From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 361AEC4363A for ; Mon, 26 Oct 2020 11:55:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D3E43223AB for ; Mon, 26 Oct 2020 11:54:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603713299; bh=JL5L+tjAdTtgTIzF1IyLb8dhJjCHzTjL2OJ0c6FU4w4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=hT69sONGUkZVysMjWYcrznma/7OheA85YSqAsNJHb07GOLiYg3O97KJLEB7Pl9Np5 Uub3vBUM5uLAO5ZLMVf4W1le0W+NQSTo1G2NMbh+EGlVUFBCi+80FkoaGSp2+ijjl5 YcAcn8C3GcopBM6mGXOgY3Zu56ruCEKsx9E9O9ME= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1774130AbgJZLy7 (ORCPT ); Mon, 26 Oct 2020 07:54:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:39154 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2441155AbgJZLy6 (ORCPT ); Mon, 26 Oct 2020 07:54:58 -0400 Received: from kernel.org (unknown [87.70.96.83]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5891822265; Mon, 26 Oct 2020 11:54:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603713297; bh=JL5L+tjAdTtgTIzF1IyLb8dhJjCHzTjL2OJ0c6FU4w4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=beAfxtxVzIWG7/PQSB9oT8HrWkddsR0PDdaGNijlEC3AuMvcZUXxJY9R8puB77jj0 rPlZw+P1uGuAIqPmVzWmAkw1wLYd5tKrK+EpdZCOH48DMhCjDSmOkzAPgP4u1ZC3/i Sc+DoqTEeolhEbCvCJLclcbZXLgz0JV5qw710moE= Date: Mon, 26 Oct 2020 13:54:43 +0200 From: Mike Rapoport To: David Hildenbrand Cc: Andrew Morton , Albert Ou , Andy Lutomirski , Benjamin Herrenschmidt , Borislav Petkov , Catalin Marinas , Christian Borntraeger , Christoph Lameter , "David S. Miller" , Dave Hansen , David Rientjes , "Edgecombe, Rick P" , "H. Peter Anvin" , Heiko Carstens , Ingo Molnar , Joonsoo Kim , "Kirill A. Shutemov" , Len Brown , Michael Ellerman , Mike Rapoport , Palmer Dabbelt , Paul Mackerras , Paul Walmsley , Pavel Machek , Pekka Enberg , Peter Zijlstra , "Rafael J. Wysocki" , Thomas Gleixner , Vasily Gorbik , 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: Re: [PATCH 1/4] mm: introduce debug_pagealloc_map_pages() helper Message-ID: <20201026115443.GF1154158@kernel.org> References: <20201025101555.3057-1-rppt@kernel.org> <20201025101555.3057-2-rppt@kernel.org> <8720c067-7dc5-2b02-918b-e54dd642bfd6@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8720c067-7dc5-2b02-918b-e54dd642bfd6@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Mon, Oct 26, 2020 at 12:05:13PM +0100, David Hildenbrand wrote: > On 25.10.20 11:15, Mike Rapoport wrote: > > 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 a single debug_pagealloc_map_pages() > > function to emphasize that __kernel_map_pages() should not be called > > without DEBUG_PAGEALLOC and use this new function to map/unmap pages > > when page allocation debug is enabled. > > > > As the only remaining user of kernel_map_pages() is the hibernation > > code, mode that function into kernel/power/snapshot.c closer to a > > caller. > > s/mode/move/ > > > > > Signed-off-by: Mike Rapoport --- > > include/linux/mm.h | 16 +++++++--------- kernel/power/snapshot.c > > | 11 +++++++++++ mm/memory_hotplug.c | 3 +-- mm/page_alloc.c > > | 6 ++---- mm/slab.c | 8 +++----- 5 files changed, 24 > > insertions(+), 20 deletions(-) > > > > diff --git a/include/linux/mm.h b/include/linux/mm.h index > > ef360fe70aaf..14e397f3752c 100644 --- a/include/linux/mm.h +++ > > b/include/linux/mm.h @@ -2927,21 +2927,19 @@ static inline bool > > debug_pagealloc_enabled_static(void) #if > > defined(CONFIG_DEBUG_PAGEALLOC) || > > defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP) extern void > > __kernel_map_pages(struct page *page, int numpages, int enable); > > > > -/* - * When called in DEBUG_PAGEALLOC context, the call should most > > likely be - * guarded by debug_pagealloc_enabled() or > > debug_pagealloc_enabled_static() - */ -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, int enable) { - __kernel_map_pages(page, numpages, > > enable); + if (debug_pagealloc_enabled_static()) + > > __kernel_map_pages(page, numpages, enable); } + #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, int enable) {} #ifdef > > CONFIG_HIBERNATION static inline bool kernel_page_present(struct page > > *page) { return true; } #endif /* CONFIG_HIBERNATION */ diff --git > > a/kernel/power/snapshot.c b/kernel/power/snapshot.c index > > 46b1804c1ddf..fa499466f645 100644 --- a/kernel/power/snapshot.c +++ > > b/kernel/power/snapshot.c @@ -76,6 +76,17 @@ static inline void > > hibernate_restore_protect_page(void *page_address) {} static inline > > void hibernate_restore_unprotect_page(void *page_address) {} #endif > > /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */ > > > > +#if defined(CONFIG_DEBUG_PAGEALLOC) || > > defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP) +static inline void > > +kernel_map_pages(struct page *page, int numpages, int enable) +{ + > > __kernel_map_pages(page, numpages, enable); +} +#else +static inline > > void +kernel_map_pages(struct page *page, int numpages, int enable) > > {} +#endif + > > That change should go into a separate patch. Hmm, I beleive you refer to moving kernel_map_pages() to snapshot.c, right? > For the debug_pagealloc_map_pages() parts > > Reviewed-by: David Hildenbrand Thanks! > -- > Thanks, > > David / dhildenb > -- Sincerely yours, Mike. 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b=XZ7ByWGsp1YlOKK34zZIDPIEHT ngIUasaeFVGVIY7YDJKIoByvj8ECqqs2CI/OCi/EaacCZcgQ8HZ4ZICctJz+zU3ziziKnZCA1aRDv HpsefrE+nWm902fIsYuW51VrzVupsydzBn3GD4xZtS79hZe2kp3MnOBgj27PIl+w6dWrCzugoBFga VwBTVOe4DLSIe1LXZIaO/vO+jaCZyaGzSV7BADAzOjj1YPWEalxEwxv4YEv3AHQkcUpdp6VEMLxe7 zKpoa6foEZuL5rlfjNDvV0FtiODq6HWyZZn103gjK9OFgIT48h/seFSQW1b64W47ApEEYebGQkDBU YV8Q4OAQ==; Received: from mail.kernel.org ([198.145.29.99]) by casper.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kX15a-00013v-5D; Mon, 26 Oct 2020 11:55:05 +0000 Received: from kernel.org (unknown [87.70.96.83]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5891822265; Mon, 26 Oct 2020 11:54:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603713297; bh=JL5L+tjAdTtgTIzF1IyLb8dhJjCHzTjL2OJ0c6FU4w4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=beAfxtxVzIWG7/PQSB9oT8HrWkddsR0PDdaGNijlEC3AuMvcZUXxJY9R8puB77jj0 rPlZw+P1uGuAIqPmVzWmAkw1wLYd5tKrK+EpdZCOH48DMhCjDSmOkzAPgP4u1ZC3/i Sc+DoqTEeolhEbCvCJLclcbZXLgz0JV5qw710moE= Date: Mon, 26 Oct 2020 13:54:43 +0200 From: Mike Rapoport To: David Hildenbrand Subject: Re: [PATCH 1/4] mm: introduce debug_pagealloc_map_pages() helper Message-ID: <20201026115443.GF1154158@kernel.org> References: <20201025101555.3057-1-rppt@kernel.org> <20201025101555.3057-2-rppt@kernel.org> <8720c067-7dc5-2b02-918b-e54dd642bfd6@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <8720c067-7dc5-2b02-918b-e54dd642bfd6@redhat.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201026_115502_855513_778CFEA2 X-CRM114-Status: GOOD ( 36.09 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Zijlstra , Benjamin Herrenschmidt , Dave Hansen , linux-mm@kvack.org, Paul Mackerras , Pavel Machek , "H. Peter Anvin" , sparclinux@vger.kernel.org, Christoph Lameter , Will Deacon , linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, Michael Ellerman , x86@kernel.org, Mike Rapoport , Christian Borntraeger , Ingo Molnar , Catalin Marinas , Len Brown , Albert Ou , Vasily Gorbik , linux-pm@vger.kernel.org, Heiko Carstens , David Rientjes , Borislav Petkov , Andy Lutomirski , Paul Walmsley , "Kirill A. Shutemov" , Thomas Gleixner , Joonsoo Kim , linux-arm-kernel@lists.infradead.org, "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Pekka Enberg , Palmer Dabbelt , Andrew Morton , "Edgecombe, Rick P" , linuxppc-dev@lists.ozlabs.org, "David S. Miller" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Mon, Oct 26, 2020 at 12:05:13PM +0100, David Hildenbrand wrote: > On 25.10.20 11:15, Mike Rapoport wrote: > > 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 a single debug_pagealloc_map_pages() > > function to emphasize that __kernel_map_pages() should not be called > > without DEBUG_PAGEALLOC and use this new function to map/unmap pages > > when page allocation debug is enabled. > > > > As the only remaining user of kernel_map_pages() is the hibernation > > code, mode that function into kernel/power/snapshot.c closer to a > > caller. > > s/mode/move/ > > > > > Signed-off-by: Mike Rapoport --- > > include/linux/mm.h | 16 +++++++--------- kernel/power/snapshot.c > > | 11 +++++++++++ mm/memory_hotplug.c | 3 +-- mm/page_alloc.c > > | 6 ++---- mm/slab.c | 8 +++----- 5 files changed, 24 > > insertions(+), 20 deletions(-) > > > > diff --git a/include/linux/mm.h b/include/linux/mm.h index > > ef360fe70aaf..14e397f3752c 100644 --- a/include/linux/mm.h +++ > > b/include/linux/mm.h @@ -2927,21 +2927,19 @@ static inline bool > > debug_pagealloc_enabled_static(void) #if > > defined(CONFIG_DEBUG_PAGEALLOC) || > > defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP) extern void > > __kernel_map_pages(struct page *page, int numpages, int enable); > > > > -/* - * When called in DEBUG_PAGEALLOC context, the call should most > > likely be - * guarded by debug_pagealloc_enabled() or > > debug_pagealloc_enabled_static() - */ -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, int enable) { - __kernel_map_pages(page, numpages, > > enable); + if (debug_pagealloc_enabled_static()) + > > __kernel_map_pages(page, numpages, enable); } + #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, int enable) {} #ifdef > > CONFIG_HIBERNATION static inline bool kernel_page_present(struct page > > *page) { return true; } #endif /* CONFIG_HIBERNATION */ diff --git > > a/kernel/power/snapshot.c b/kernel/power/snapshot.c index > > 46b1804c1ddf..fa499466f645 100644 --- a/kernel/power/snapshot.c +++ > > b/kernel/power/snapshot.c @@ -76,6 +76,17 @@ static inline void > > hibernate_restore_protect_page(void *page_address) {} static inline > > void hibernate_restore_unprotect_page(void *page_address) {} #endif > > /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */ > > > > +#if defined(CONFIG_DEBUG_PAGEALLOC) || > > defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP) +static inline void > > +kernel_map_pages(struct page *page, int numpages, int enable) +{ + > > __kernel_map_pages(page, numpages, enable); +} +#else +static inline > > void +kernel_map_pages(struct page *page, int numpages, int enable) > > {} +#endif + > > That change should go into a separate patch. Hmm, I beleive you refer to moving kernel_map_pages() to snapshot.c, right? > For the debug_pagealloc_map_pages() parts > > Reviewed-by: David Hildenbrand Thanks! > -- > Thanks, > > David / dhildenb > -- Sincerely yours, Mike. