From patchwork Thu Jul 20 07:14:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 13319902 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A11BAEB64DC for ; Thu, 20 Jul 2023 07:14:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229961AbjGTHOf (ORCPT ); Thu, 20 Jul 2023 03:14:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47470 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229902AbjGTHOc (ORCPT ); Thu, 20 Jul 2023 03:14:32 -0400 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3306A2121; Thu, 20 Jul 2023 00:14:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689837271; x=1721373271; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=Xs/UipfGvLxTajC0Rm3FutNPJhFtxOc43qHe7lqOerY=; b=kpmCCJmOWxKQzgANJGlyLS2yNsn+8Tz6qafqPRQ6FwlsIOCg3QD93p6E 9N2FYCuShB/vjPsx2UwAUE1+5C6G5B3oyabceb4LB0wES9CoGS5RB1SF3 7nI/yKnzPumQb6DnMdF90LbAFcoelD1BhH6gC9xizqijRjKVvLII/GlwI WHiroOuje6LHXRauUV1WvElvR3FyDjyo/WizOqW83FOHQr+5hXOtaGr2b uESCE0QDKUeOC1k3CQ0cyZ5OP+YHXdxtkCM67QK+belbp0h5pYNmXAxMZ aoUE2Kdb9Q5AVxlj7EvQsiokAShciecCw2QnXTbEfwFE97MieKtoOad5T g==; X-IronPort-AV: E=McAfee;i="6600,9927,10776"; a="430423994" X-IronPort-AV: E=Sophos;i="6.01,218,1684825200"; d="scan'208";a="430423994" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jul 2023 00:14:29 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10776"; a="794334963" X-IronPort-AV: E=Sophos;i="6.01,218,1684825200"; d="scan'208";a="794334963" Received: from mfgalan-mobl1.amr.corp.intel.com (HELO [192.168.1.200]) ([10.213.172.204]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jul 2023 00:14:29 -0700 From: Vishal Verma Date: Thu, 20 Jul 2023 01:14:22 -0600 Subject: [PATCH v2 1/3] mm/memory_hotplug: Export symbol mhp_supports_memmap_on_memory() MIME-Version: 1.0 Message-Id: <20230720-vv-kmem_memmap-v2-1-88bdaab34993@intel.com> References: <20230720-vv-kmem_memmap-v2-0-88bdaab34993@intel.com> In-Reply-To: <20230720-vv-kmem_memmap-v2-0-88bdaab34993@intel.com> To: Andrew Morton , David Hildenbrand , Oscar Salvador , Dan Williams , Dave Jiang Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, Huang Ying , Dave Hansen , "Aneesh Kumar K.V" , Jonathan Cameron , Jeff Moyer , Vishal Verma X-Mailer: b4 0.12.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=1866; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=Xs/UipfGvLxTajC0Rm3FutNPJhFtxOc43qHe7lqOerY=; b=owGbwMvMwCXGf25diOft7jLG02pJDCk77l05/3bRlO0HRGt3l/1Y+qNe3Wzlkv+flP2CnC4d+ 27Ly+NwoaOUhUGMi0FWTJHl756PjMfktufzBCY4wsxhZQIZwsDFKQATub2SkaFxwmNetUNtifs0 jJyK+GWuXObfuVZ0f0vNtFhNozqZlQyMDPfzRPRPe0x/19WUOsF+g+UCnWtP3jSX3VjY1NJxc8p rIzYA X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org In preparation for dax drivers, which can be built as modules, to use this interface, export it with EXPORT_SYMBOL_GPL(). Add a #else case for the symbol for builds without CONFIG_MEMORY_HOTPLUG. Cc: Andrew Morton Cc: David Hildenbrand Cc: Oscar Salvador Cc: Dan Williams Cc: Dave Jiang Cc: Dave Hansen Cc: Huang Ying Reviewed-by: David Hildenbrand Signed-off-by: Vishal Verma --- include/linux/memory_hotplug.h | 5 +++++ mm/memory_hotplug.c | 1 + 2 files changed, 6 insertions(+) diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 013c69753c91..fc5da07ad011 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -355,6 +355,11 @@ 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); extern bool