From patchwork Wed Oct 25 22:44:33 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: 13436909 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 80C5A28693 for ; Wed, 25 Oct 2023 22:44:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="SxEtYgMs" Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5E3BF115; Wed, 25 Oct 2023 15:44:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1698273897; x=1729809897; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=hEIpF+H2iWRMoZGPvwzbL8B1g/l212Q9ts7SomwLAKg=; b=SxEtYgMsD9KTbdF5ikCENwakHS6oyr3QVhxOXjbzzn+Urg9gOBmXZubo cT+kaozpvkUaTghq3aE8iCRLHkoOfN5UJn60R+VoJEDS25WJa5cWwQ9l/ z68Ty3tlmdFfwlqP5lPJiJGDtvKnucOIrjF61eQelu8U84EQouh9qayvX pl6pnTJ96fK+eHY4eLAl1MKQd7l/4NDUT+xmDOftpsq5JrjwQ7RbB0zjv 5Wl3uPe8W8MFwH0XQ4HCTD0sArm+JJq3h0UvucNaEdfkp8iYZApwQcfCV 1GXpqU83fQTjGuqalljk5v9vurkaiXu1CwjMCfkWk3UIUzipg1hzmLHNG A==; X-IronPort-AV: E=McAfee;i="6600,9927,10874"; a="473650442" X-IronPort-AV: E=Sophos;i="6.03,252,1694761200"; d="scan'208";a="473650442" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Oct 2023 15:44:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10874"; a="708846721" X-IronPort-AV: E=Sophos;i="6.03,252,1694761200"; d="scan'208";a="708846721" Received: from nmckubrx-mobl.amr.corp.intel.com (HELO [192.168.1.200]) ([10.212.68.190]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Oct 2023 15:44:50 -0700 From: Vishal Verma Date: Wed, 25 Oct 2023 16:44:33 -0600 Subject: [PATCH v7 1/3] mm/memory_hotplug: replace an open-coded kmemdup() in add_memory_resource() Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231025-vv-kmem_memmap-v7-1-4a76d7652df5@intel.com> References: <20231025-vv-kmem_memmap-v7-0-4a76d7652df5@intel.com> In-Reply-To: <20231025-vv-kmem_memmap-v7-0-4a76d7652df5@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" , Michal Hocko , Jonathan Cameron , Jeff Moyer , Vishal Verma X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=openpgp-sha256; l=1362; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=hEIpF+H2iWRMoZGPvwzbL8B1g/l212Q9ts7SomwLAKg=; b=owGbwMvMwCXGf25diOft7jLG02pJDKmWsxJWmYp2Tak1DxJWVlQW1jWL/jDzy6c113tEP+XOW HL4TWZMRykLgxgXg6yYIsvfPR8Zj8ltz+cJTHCEmcPKBDKEgYtTACZy/Scjwx6zeNcOMf0D/k92 FS0SOXguPq7sz44vulelEq7dPf/3RxIjw4ZdJntVZnX5FnH6XT+YkMdUWZv4zkbC44169ozqlvo cbgA= X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF A review of the memmap_on_memory modifications to add_memory_resource() revealed an instance of an open-coded kmemdup(). Replace it with kmemdup(). Cc: Andrew Morton Cc: David Hildenbrand Cc: Michal Hocko Cc: Oscar Salvador Cc: Dan Williams Reported-by: Dan Williams Reviewed-by: David Hildenbrand Signed-off-by: Vishal Verma --- mm/memory_hotplug.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index f8d3e7427e32..6be7de9efa55 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1439,11 +1439,11 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) if (mhp_flags & MHP_MEMMAP_ON_MEMORY) { if (mhp_supports_memmap_on_memory(size)) { mhp_altmap.free = memory_block_memmap_on_memory_pages(); - params.altmap = kmalloc(sizeof(struct vmem_altmap), GFP_KERNEL); + params.altmap = kmemdup(&mhp_altmap, + sizeof(struct vmem_altmap), + GFP_KERNEL); if (!params.altmap) goto error; - - memcpy(params.altmap, &mhp_altmap, sizeof(mhp_altmap)); } /* fallback to not using altmap */ } From patchwork Wed Oct 25 22:44:34 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: 13436911 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 80C6331A75 for ; Wed, 