8 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -675,8 +675,8 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_NUMBER(PG_head_mask); #define PAGE_BUDDY_MAPCOUNT_VALUE (~PG_buddy) VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE); -#ifdef CONFIG_HUGETLB_PAGE - VMCOREINFO_NUMBER(PG_hugetlb); +#define PAGE_HUGETLB_MAPCOUNT_VALUE (~PG_hugetlb) + VMCOREINFO_NUMBER(PAGE_HUGETLB_MAPCOUNT_VALUE); #define PAGE_OFFLINE_MAPCOUNT_VALUE (~PG_offline) VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE); #endif diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 5e6c4d367d33..30b713d330ca 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1630,7 +1630,7 @@ static inline void __clear_hugetlb_destructor(struct hstate *h, { lockdep_assert_held(&hugetlb_lock); - folio_clear_hugetlb(folio); + __folio_clear_hugetlb(folio); } /* @@ -1717,7 +1717,7 @@ static void add_hugetlb_folio(struct hstate *h, struct folio *folio, h->surplus_huge_pages_node[nid]++; } - folio_set_hugetlb(folio); + __folio_set_hugetlb(folio); folio_change_private(folio, NULL); /* * We have to set hugetlb_vmemmap_optimized again as above @@ -1971,7 +1971,7 @@ static void __prep_new_hugetlb_folio(struct hstate *h, struct folio *folio) { hugetlb_vmemmap_optimize(h, &folio->page); INIT_LIST_HEAD(&folio->lru); - folio_set_hugetlb(folio); + __folio_set_hugetlb(folio); hugetlb_set_folio_subpool(folio, NULL); set_hugetlb_cgroup(folio, NULL); set_hugetlb_cgroup_rsvd(folio, NULL); @@ -2074,22 +2074,6 @@ static bool prep_compound_gigantic_folio_for_demote(struct folio *folio, return __prep_compound_gigantic_folio(folio, order, true); } -/* - * PageHuge() only returns true for hugetlbfs pages, but not for normal or - * transparent huge pages. See the PageTransHuge() documentation for more - * details. - */ -int PageHuge(struct page *page) -{ - struct folio *folio; - - if (!PageCompound(page)) - return 0; - folio = page_folio(page); - return folio_test_hugetlb(folio); -} -EXPORT_SYMBOL_GPL(PageHuge); - /* * Find and lock address space (mapping) in write mode. *