mhp_supports_memmap_on_memory(unsigned long size); +#else +static inline bool mhp_supports_memmap_on_memory(unsigned long size) +{ + return false; +} #endif /* CONFIG_MEMORY_HOTPLUG */ #endif /* __LINUX_MEMORY_HOTPLUG_H */ diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 3f231cf1b410..e9bcacbcbae2 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1284,6 +1284,7 @@ bool mhp_supports_memmap_on_memory(unsigned long size) IS_ALIGNED(vmemmap_size, PMD_SIZE) && IS_ALIGNED(remaining_size, (pageblock_nr_pages << PAGE_SHIFT)); } +EXPORT_SYMBOL_GPL(mhp_supports_memmap_on_memory); /* * NOTE: The caller must call lock_device_hotplug() to serialize hotplug From patchwork Thu Jul 20 07:14:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 13319904 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B968EB64DA for ; Thu, 20 Jul 2023 07:14:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229832AbjGTHOf (ORCPT ); Thu, 20 Jul 2023 03:14:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229816AbjGTHOe (ORCPT ); Thu, 20 Jul 2023 03:14:34 -0400 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D225F19A7; Thu, 20 Jul 2023 00:14:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689837272; x=1721373272; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=k4XpCfq0ZxU/xUvbPf7nQuvL2vPIJUVSa8ob3/AsbKg=; b=jzJ4IC5SMO+sGD4tHjMrpU2G+0CRQWeMfihltFO39iyj8QvbnmzmCiXu cHvmVwQJ2ZNFX+NyxRK70qTEu4r81ViXaZ+roDLbkanaHAWPDVp1uQjk2 npdW7RQzqeR6qN0RF3uims4hUBManXSgUI/aseAf7TOCu6lK1rllgB0/I FjJy8zYqp5K2Z+7g5qWcOtQXcdbJypOkqqm2p+4GdnTwKppzHyTkBPrOf ZZLGMnbW+12+Gj5ADrj7RPolnGQU1URAFOAXzperbmf73iREnbt5AFOa5 rHy8b2/6/DGmrIlAtw72w8xZn+AuyQLOae1+ayxbXhXIBNOLD4UgVkyUc Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10776"; a="430424007" X-IronPort-AV: E=Sophos;i="6.01,218,1684825200"; d="scan'208";a="430424007" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jul 2023 00:14:31 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10776"; a="794334967" X-IronPort-AV: E=Sophos;i="6.01,218,1684825200"; d="scan'208";a="794334967" Received: from mfgalan-mobl1.amr.corp.intel.com (HELO [192.168.1.200]) ([10.213.172.204]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jul 2023 00:14:29 -0700 From: Vishal Verma Date: Thu, 20 Jul 2023 01:14:23 -0600 Subject: [PATCH v2 2/3] mm/memory_hotplug: split memmap_on_memory requests across memblocks MIME-Version: 1.0 Message-Id: <20230720-vv-kmem_memmap-v2-2-88bdaab34993@intel.com> References: <20230720-vv-kmem_memmap-v2-0-88bdaab34993@intel.com> In-Reply-To: <20230720-vv-kmem_memmap-v2-0-88bdaab34993@intel.com> To: Andrew Morton , David Hildenbrand , Oscar Salvador , Dan Williams , Dave Jiang Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, Huang Ying , Dave Hansen , "Aneesh Kumar K.V" , Jonathan Cameron , Jeff Moyer , Vishal Verma X-Mailer: b4 0.12.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=7769; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=k4XpCfq0ZxU/xUvbPf7nQuvL2vPIJUVSa8ob3/AsbKg=; b=owGbwMvMwCXGf25diOft7jLG02pJDCk77l1RLYhbXWCzitdb+8Lhnk2Tb7DpHwm7w/ZyWs22J ZYZZ1KEO0pZGMS4GGTFFFn+7vnIeExuez5PYIIjzBxWJpAhDFycAjCRdbcY/ueUHputFtleKatx u6V+w0y1WofLhnM4luy4NinkuyBXswXDX9FDsx8wlRm5XmgKW2f8xVBd7s+bqcw/30wwLHTduvi AJBMA X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org The MHP_MEMMAP_ON_MEMORY flag for hotplugged memory is currently restricted to 'memblock_size' chunks of memory being added. Adding a larger span of memory precludes memmap_on_memory semantics. For users of hotplug such as kmem, large amounts of memory might get added from the CXL subsystem. In some cases, this amount may exceed the available 'main memory' to store the memmap for the memory being added. In this case, it is useful to have a way to place the memmap on the memory being added, even if it means splitting the addition into memblock-sized chunks. Change add_memory_resource() to loop over memblock-sized chunks of memory if caller requested memmap_on_memory, and if other conditions for it are met,. Teach try_remove_memory() to also expect that a memory range being removed might have been split up into memblock sized chunks, and to loop through those as needed. Cc: Andrew Morton Cc: David Hildenbrand Cc: Oscar Salvador Cc: Dan Williams Cc: Dave Jiang Cc: Dave Hansen Cc: Huang Ying Suggested-by: David Hildenbrand Signed-off-by: Vishal Verma --- mm/memory_hotplug.c | 154 +++++++++++++++++++++++++++++++--------------------- 1 file changed, 91 insertions(+), 63 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index e9bcacbcbae2..20456f0d28e6 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1286,6 +1286,35 @@ bool mhp_supports_memmap_on_memory(unsigned long size) } EXPORT_SYMBOL_GPL(mhp_supports_memmap_on_memory); +static int add_memory_create_devices(int nid, struct memory_group *group, + u64 start, u64 size, mhp_t mhp_flags) +{ + struct mhp_params params = { .pgprot = pgprot_mhp(PAGE_KERNEL) }; + struct vmem_altmap mhp_altmap = {}; + int ret; + + if ((mhp_flags & MHP_MEMMAP_ON_MEMORY)) { + mhp_altmap.free = PHYS_PFN(size); + mhp_altmap.base_pfn = PHYS_PFN(start); + params.altmap = &mhp_altmap; + } + + /* call arch's memory hotadd */ + ret = arch_add_memory(nid, start, size, ¶ms); + if (ret < 0) + return ret; + + /* create memory block devices after memory was added */ + ret = create_memory_block_devices(start, size, mhp_altmap.alloc, + group); + if (ret) { + arch_remove_memory(start, size, NULL); + return ret; + } + + return 0; +} + /* * NOTE: The caller must call lock_device_hotplug() to serialize hotplug * and online/offline operations (triggered e.g. by sysfs). @@ -1294,11 +1323,10 @@ EXPORT_SYMBOL_GPL(mhp_supports_memmap_on_memory); */ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) { - struct mhp_params params = { .pgprot = pgprot_mhp(PAGE_KERNEL) }; + unsigned long memblock_size = memory_block_size_bytes(); enum memblock_flags memblock_flags = MEMBLOCK_NONE; - struct vmem_altmap mhp_altmap = {}; struct memory_group *group = NULL; - u64 start, size; + u64 start, size, cur_start; bool new_node = false; int ret; @@ -1339,27 +1367,20 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) /* * Self hosted memmap array */ - if (mhp_flags & MHP_MEMMAP_ON_MEMORY) { - if (!mhp_supports_memmap_on_memory(size)) { - ret = -EINVAL; + if ((mhp_flags & MHP_MEMMAP_ON_MEMORY) && + mhp_supports_memmap_on_memory(memblock_size)) { + for (cur_start = start; cur_start < start + size; + cur_start += memblock_size) { + ret = add_memory_create_devices(nid, group, cur_start, + memblock_size, + mhp_flags); + if (ret) + goto error; + } + } else { + ret = add_memory_create_devices(nid, group, start, size, mhp_flags); + if (ret) goto error; - } - mhp_altmap.free = PHYS_PFN(size); - mhp_altmap.base_pfn = PHYS_PFN(start); - params.altmap = &mhp_altmap; - } - - /* call arch's memory hotadd */ - ret = arch_add_memory(nid, start, size, ¶ms); - if (ret < 0) - goto error; - - /* create memory block devices after memory was added */ - ret = create_memory_block_devices(start, size, mhp_altmap.alloc, - group); - if (ret) { - arch_remove_memory(start, size, NULL); - goto error; } if (new_node) { @@ -2035,12 +2056,38 @@ void try_offline_node(int nid) } EXPORT_SYMBOL(try_offline_node); -static int __ref try_remove_memory(u64 start, u64 size) +static void __ref __try_remove_memory(int nid, u64 start, u64 size, + struct vmem_altmap *altmap) { - struct vmem_altmap mhp_altmap = {}; - struct vmem_altmap *altmap = NULL; - unsigned long nr_vmemmap_pages; - int rc = 0, nid = NUMA_NO_NODE; + /* remove memmap entry */ + firmware_map_remove(start, start + size, "System RAM"); + + /* + * Memory block device removal under the device_hotplug_lock is + * a barrier against racing online attempts. + */ + remove_memory_block_devices(start, size); + + mem_hotplug_begin(); + + arch_remove_memory(start, size, altmap); + + if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { + memblock_phys_free(start, size); + memblock_remove(start, size); + } + + release_mem_region_adjustable(start, size); + + if (nid != NUMA_NO_NODE) + try_offline_node(nid); + + mem_hotplug_done(); +} + +static int try_remove_memory(u64 start, u64 size) +{ + int rc, nid = NUMA_NO_NODE; BUG_ON(check_hotplug_memory_range(start, size)); @@ -2058,20 +2105,21 @@ static int __ref try_remove_memory(u64 start, u64 size) return rc; /* - * We only support removing memory added with MHP_MEMMAP_ON_MEMORY in - * the same granularity it was added - a single memory block. + * For memmap_on_memory, the altmaps could have been added on + * a per-memblock basis. Loop through the entire range if so, + * and remove each memblock and its altmap */ if (mhp_memmap_on_memory()) { - nr_vmemmap_pages = walk_memory_blocks(start, size, NULL, - get_nr_vmemmap_pages_cb); - if (nr_vmemmap_pages) { - if (size != memory_block_size_bytes()) { - pr_warn("Refuse to remove %#llx - %#llx," - "wrong granularity\n", - start, start + size); - return -EINVAL; - } + unsigned long memblock_size = memory_block_size_bytes(); + struct vmem_altmap mhp_altmap = {}; + struct vmem_altmap *altmap; + u64 cur_start; + for (cur_start = start; cur_start < start + size; + cur_start += memblock_size) { + unsigned long nr_vmemmap_pages = + walk_memory_blocks(start, memblock_size, NULL, + get_nr_vmemmap_pages_cb); /* * Let remove_pmd_table->free_hugepage_table do the * right thing if we used vmem_altmap when hot-adding @@ -2079,33 +2127,13 @@ static int __ref try_remove_memory(u64 start, u64 size) */ mhp_altmap.alloc = nr_vmemmap_pages; altmap = &mhp_altmap; + __try_remove_memory(nid, cur_start, memblock_size, + altmap); } + } else { + __try_remove_memory(nid, start, size, NULL); } - /* remove memmap entry */ - firmware_map_remove(start, start + size, "System RAM"); - - /* - * Memory block device removal under the device_hotplug_lock is - * a barrier against racing online attempts. - */ - remove_memory_block_devices(start, size); - - mem_hotplug_begin(); - - arch_remove_memory(start, size, altmap); - - if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { - memblock_phys_free(start, size); - memblock_remove(start, size); - } - - release_mem_region_adjustable(start, size); - - if (nid != NUMA_NO_NODE) - try_offline_node(nid); - - mem_hotplug_done(); return 0; } From patchwork Thu Jul 20 07:14:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 13319903 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5DCDBC001DE for ; Thu, 20 Jul 2023 07:14:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230041AbjGTHOf (ORCPT ); Thu, 20 Jul 2023 03:14:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47326 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229476AbjGTHOe (ORCPT ); Thu, 20 Jul 2023 03:14:34 -0400 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 765AA1719; Thu, 20 Jul 2023 00:14:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689837272; x=1721373272; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=t5Tx1xjKMmZzJYwXq10A5dhCDPrE7RYDBM8wVBgMdO0=; b=iWgULLWrgDKbq/NCavQ+zSBgg3DHwarvhAaOTtZYkjXCjUKXF2F/vCrJ FHWDxNseD7x+y/BDxYPPlVvMAfdGUR3/pgKO8i02jogzN1y1Y9gufpcgG CAnp0T5/hqIgY3KWwDVx5pfcaUDyUcp27xLrJBrlF1HteyPdraOjRJAMu OoF3xziU7y+/wW9vsYvV/pwlIOpbBRK4VXsJwI/CIAbqEFsR6+IA9nDgC 5zUacEraA66j08Yq8J2XN64Zk9JDOmprlEIpLIDS/SeS1tlNOJpt82kEp 4vGcjnN/w1PZWG+lWjiAolnO2SMhQcNr/7V8+SYtnRqLSL7niz1FYNPbN A==; X-IronPort-AV: E=McAfee;i="6600,9927,10776"; a="430424022" X-IronPort-AV: E=Sophos;i="6.01,218,1684825200"; d="scan'208";a="430424022" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jul 2023 00:14:31 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10776"; a="794334971" X-IronPort-AV: E=Sophos;i="6.01,218,1684825200"; d="scan'208";a="794334971" Received: from mfgalan-mobl1.amr.corp.intel.com (HELO [192.168.1.200]) ([10.213.172.204]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jul 2023 00:14:30 -0700 From: Vishal Verma Date: Thu, 20 Jul 2023 01:14:24 -0600 Subject: [PATCH v2 3/3] dax/kmem: allow kmem to add memory with memmap_on_memory MIME-Version: 1.0 Message-Id: <20230720-vv-kmem_memmap-v2-3-88bdaab34993@intel.com> References: <20230720-vv-kmem_memmap-v2-0-88bdaab34993@intel.com> In-Reply-To: <20230720-vv-kmem_memmap-v2-0-88bdaab34993@intel.com> To: Andrew Morton , David Hildenbrand , Oscar Salvador , Dan Williams , Dave Jiang Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, Huang Ying , Dave Hansen , "Aneesh Kumar K.V" , Jonathan Cameron , Jeff Moyer , Vishal Verma X-Mailer: b4 0.12.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=4666; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=t5Tx1xjKMmZzJYwXq10A5dhCDPrE7RYDBM8wVBgMdO0=; b=owGbwMvMwCXGf25diOft7jLG02pJDCk77l35ZGnE8/cqw/EfF2OW2vyb9m391imrjrKf35uns 3TSlR0d5zpKWRjEuBhkxRRZ/u75yHhMbns+T2CCI8wcViaQIQxcnAIwkVMJDP/U/uSYVR7RlF/V lsH2ziKjUffFKtY0pZKjzGzthpadntcY/gcnRfPsPtXH5hbMads97c9Ve8UJTBPzXX+mPOJaE5D 5hQEA X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org Large amounts of memory managed by the kmem driver may come in via CXL, and it is often desirable to have the memmap for this memory on the new memory itself. Enroll kmem-managed memory for memmap_on_memory semantics as a default if other requirements for it are met. Add a sysfs override under the dax device to opt out of this behavior. Cc: Andrew Morton Cc: David Hildenbrand Cc: Oscar Salvador Cc: Dan Williams Cc: Dave Jiang Cc: Dave Hansen Cc: Huang Ying Signed-off-by: Vishal Verma --- drivers/dax/dax-private.h | 1 + drivers/dax/bus.