25 Oct 2023 22:45:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="b56TyI49" Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 049C6DC; Wed, 25 Oct 2023 15:44:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1698273899; x=1729809899; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=ndMaEWGdwlBZiUCGL9AFKr6E35jyc9m/F17PjjwLe7E=; b=b56TyI49JIbulkQy/9/+llClWo5TkcUvnAfPfA5PEH3sLVlxdfPcpkRH YxdKZ5BaoUKH6a4WqgFOpDRLzQkKfAP7R6fxq/T0Z8+nvBQHmZmCmtxhh +IvmrJWWQJysIpXkHRYkwtKE2Vq8fozhK9kYdtcxJdi0VlVyMpAa8+r5f DqKwkuY64D5UPz4Hws2U+GQ1IGPxvs+NiR9Th+MFthsVak1c9Wlao7wYZ Kwc3LvJZUdQYjqN/o58p2mgBFG0WWcw3+SX/LaQv8VzKUjeB+6mckR91Q kPKsJe4/+jRm5YGLWsEW5oy+cBYPTwUSn7sbgWVPSD0zhILvLjd94fuPc Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10874"; a="473650457" X-IronPort-AV: E=Sophos;i="6.03,252,1694761200"; d="scan'208";a="473650457" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Oct 2023 15:44:52 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10874"; a="708846731" X-IronPort-AV: E=Sophos;i="6.03,252,1694761200"; d="scan'208";a="708846731" Received: from nmckubrx-mobl.amr.corp.intel.com (HELO [192.168.1.200]) ([10.212.68.190]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Oct 2023 15:44:51 -0700 From: Vishal Verma Date: Wed, 25 Oct 2023 16:44:34 -0600 Subject: [PATCH v7 2/3] mm/memory_hotplug: split memmap_on_memory requests across memblocks Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231025-vv-kmem_memmap-v7-2-4a76d7652df5@intel.com> References: <20231025-vv-kmem_memmap-v7-0-4a76d7652df5@intel.com> In-Reply-To: <20231025-vv-kmem_memmap-v7-0-4a76d7652df5@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" , Michal Hocko , Jonathan Cameron , Jeff Moyer , Vishal Verma X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=openpgp-sha256; l=9833; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=ndMaEWGdwlBZiUCGL9AFKr6E35jyc9m/F17PjjwLe7E=; b=owGbwMvMwCXGf25diOft7jLG02pJDKmWsxLWHPj5TybkrKyIeqN7o9Hrz15xByfurLrud3X9E /0Lx9Pmd5SyMIhxMciKKbL83fOR8Zjc9nyewARHmDmsTCBDGLg4BWAiXxsZGe7Ef6hS3VIin7Gu +v/N/Y9sWHbZzC55tXGf+OP5niaPZEoZGXbed9175P/nkz4vFk59HatW5WHsEXqCpWVya59FX8V MHR4A X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF The MHP_MEMMAP_ON_MEMORY flag for hotplugged memory is 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. This does preclude being able to use PUD mappings in the direct map; a proposal to how this could be optimized in the future is laid out here[1]. [1]: https://lore.kernel.org/linux-mm/b6753402-2de9-25b2-36e9-eacd49752b19@redhat.com/ Cc: Andrew Morton Cc: David Hildenbrand Cc: Michal Hocko Cc: Oscar Salvador Cc: Dan Williams Cc: Dave Jiang Cc: Dave Hansen Cc: Huang Ying Suggested-by: David Hildenbrand Reviewed-by: Dan Williams Signed-off-by: Vishal Verma --- mm/memory_hotplug.c | 209 ++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 144 insertions(+), 65 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 6be7de9efa55..b97035193090 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1380,6 +1380,48 @@ static bool mhp_supports_memmap_on_memory(unsigned long size) return arch_supports_memmap_on_memory(vmemmap_size); } +static int create_altmaps_and_memory_blocks(int nid, struct memory_group *group, + u64 start, u64 size) +{ + unsigned long memblock_size = memory_block_size_bytes(); + u64 cur_start; + int ret; + + for (cur_start = start; cur_start < start + size; + cur_start += memblock_size) { + struct mhp_params params = { .pgprot = + pgprot_mhp(PAGE_KERNEL) }; + struct vmem_altmap