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4ADCEC4363A for ; Mon, 26 Oct 2020 11:58:56 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3B22222263 for ; Mon, 26 Oct 2020 11:58:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="beAfxtxV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B22222263 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4CKYJr18t8zDqMT for ; Mon, 26 Oct 2020 22:58:52 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=rppt@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=default header.b=beAfxtxV; dkim-atps=neutral Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4CKYDP1fdczDqMd for ; Mon, 26 Oct 2020 22:55:01 +1100 (AEDT) Received: from kernel.org (unknown [87.70.96.83]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5891822265; Mon, 26 Oct 2020 11:54:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603713297; bh=JL5L+tjAdTtgTIzF1IyLb8dhJjCHzTjL2OJ0c6FU4w4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=beAfxtxVzIWG7/PQSB9oT8HrWkddsR0PDdaGNijlEC3AuMvcZUXxJY9R8puB77jj0 rPlZw+P1uGuAIqPmVzWmAkw1wLYd5tKrK+EpdZCOH48DMhCjDSmOkzAPgP4u1ZC3/i Sc+DoqTEeolhEbCvCJLclcbZXLgz0JV5qw710moE= Date: Mon, 26 Oct 2020 13:54:43 +0200 From: Mike Rapoport To: David Hildenbrand Subject: Re: [PATCH 1/4] mm: introduce debug_pagealloc_map_pages() helper Message-ID: <20201026115443.GF1154158@kernel.org> References: <20201025101555.3057-1-rppt@kernel.org> <20201025101555.3057-2-rppt@kernel.org> <8720c067-7dc5-2b02-918b-e54dd642bfd6@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8720c067-7dc5-2b02-918b-e54dd642bfd6@redhat.com> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Zijlstra , Dave Hansen , linux-mm@kvack.org, Paul Mackerras , Pavel Machek , "H. Peter Anvin" , sparclinux@vger.kernel.org, Christoph Lameter , Will Deacon , linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, x86@kernel.org, Mike Rapoport , Christian Borntraeger , Ingo Molnar , Catalin Marinas , Len Brown , Albert Ou , Vasily Gorbik , linux-pm@vger.kernel.org, Heiko Carstens , David Rientjes , Borislav Petkov , Andy Lutomirski , Paul Walmsley , "Kirill A. Shutemov" , Thomas Gleixner , Joonsoo Kim , linux-arm-kernel@lists.infradead.org, "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Pekka Enberg , Palmer Dabbelt , Andrew Morton , "Edgecombe, Rick P" , linuxppc-dev@lists.ozlabs.org, "David S. Miller" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Oct 26, 2020 at 12:05:13PM +0100, David Hildenbrand wrote: > On 25.10.20 11:15, Mike Rapoport wrote: > > 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 a single debug_pagealloc_map_pages() > > function to emphasize that __kernel_map_pages() should not be called > > without DEBUG_PAGEALLOC and use this new function to map/unmap pages > > when page allocation debug is enabled. > > > > As the only remaining user of kernel_map_pages() is the hibernation > > code, mode that function into kernel/power/snapshot.c closer to a > > caller. > > s/mode/move/ > > > > > Signed-off-by: Mike Rapoport --- > > include/linux/mm.h | 16 +++++++--------- kernel/power/snapshot.c > > | 11 +++++++++++ mm/memory_hotplug.c | 3 +-- mm/page_alloc.c > > | 6 ++---- mm/slab.c | 8 +++----- 5 files changed, 24 > > insertions(+), 20 deletions(-) > > > > diff --git a/include/linux/mm.h b/include/linux/mm.h index > > ef360fe70aaf..14e397f3752c 100644 --- a/include/linux/mm.h +++ > > b/include/linux/mm.h @@ -2927,21 +2927,19 @@ static inline bool > > debug_pagealloc_enabled_static(void) #if > > defined(CONFIG_DEBUG_PAGEALLOC) || > > defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP) extern void > > __kernel_map_pages(struct page *page, int numpages, int enable); > > > > -/* - * When called in DEBUG_PAGEALLOC context, the call should most > > likely be - * guarded by debug_pagealloc_enabled() or > > debug_pagealloc_enabled_static() - */ -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, int enable) { - __kernel_map_pages(page, numpages, > > enable); + if (debug_pagealloc_enabled_static()) + > > __kernel_map_pages(page, numpages, enable); } + #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, int enable) {} #ifdef > > CONFIG_HIBERNATION static inline bool kernel_page_present(struct page > > *page) { return true; } #endif /* CONFIG_HIBERNATION */ diff --git > > a/kernel/power/snapshot.c b/kernel/power/snapshot.c index > > 46b1804c1ddf..fa499466f645 100644 --- a/kernel/power/snapshot.c +++ > > b/kernel/power/snapshot.c @@ -76,6 +76,17 @@ static inline void > > hibernate_restore_protect_page(void *page_address) {} static inline > > void hibernate_restore_unprotect_page(void *page_address) {} #endif > > /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */ > > > > +#if defined(CONFIG_DEBUG_PAGEALLOC) || > > defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP) +static inline void > > +kernel_map_pages(struct page *page, int numpages, int enable) +{ + > > __kernel_map_pages(page, numpages, enable); +} +#else +static inline > > void +kernel_map_pages(struct page *page, int numpages, int enable) > > {} +#endif + > > That change should go into a separate patch. Hmm, I beleive you refer to moving kernel_map_pages() to snapshot.c, right? > For the debug_pagealloc_map_pages() parts > > Reviewed-by: David Hildenbrand Thanks! > -- > Thanks, > > David / dhildenb > -- Sincerely yours, Mike. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Rapoport Date: Mon, 26 Oct 2020 11:54:43 +0000 Subject: Re: [PATCH 1/4] mm: introduce debug_pagealloc_map_pages() helper Message-Id: <20201026115443.GF1154158@kernel.org> List-Id: References: <20201025101555.3057-1-rppt@kernel.org> <20201025101555.3057-2-rppt@kernel.org> <8720c067-7dc5-2b02-918b-e54dd642bfd6@redhat.com> In-Reply-To: <8720c067-7dc5-2b02-918b-e54dd642bfd6@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Hildenbrand Cc: Peter Zijlstra , Benjamin Herrenschmidt , Dave Hansen , linux-mm@kvack.org, Paul Mackerras , Pavel Machek , "H. Peter Anvin" , sparclinux@vger.kernel.org, Christoph Lameter , Will Deacon , linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, Michael Ellerman , x86@kernel.org, Mike Rapoport , Christian Borntraeger , Ingo Molnar , Catalin Marinas , Len Brown , Albert Ou , Vasily Gorbik , linux-pm@vger.kernel.org, Heiko Carstens , David Rientjes , Borislav Petkov , Andy Lutomirski , Paul Walmsley , "Kirill A. Shutemov" , Thomas Gleixner , Joonsoo Kim , linux-arm-kernel@lists.infradead.org, "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Pekka Enberg , Palmer Dabbelt , Andrew Morton , "Edgecombe, Rick P" , linuxppc-dev@lists.ozlabs.org, "David S. Miller" On Mon, Oct 26, 2020 at 12:05:13PM +0100, David Hildenbrand wrote: > On 25.10.20 11:15, Mike Rapoport wrote: > > 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 a single debug_pagealloc_map_pages() > > function to emphasize that __kernel_map_pages() should not be called > > without DEBUG_PAGEALLOC and use this new function to map/unmap pages > > when page allocation debug is enabled. > > > > As the only remaining user of kernel_map_pages() is the hibernation > > code, mode that function into kernel/power/snapshot.c closer to a > > caller. > > s/mode/move/ > > > > > Signed-off-by: Mike Rapoport --- > > include/linux/mm.h | 16 +++++++--------- kernel/power/snapshot.c > > | 11 +++++++++++ mm/memory_hotplug.c | 3 +-- mm/page_alloc.c > > | 6 ++---- mm/slab.c | 8 +++----- 5 files changed, 24 > > insertions(+), 20 deletions(-) > > > > diff --git a/include/linux/mm.h b/include/linux/mm.h index > > ef360fe70aaf..14e397f3752c 100644 --- a/include/linux/mm.h +++ > > b/include/linux/mm.h @@ -2927,21 +2927,19 @@ static inline bool > > debug_pagealloc_enabled_static(void) #if > > defined(CONFIG_DEBUG_PAGEALLOC) || > > defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP) extern void > > __kernel_map_pages(struct page *page, int numpages, int enable); > > > > -/* - * When called in DEBUG_PAGEALLOC context, the call should most > > likely be - * guarded by debug_pagealloc_enabled() or > > debug_pagealloc_enabled_static() - */ -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, int enable) { - __kernel_map_pages(page, numpages, > > enable); + if (debug_pagealloc_enabled_static()) + > > __kernel_map_pages(page, numpages, enable); } + #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, int enable) {} #ifdef > > CONFIG_HIBERNATION static inline bool kernel_page_present(struct page > > *page) { return true; } #endif /* CONFIG_HIBERNATION */ diff --git > > a/kernel/power/snapshot.c b/kernel/power/snapshot.c index > > 46b1804c1ddf..fa499466f645 100644 --- a/kernel/power/snapshot.c +++ > > b/kernel/power/snapshot.c @@ -76,6 +76,17 @@ static inline void > > hibernate_restore_protect_page(void *page_address) {} static inline > > void hibernate_restore_unprotect_page(void *page_address) {} #endif > > /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */ > > > > +#if defined(CONFIG_DEBUG_PAGEALLOC) || > > defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP) +static inline void > > +kernel_map_pages(struct page *page, int numpages, int enable) +{ + > > __kernel_map_pages(page, numpages, enable); +} +#else +static inline > > void +kernel_map_pages(struct page *page, int numpages, int enable) > > {} +#endif + > > That change should go into a separate patch. Hmm, I beleive you refer to moving kernel_map_pages() to snapshot.c, right? > For the debug_pagealloc_map_pages() parts > > Reviewed-by: David Hildenbrand Thanks! > -- > Thanks, > > David / dhildenb > -- Sincerely yours, Mike. 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b=XZ7ByWGsp1YlOKK34zZIDPIEHT ngIUasaeFVGVIY7YDJKIoByvj8ECqqs2CI/OCi/EaacCZcgQ8HZ4ZICctJz+zU3ziziKnZCA1aRDv HpsefrE+nWm902fIsYuW51VrzVupsydzBn3GD4xZtS79hZe2kp3MnOBgj27PIl+w6dWrCzugoBFga VwBTVOe4DLSIe1LXZIaO/vO+jaCZyaGzSV7BADAzOjj1YPWEalxEwxv4YEv3AHQkcUpdp6VEMLxe7 zKpoa6foEZuL5rlfjNDvV0FtiODq6HWyZZn103gjK9OFgIT48h/seFSQW1b64W47ApEEYebGQkDBU YV8Q4OAQ==; Received: from mail.kernel.org ([198.145.29.99]) by casper.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kX15a-00013v-5D; Mon, 26 Oct 2020 11:55:05 +0000 Received: from kernel.org (unknown [87.70.96.83]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5891822265; Mon, 26 Oct 2020 11:54:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603713297; bh=JL5L+tjAdTtgTIzF1IyLb8dhJjCHzTjL2OJ0c6FU4w4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=beAfxtxVzIWG7/PQSB9oT8HrWkddsR0PDdaGNijlEC3AuMvcZUXxJY9R8puB77jj0 rPlZw+P1uGuAIqPmVzWmAkw1wLYd5tKrK+EpdZCOH48DMhCjDSmOkzAPgP4u1ZC3/i Sc+DoqTEeolhEbCvCJLclcbZXLgz0JV5qw710moE= Date: Mon, 26 Oct 2020 13:54:43 +0200 From: Mike Rapoport To: David Hildenbrand Subject: Re: [PATCH 1/4] mm: introduce debug_pagealloc_map_pages() helper Message-ID: <20201026115443.GF1154158@kernel.org> References: <20201025101555.3057-1-rppt@kernel.org> <20201025101555.3057-2-rppt@kernel.org> <8720c067-7dc5-2b02-918b-e54dd642bfd6@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <8720c067-7dc5-2b02-918b-e54dd642bfd6@redhat.