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++ drivers/dax/kmem.c | 7 ++++++- 3 files changed, 55 insertions(+), 1 deletion(-) diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h index 27cf2daaaa79..446617b73aea 100644 --- a/drivers/dax/dax-private.h +++ b/drivers/dax/dax-private.h @@ -70,6 +70,7 @@ struct dev_dax { struct ida ida; struct device dev; struct dev_pagemap *pgmap; + bool memmap_on_memory; int nr_range; struct dev_dax_range { unsigned long pgoff; diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 0ee96e6fc426..c8e3ea7c674d 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -1,6 +1,8 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright(c) 2017-2018 Intel Corporation. All rights reserved. */ +#include #include +#include #include #include #include @@ -1269,6 +1271,43 @@ static ssize_t numa_node_show(struct device *dev, } static DEVICE_ATTR_RO(numa_node); +static ssize_t memmap_on_memory_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dev_dax *dev_dax = to_dev_dax(dev); + + return sprintf(buf, "%d\n", dev_dax->memmap_on_memory); +} + +static ssize_t memmap_on_memory_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct dev_dax *dev_dax = to_dev_dax(dev); + struct dax_region *dax_region = dev_dax->region; + ssize_t rc; + bool val; + + rc = kstrtobool(buf, &val); + if (rc) + return rc; + + device_lock(dax_region->dev); + if (!dax_region->dev->driver) { + device_unlock(dax_region->dev); + return -ENXIO; + } + + if (mhp_supports_memmap_on_memory(memory_block_size_bytes())) + dev_dax->memmap_on_memory = val; + else + rc = -ENXIO; + + device_unlock(dax_region->dev); + return rc == 0 ? len : rc; +} +static DEVICE_ATTR_RW(memmap_on_memory); + static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n) { struct device *dev = container_of(kobj, struct device, kobj); @@ -1295,6 +1334,7 @@ static struct attribute *dev_dax_attributes[] = { &dev_attr_align.attr, &dev_attr_resource.attr, &dev_attr_numa_node.attr, + &dev_attr_memmap_on_memory.attr, NULL, }; @@ -1400,6 +1440,14 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data) dev_dax->align = dax_region->align; ida_init(&dev_dax->ida); + /* + * If supported by memory_hotplug, allow memmap_on_memory behavior by + * default. This can be overridden via sysfs before handing the memory + * over to kmem if desired. + */ + if (mhp_supports_memmap_on_memory(memory_block_size_bytes())) + dev_dax->memmap_on_memory = true; + inode = dax_inode(dax_dev); dev->devt = inode->i_rdev; dev->bus = &dax_bus_type; diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index 898ca9505754..e6976a79093d 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -56,6 +56,7 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) unsigned long total_len = 0; struct dax_kmem_data *data; int i, rc, mapped = 0; + mhp_t mhp_flags; int numa_node; /* @@ -136,12 +137,16 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) */ res->flags = IORESOURCE_SYSTEM_RAM; + mhp_flags = MHP_NID_IS_MGID; + if (dev_dax->memmap_on_memory) + mhp_flags |= MHP_MEMMAP_ON_MEMORY; + /* * Ensure that future kexec'd kernels will not treat * this as RAM automatically. */ rc = add_memory_driver_managed(data->mgid, range.start, - range_len(&range), kmem_name, MHP_NID_IS_MGID); + range_len(&range), kmem_name, mhp_flags); if (rc) { dev_warn(dev, "mapping%d: %#llx-%#llx memory add failed\n",