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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 C4E64C64E7A for ; Tue, 1 Dec 2020 11:52:14 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1007D2080A for ; Tue, 1 Dec 2020 11:52:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1007D2080A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 84E108D0003; Tue, 1 Dec 2020 06:52:12 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 824708D0001; Tue, 1 Dec 2020 06:52:12 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 738D98D0003; Tue, 1 Dec 2020 06:52:12 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0155.hostedemail.com [216.40.44.155]) by kanga.kvack.org (Postfix) with ESMTP id 5D8D48D0001 for ; Tue, 1 Dec 2020 06:52:12 -0500 (EST) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 2311E824999B for ; Tue, 1 Dec 2020 11:52:12 +0000 (UTC) X-FDA: 77544550104.08.night12_51076e0273aa Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin08.hostedemail.com (Postfix) with ESMTP id 09F341819E624 for ; Tue, 1 Dec 2020 11:52:12 +0000 (UTC) X-HE-Tag: night12_51076e0273aa X-Filterd-Recvd-Size: 6154 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Tue, 1 Dec 2020 11:52:11 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 69443ACC4; Tue, 1 Dec 2020 11:52:10 +0000 (UTC) From: Oscar Salvador To: david@redhat.com Cc: mhocko@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, vbabka@suse.cz, pasha.tatashin@soleen.com, Oscar Salvador Subject: [RFC PATCH v3 1/4] mm,memory_hotplug: Add mhp_supports_memmap_on_memory Date: Tue, 1 Dec 2020 12:51:55 +0100 Message-Id: <20201201115158.22638-2-osalvador@suse.de> X-Mailer: git-send-email 2.13.7 In-Reply-To: <20201201115158.22638-1-osalvador@suse.de> References: <20201201115158.22638-1-osalvador@suse.de> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: mhp_supports_memmap_on_memory is meant to be used by the caller prior to hot-adding memory in order to figure out whether it can enable MHP_MEMMAP_ON_MEMORY or not. Enabling MHP_MEMMAP_ON_MEMORY requires: - memmap_on_memory_enabled is set (by mhp_memmap_on_memory kernel boot option) - CONFIG_SPARSEMEM_VMEMMAP - architecture support for altmap - hot-added range spans a single memory block Note that mhp_memmap_on_memory kernel boot option will be added in a coming patch. At the moment, only three architectures support passing altmap when building the page tables: x86, POWERPC and ARM. Define an arch_support_memmap_on_memory function on those architectures that returns true, and define a __weak variant of it that will be used on the others. Signed-off-by: Oscar Salvador --- arch/arm64/mm/mmu.c | 5 +++++ arch/powerpc/mm/mem.c | 5 +++++ arch/x86/mm/init_64.c | 5 +++++ include/linux/memory_hotplug.h | 10 ++++++++++ mm/memory_hotplug.c | 24 ++++++++++++++++++++++++ 5 files changed, 49 insertions(+) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 30c6dd02e706..8a33ac97dcbb 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1454,6 +1454,11 @@ static bool inside_linear_region(u64 start, u64 size) (start + size - 1) <= __pa(PAGE_END - 1); } +bool arch_support_memmap_on_memory(void) +{ + return true; +} + int arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *params) { diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index 0694bdcce653..c5ef015c3189 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -181,6 +181,11 @@ void __ref arch_remove_memory(int nid, u64 start, u64 size, __remove_pages(start_pfn, nr_pages, altmap); arch_remove_linear_mapping(start, size); } + +bool arch_support_memmap_on_memory(void) +{ + return true; +} #endif #ifndef CONFIG_NEED_MULTIPLE_NODES diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index b5a3fa4033d3..ffb9d87c77e8 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -860,6 +860,11 @@ int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages, return ret; } +bool arch_support_memmap_on_memory(void) +{ + return true; +} + int arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *params) { diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 15acce5ab106..a54310abee79 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -70,6 +70,14 @@ typedef int __bitwise mhp_t; */ #define MEMHP_MERGE_RESOURCE ((__force mhp_t)BIT(0)) +/* + * We want memmap (struct page array) to be self contained. + * To do so, we will use the beginning of the hot-added range to build + * the page tables for the memmap array that describes the entire range. + * Only selected architectures support it with SPARSE_VMEMMAP. + */ +#define MHP_MEMMAP_ON_MEMORY ((__force mhp_t)BIT(1)) + /* * Extended parameters for memory hotplug: * altmap: alternative allocator for memmap array (optional) @@ -129,6 +137,7 @@ extern int try_online_node(int nid); extern int arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *params); +extern bool arch_support_memmap_on_memory(void); extern u64 max_mem_size; extern int memhp_online_type_from_str(const char *str); @@ -361,6 +370,7 @@ extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum); extern struct zone *zone_for_pfn_range(int online_type, int nid, unsigned start_pfn, unsigned long nr_pages); +extern bool mhp_supports_memmap_on_memory(unsigned long size); extern int arch_create_linear_mapping(int nid, u64 start, u64 size, struct mhp_params *params); void arch_remove_linear_mapping(u64 start, u64 size); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index a8cef4955907..e3c310225a60 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1011,6 +1011,20 @@ static int online_memory_block(struct memory_block *mem, void *arg) return device_online(&mem->dev); } +bool __weak arch_support_memmap_on_memory(void) +{ + return false; +} + +bool mhp_supports_memmap_on_memory(unsigned long size) +{ + if (!arch_support_memmap_on_memory() || + !IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP) || + size > memory_block_size_bytes()) + return false; + return true; +} + /* * NOTE: The caller must call lock_device_hotplug() to serialize hotplug * and online/offline operations (triggered e.g. by sysfs). @@ -1046,6 +1060,16 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) goto error; new_node = ret; + /* + * Return -EINVAL if caller specified MHP_MEMMAP_ON_MEMORY and we do + * not support it. + */ + if ((mhp_flags & MHP_MEMMAP_ON_MEMORY) && + !mhp_supports_memmap_on_memory(size)) { + ret = -EINVAL; + goto error; + } + /* call arch's memory hotadd */ ret = arch_add_memory(nid, start, size, ¶ms); if (ret < 0) -- 2.26.2