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201026_115502_855513_778CFEA2 X-CRM114-Status: GOOD ( 36.09 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Zijlstra , Benjamin Herrenschmidt , Dave Hansen , linux-mm@kvack.org, Paul Mackerras , Pavel Machek , "H. Peter Anvin" , sparclinux@vger.kernel.org, Christoph Lameter , Will Deacon , linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, Michael Ellerman , x86@kernel.org, Mike Rapoport , Christian Borntraeger , Ingo Molnar , Catalin Marinas , Len Brown , Albert Ou , Vasily Gorbik , linux-pm@vger.kernel.org, Heiko Carstens , David Rientjes , Borislav Petkov , Andy Lutomirski , Paul Walmsley , "Kirill A. Shutemov" , Thomas Gleixner , Joonsoo Kim , linux-arm-kernel@lists.infradead.org, "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Pekka Enberg , Palmer Dabbelt , Andrew Morton , "Edgecombe, Rick P" , linuxppc-dev@lists.ozlabs.org, "David S. Miller" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Oct 26, 2020 at 12:05:13PM +0100, David Hildenbrand wrote: > On 25.10.20 11:15, Mike Rapoport wrote: > > 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 a single debug_pagealloc_map_pages() > > function to emphasize that __kernel_map_pages() should not be called > > without DEBUG_PAGEALLOC and use this new function to map/unmap pages > > when page allocation debug is enabled. > > > > As the only remaining user of kernel_map_pages() is the hibernation > > code, mode that function into kernel/power/snapshot.c closer to a > > caller. > > s/mode/move/ > > > > > Signed-off-by: Mike Rapoport --- > > include/linux/mm.h | 16 +++++++--------- kernel/power/snapshot.c > > | 11 +++++++++++ mm/memory_hotplug.c | 3 +-- mm/page_alloc.c > > | 6 ++---- mm/slab.c | 8 +++----- 5 files changed, 24 > > insertions(+), 20 deletions(-) > > > > diff --git a/include/linux/mm.h b/include/linux/mm.h index > > ef360fe70aaf..14e397f3752c 100644 --- a/include/linux/mm.h +++ > > b/include/linux/mm.h @@ -2927,21 +2927,19 @@ static inline bool > > debug_pagealloc_enabled_static(void) #if > > defined(CONFIG_DEBUG_PAGEALLOC) || > > defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP) extern void > > __kernel_map_pages(struct page *page, int numpages, int enable); > > > > -/* - * When called in DEBUG_PAGEALLOC context, the call should most > > likely be - * guarded by debug_pagealloc_enabled() or > > debug_pagealloc_enabled_static() - */ -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, int enable) { - __kernel_map_pages(page, numpages, > > enable); + if (debug_pagealloc_enabled_static()) + > > __kernel_map_pages(page, numpages, enable); } + #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, int enable) {} #ifdef > > CONFIG_HIBERNATION static inline bool kernel_page_present(struct page > > *page) { return true; } #endif /* CONFIG_HIBERNATION */ diff --git > > a/kernel/power/snapshot.c b/kernel/power/snapshot.c index > > 46b1804c1ddf..fa499466f645 100644 --- a/kernel/power/snapshot.c +++ > > b/kernel/power/snapshot.c @@ -76,6 +76,17 @@ static inline void > > hibernate_restore_protect_page(void *page_address) {} static inline > > void hibernate_restore_unprotect_page(void *page_address) {} #endif > > /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */ > > > > +#if defined(CONFIG_DEBUG_PAGEALLOC) || > > defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP) +static inline void > > +kernel_map_pages(struct page *page, int numpages, int enable) +{ + > > __kernel_map_pages(page, numpages, enable); +} +#else +static inline > > void +kernel_map_pages(struct page *page, int numpages, int enable) > > {} +#endif + > > That change should go into a separate patch. Hmm, I beleive you refer to moving kernel_map_pages() to snapshot.c, right? > For the debug_pagealloc_map_pages() parts > > Reviewed-by: David Hildenbrand Thanks! > -- > Thanks, > > David / dhildenb > -- Sincerely yours, Mike. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel