From patchwork Sun Nov 8 06:57:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Rapoport X-Patchwork-Id: 11889449 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9DF96697 for ; Sun, 8 Nov 2020 06:58:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FE1A20897 for ; Sun, 8 Nov 2020 06:58:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604818712; bh=590zK77IIK/GRU0iesSEW1g1nAaxcF2LlciXyBdNWeI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=C1QVtGIhzZ/w8GIgq2l51w4t4GQNmb2w4uqLk9crRvUTeA7gsGgzkI5BLlrmIo0+G Vz6XbYyIHxssTq8jPiKGgDoSDKqr2ye0Oal9izsi4PUPZxhvXKBpqJ4lWClfup+vC7 YL0Wlf4MLovpMI64+FBm2P4d/sUMMljclWxeaz2c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727457AbgKHG6Z (ORCPT ); Sun, 8 Nov 2020 01:58:25 -0500 Received: from mail.kernel.org ([198.145.29.99]:36370 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727452AbgKHG6Y (ORCPT ); Sun, 8 Nov 2020 01:58:24 -0500 Received: from aquarius.haifa.ibm.com (nesher1.haifa.il.ibm.com [195.110.40.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 48F71221FE; Sun, 8 Nov 2020 06:58:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604818703; bh=590zK77IIK/GRU0iesSEW1g1nAaxcF2LlciXyBdNWeI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S1Y5DBswnJRHvAhvlNmC6rXkkgTQxCugaaOkUKj5K5HgitkS61OQ0AYHixTLTqX7c AsmYAXrwvk4Jm9jm5qdYR9OjHM/USSXU7ddTb6jnhZOcumAy1eP1nZ3lLOSywTmN7K RZjefYfRwtk+pch6QAA8dQU6ZB0oI3gOHb8aaSxU= From: Mike Rapoport To: Andrew Morton Cc: Albert Ou , Andy Lutomirski , Benjamin Herrenschmidt , Borislav Petkov , Catalin Marinas , Christian Borntraeger , Christoph Lameter , "David S. Miller" , Dave Hansen , David Hildenbrand , David Rientjes , "Edgecombe, Rick P" , "H. Peter Anvin" , Heiko Carstens , Ingo Molnar , Joonsoo Kim , "Kirill A . Shutemov" , "Kirill A. Shutemov" , Len Brown , Michael Ellerman , Mike Rapoport , Mike Rapoport , Palmer Dabbelt , Paul Mackerras , Paul Walmsley , Pavel Machek , Pekka Enberg , Peter Zijlstra , "Rafael J. Wysocki" , Thomas Gleixner , Vasily Gorbik , Vlastimil Babka , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-pm@vger.kernel.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, x86@kernel.org Subject: [PATCH v5 1/5] mm: introduce debug_pagealloc_{map,unmap}_pages() helpers Date: Sun, 8 Nov 2020 08:57:54 +0200 Message-Id: <20201108065758.1815-2-rppt@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201108065758.1815-1-rppt@kernel.org> References: <20201108065758.1815-1-rppt@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Mike Rapoport When CONFIG_DEBUG_PAGEALLOC is enabled, it unmaps pages from the kernel direct mapping after free_pages(). The pages than need to be mapped back before they could be used. Theese mapping operations use __kernel_map_pages() guarded with with debug_pagealloc_enabled(). The only place that calls __kernel_map_pages() without checking whether DEBUG_PAGEALLOC is enabled is the hibernation code that presumes availability of this function when ARCH_HAS_SET_DIRECT_MAP is set. Still, on arm64, __kernel_map_pages() will bail out when DEBUG_PAGEALLOC is not enabled but set_direct_map_invalid_noflush() may render some pages not present in the direct map and hibernation code won't be able to save such pages. To make page allocation debugging and hibernation interaction more robust, the dependency on DEBUG_PAGEALLOC or ARCH_HAS_SET_DIRECT_MAP has to be made more explicit. Start with combining the guard condition and the call to __kernel_map_pages() into debug_pagealloc_map_pages() and debug_pagealloc_unmap_pages() functions to emphasize that __kernel_map_pages() should not be called without DEBUG_PAGEALLOC and use these new functions to map/unmap pages when page allocation debugging is enabled. Signed-off-by: Mike Rapoport Reviewed-by: David Hildenbrand Acked-by: Kirill A. Shutemov Acked-by: Vlastimil Babka --- include/linux/mm.h | 15 +++++++++++++++ mm/memory_hotplug.c | 3 +-- mm/page_alloc.c | 6 ++---- mm/slab.c | 16 +++++++--------- 4 files changed, 25 insertions(+), 15 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index ef360fe70aaf..bb8c70178f4e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2936,12 +2936,27 @@ kernel_map_pages(struct page *page, int numpages, int enable) { __kernel_map_pages(page, numpages, enable); } + +static inline void debug_pagealloc_map_pages(struct page *page, int numpages) +{ + if (debug_pagealloc_enabled_static()) + __kernel_map_pages(page, numpages, 1); +} + +static inline void debug_pagealloc_unmap_pages(struct page *page, int numpages) +{ + if (debug_pagealloc_enabled_static()) + __kernel_map_pages(page, numpages, 0); +} + #ifdef CONFIG_HIBERNATION extern bool kernel_page_present(struct page *page); #endif /* CONFIG_HIBERNATION */ #else /* CONFIG_DEBUG_PAGEALLOC || CONFIG_ARCH_HAS_SET_DIRECT_MAP */ static inline void kernel_map_pages(struct page *page, int numpages, int enable) {} +static inline void debug_pagealloc_map_pages(struct page *page, int numpages) {} +static inline void debug_pagealloc_unmap_pages(struct page *page, int numpages) {} #ifdef CONFIG_HIBERNATION static inline bool kernel_page_present(struct page *page) { return true; } #endif /* CONFIG_HIBERNATION */ diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index b44d4c7ba73b..f18f86ba2a68 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -614,8 +614,7 @@ void generic_online_page(struct page *page, unsigned int order) * so we should map it first. This is better than introducing a special * case in page freeing fast path. */ - if (debug_pagealloc_enabled_static()) - kernel_map_pages(page, 1 << order, 1); + debug_pagealloc_map_pages(page, 1 << order); __free_pages_core(page, order); totalram_pages_add(1UL << order); #ifdef CONFIG_HIGHMEM diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 23f5066bd4a5..db1bf70458d0 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1272,8 +1272,7 @@ static __always_inline bool free_pages_prepare(struct page *page, */ arch_free_page(page, order); - if (debug_pagealloc_enabled_static()) - kernel_map_pages(page, 1 << order, 0); + debug_pagealloc_unmap_pages(page, 1 << order); kasan_free_nondeferred_pages(page, order); @@ -2270,8 +2269,7 @@ inline void post_alloc_hook(struct page *page, unsigned int order, set_page_refcounted(page); arch_alloc_page(page, order); - if (debug_pagealloc_enabled_static()) - kernel_map_pages(page, 1 << order, 1); + debug_pagealloc_map_pages(page, 1 << order); kasan_alloc_pages(page, order); kernel_poison_pages(page, 1 << order, 1); set_page_owner(page, order, gfp_flags); diff --git a/mm/slab.c b/mm/slab.c index b1113561b98b..07317386e150 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -1428,21 +1428,19 @@ static bool is_debug_pagealloc_cache(struct kmem_cache *cachep) return false; } -#ifdef CONFIG_DEBUG_PAGEALLOC static void slab_kernel_map(struct kmem_cache *cachep, void *objp, int map) { if (!is_debug_pagealloc_cache(cachep)) return; - kernel_map_pages(virt_to_page(objp), cachep->size / PAGE_SIZE, map); + if (map) + debug_pagealloc_map_pages(virt_to_page(objp), + cachep->size / PAGE_SIZE); + else + debug_pagealloc_unmap_pages(virt_to_page(objp), + cachep->size / PAGE_SIZE); } -#else -static inline void slab_kernel_map(struct kmem_cache *cachep, void *objp, - int map) {} - -#endif - static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val) { int size = cachep->object_size; @@ -2062,7 +2060,7 @@ int __kmem_cache_create(struct kmem_cache *cachep, slab_flags_t flags) #if DEBUG /* - * If we're going to use the generic kernel_map_pages() + * If we're going to use the generic debug_pagealloc_map_pages() * poisoning, then it's going to smash the contents of * the redzone and userword anyhow, so switch them off. */