Commit-ID: d63326928611600ad65baff54a70f53b02b3cdfe Gitweb: https://git.kernel.org/tip/d63326928611600ad65baff54a70f53b02b3cdfe Author: Rick Edgecombe <rick.p.edgeco...@intel.com> AuthorDate: Thu, 25 Apr 2019 17:11:35 -0700 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Tue, 30 Apr 2019 12:37:57 +0200
mm/hibernation: Make hibernation handle unmapped pages Make hibernate handle unmapped pages on the direct map when CONFIG_ARCH_HAS_SET_ALIAS=y is set. These functions allow for setting pages to invalid configurations, so now hibernate should check if the pages have valid mappings and handle if they are unmapped when doing a hibernate save operation. Previously this checking was already done when CONFIG_DEBUG_PAGEALLOC=y was configured. It does not appear to have a big hibernating performance impact. The speed of the saving operation before this change was measured as 819.02 MB/s, and after was measured at 813.32 MB/s. Before: [ 4.670938] PM: Wrote 171996 kbytes in 0.21 seconds (819.02 MB/s) After: [ 4.504714] PM: Wrote 178932 kbytes in 0.22 seconds (813.32 MB/s) Signed-off-by: Rick Edgecombe <rick.p.edgeco...@intel.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Acked-by: Pavel Machek <pa...@ucw.cz> Cc: <a...@linux-foundation.org> Cc: <ard.biesheu...@linaro.org> Cc: <deneen.t.d...@intel.com> Cc: <kernel-harden...@lists.openwall.com> Cc: <kris...@linux.intel.com> Cc: <linux_...@icloud.com> Cc: <will.dea...@arm.com> Cc: Andy Lutomirski <l...@kernel.org> Cc: Borislav Petkov <b...@alien8.de> Cc: Dave Hansen <dave.han...@linux.intel.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Nadav Amit <nadav.a...@gmail.com> Cc: Rafael J. Wysocki <r...@rjwysocki.net> Cc: Rik van Riel <r...@surriel.com> Cc: Thomas Gleixner <t...@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-16-na...@vmware.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/mm/pageattr.c | 4 ---- include/linux/mm.h | 18 ++++++------------ kernel/power/snapshot.c | 5 +++-- mm/page_alloc.c | 7 +++++-- 4 files changed, 14 insertions(+), 20 deletions(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 3574550192c6..daf4d645e537 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -2257,7 +2257,6 @@ int set_direct_map_default_noflush(struct page *page) return __set_pages_p(page, 1); } -#ifdef CONFIG_DEBUG_PAGEALLOC void __kernel_map_pages(struct page *page, int numpages, int enable) { if (PageHighMem(page)) @@ -2302,11 +2301,8 @@ bool kernel_page_present(struct page *page) pte = lookup_address((unsigned long)page_address(page), &level); return (pte_val(*pte) & _PAGE_PRESENT); } - #endif /* CONFIG_HIBERNATION */ -#endif /* CONFIG_DEBUG_PAGEALLOC */ - int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, unsigned numpages, unsigned long page_flags) { diff --git a/include/linux/mm.h b/include/linux/mm.h index 6b10c21630f5..083d7b4863ed 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2610,37 +2610,31 @@ static inline void kernel_poison_pages(struct page *page, int numpages, int enable) { } #endif -#ifdef CONFIG_DEBUG_PAGEALLOC extern bool _debug_pagealloc_enabled; -extern void __kernel_map_pages(struct page *page, int numpages, int enable); static inline bool debug_pagealloc_enabled(void) { - return _debug_pagealloc_enabled; + return IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) && _debug_pagealloc_enabled; } +#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP) +extern void __kernel_map_pages(struct page *page, int numpages, int enable); + static inline void kernel_map_pages(struct page *page, int numpages, int enable) { - if (!debug_pagealloc_enabled()) - return; - __kernel_map_pages(page, numpages, enable); } #ifdef CONFIG_HIBERNATION extern bool kernel_page_present(struct page *page); #endif /* CONFIG_HIBERNATION */ -#else /* CONFIG_DEBUG_PAGEALLOC */ +#else /* CONFIG_DEBUG_PAGEALLOC || CONFIG_ARCH_HAS_SET_DIRECT_MAP */ static inline void kernel_map_pages(struct page *page, int numpages, int enable) {} #ifdef CONFIG_HIBERNATION static inline bool kernel_page_present(struct page *page) { return true; } #endif /* CONFIG_HIBERNATION */ -static inline bool debug_pagealloc_enabled(void) -{ - return false; -} -#endif /* CONFIG_DEBUG_PAGEALLOC */ +#endif /* CONFIG_DEBUG_PAGEALLOC || CONFIG_ARCH_HAS_SET_DIRECT_MAP */ #ifdef __HAVE_ARCH_GATE_AREA extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm); diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index f08a1e4ee1d4..bc9558ab1e5b 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -1342,8 +1342,9 @@ static inline void do_copy_page(long *dst, long *src) * safe_copy_page - Copy a page in a safe way. * * Check if the page we are going to copy is marked as present in the kernel - * page tables (this always is the case if CONFIG_DEBUG_PAGEALLOC is not set - * and in that case kernel_page_present() always returns 'true'). + * page tables. This always is the case if CONFIG_DEBUG_PAGEALLOC or + * CONFIG_ARCH_HAS_SET_DIRECT_MAP is not set. In that case kernel_page_present() + * always returns 'true'. */ static void safe_copy_page(void *dst, struct page *s_page) { diff --git a/mm/page_alloc.c b/mm/page_alloc.c index c02cff1ed56e..59661106da16 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1144,7 +1144,9 @@ static __always_inline bool free_pages_prepare(struct page *page, } arch_free_page(page, order); kernel_poison_pages(page, 1 << order, 0); - kernel_map_pages(page, 1 << order, 0); + if (debug_pagealloc_enabled()) + kernel_map_pages(page, 1 << order, 0); + kasan_free_nondeferred_pages(page, order); return true; @@ -2014,7 +2016,8 @@ inline void post_alloc_hook(struct page *page, unsigned int order, set_page_refcounted(page); arch_alloc_page(page, order); - kernel_map_pages(page, 1 << order, 1); + if (debug_pagealloc_enabled()) + kernel_map_pages(page, 1 << order, 1); kasan_alloc_pages(page, order); kernel_poison_pages(page, 1 << order, 1); set_page_owner(page, order, gfp_flags);