mhp_altmap = { + .base_pfn = PHYS_PFN(cur_start), + .end_pfn = PHYS_PFN(cur_start + memblock_size - 1), + }; + + mhp_altmap.free = memory_block_memmap_on_memory_pages(); + params.altmap = kmemdup(&mhp_altmap, sizeof(struct vmem_altmap), + GFP_KERNEL); + if (!params.altmap) + return -ENOMEM; + + /* call arch's memory hotadd */ + ret = arch_add_memory(nid, cur_start, memblock_size, ¶ms); + if (ret < 0) { + kfree(params.altmap); + return ret; + } + + /* create memory block devices after memory was added */ + ret = create_memory_block_devices(cur_start, memblock_size, + params.altmap, group); + if (ret) { + arch_remove_memory(cur_start, memblock_size, NULL); + kfree(params.altmap); + return ret; + } + } + + return 0; +} + /* * NOTE: The caller must call lock_device_hotplug() to serialize hotplug * and online/offline operations (triggered e.g. by sysfs). @@ -1390,10 +1432,6 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) { struct mhp_params params = { .pgprot = pgprot_mhp(PAGE_KERNEL) }; enum memblock_flags memblock_flags = MEMBLOCK_NONE; - struct vmem_altmap mhp_altmap = { - .base_pfn = PHYS_PFN(res->start), - .end_pfn = PHYS_PFN(res->end), - }; struct memory_group *group = NULL; u64 start, size; bool new_node = false; @@ -1436,28 +1474,22 @@ 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)) { - mhp_altmap.free = memory_block_memmap_on_memory_pages(); - params.altmap = kmemdup(&mhp_altmap, - sizeof(struct vmem_altmap), - GFP_KERNEL); - if (!params.altmap) - goto error; + if ((mhp_flags & MHP_MEMMAP_ON_MEMORY) && + mhp_supports_memmap_on_memory(memory_block_size_bytes())) { + ret = create_altmaps_and_memory_blocks(nid, group, start, size); + if (ret) + goto error; + } else { + 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, NULL, group); + if (ret) { + arch_remove_memory(start, size, NULL); + goto error; } - /* fallback to not using altmap */ - } - - /* call arch's memory hotadd */ - ret = arch_add_memory(nid, start, size, ¶ms); - if (ret < 0) - goto error_free; - - /* create memory block devices after memory was added */ - ret = create_memory_block_devices(start, size, params.altmap, group); - if (ret) { - arch_remove_memory(start, size, NULL); - goto error_free; } if (new_node) { @@ -1494,8 +1526,6 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) walk_memory_blocks(start, size, NULL, online_memory_block); return ret; -error_free: - kfree(params.altmap); error: if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) memblock_remove(start, size); @@ -2076,6 +2106,16 @@ static int test_has_altmap_cb(struct memory_block *mem, void *arg) return 0; } +static int count_memory_range_altmaps_cb(struct memory_block *mem, void *arg) +{ + u64 *num_altmaps = (u64 *)arg; + + if (mem->altmap) + *num_altmaps += 1; + + return 0; +} + static int check_cpu_on_node(int nid) { int cpu; @@ -2146,11 +2186,69 @@ void try_offline_node(int nid) } EXPORT_SYMBOL(try_offline_node); -static int __ref try_remove_memory(u64 start, u64 size) +static void __ref remove_memory_blocks_and_altmaps(u64 start, u64 size) { - struct memory_block *mem; - int rc = 0, nid = NUMA_NO_NODE; + unsigned long memblock_size = memory_block_size_bytes(); struct vmem_altmap *altmap = NULL; + struct memory_block *mem; + u64 cur_start; + int rc; + + /* + * 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. + */ + for (cur_start = start; cur_start < start + size; + cur_start += memblock_size) { + rc = walk_memory_blocks(cur_start, memblock_size, &mem, + test_has_altmap_cb); + if (rc) { + altmap = mem->altmap; + /* + * Mark altmap NULL so that we can add a debug + * check on memblock free. + */ + mem->altmap = NULL; + } + + remove_memory_block_devices(cur_start, memblock_size); + + arch_remove_memory(cur_start, memblock_size, altmap); + + /* Verify that all vmemmap pages have actually been freed. */ + if (altmap) { + WARN(altmap->alloc, "Altmap not fully unmapped"); + kfree(altmap); + } + } +} + +static int memory_blocks_have_altmaps(u64 start, u64 size) +{ + u64 num_memblocks = size / memory_block_size_bytes(); + u64 num_altmaps = 0; + + if (!mhp_memmap_on_memory()) + return 0; + + walk_memory_blocks(start, size, &num_altmaps, + count_memory_range_altmaps_cb); + + if (num_altmaps == 0) + return 0; + + if (num_memblocks != num_altmaps) { + WARN_ONCE(1, "Not all memblocks in range have altmaps"); + return -EINVAL; + } + + return 1; +} + +static int __ref try_remove_memory(u64 start, u64 size) +{ + int rc, nid = NUMA_NO_NODE; BUG_ON(check_hotplug_memory_range(start, size)); @@ -2167,45 +2265,25 @@ static int __ref try_remove_memory(u64 start, u64 size) if (rc) return rc; - /* - * We only support removing memory added with MHP_MEMMAP_ON_MEMORY in - * the same granularity it was added - a single memory block. - */ - if (mhp_memmap_on_memory()) { - rc = walk_memory_blocks(start, size, &mem, test_has_altmap_cb); - if (rc) { - if (size != memory_block_size_bytes()) { - pr_warn("Refuse to remove %#llx - %#llx," - "wrong granularity\n", - start, start + size); - return -EINVAL; - } - altmap = mem->altmap; - /* - * Mark altmap NULL so that we can add a debug - * check on memblock free. - */ - mem->altmap = 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); - - /* Verify that all vmemmap pages have actually been freed. */ - if (altmap) { - WARN(altmap->alloc, "Altmap not fully unmapped"); - kfree(altmap); + rc = memory_blocks_have_altmaps(start, size); + if (rc < 0) { + goto err; + } else if (rc == 0) { + /* + * Memory block device removal under the device_hotplug_lock is + * a barrier against racing online attempts. + * No altmaps present, do the removal directly + */ + remove_memory_block_devices(start, size); + arch_remove_memory(start, size, NULL); + } else { + /* all memblocks in the range have altmaps */ + remove_memory_blocks_and_altmaps(start, size); } if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { @@ -2218,8 +2296,9 @@ static int __ref try_remove_memory(u64 start, u64 size) if (nid != NUMA_NO_NODE) try_offline_node(nid); +err: mem_hotplug_done(); - return 0; + return (rc < 0 ? rc : 0); } /** From patchwork Wed Oct 25 22:44:35 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: 13436910 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5DA6B2E63B for ; Wed, 25 Oct 2023 22:44:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="PD3wnLkz" Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 26D9E116; Wed, 25 Oct 2023 15:44:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1698273898; x=1729809898; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=mEPqGi0w6uK1G2oMRp9GXgOlOlinp7OhMTBnsnQmtwo=; b=PD3wnLkz2tygg+9IWqBEPMXIbFrKkNJmk/HKwctX562zQw+Tvv3KFjm1 aLjihFJy2lUm16GSnPTCaxkV6r6EIxlIL98SiwiCFuofIxBhY/UlmTT7/ x3Fok0Nb0K78mwOL3DahoR2vVTlv92Qk7Zf8zFcSDp2P0BDx8fRutjVoN J/ohWoEBGg9XPU+h26Bf3NMpDpU81YEIfpxC64jSbQFMJSrUicgPr8491 HPMceEgn//uFRlaSjVXVTtmnCkApT3HiXctEBSh9KS1AdwXXqncwwhj7Q zIOqF6kjzgX+jU3GNtVEEHK/WRYjBSsVX+JPKibpFAbtW5QI5BBmvPGUR A==; X-IronPort-AV: E=McAfee;i="6600,9927,10874"; a="473650467" X-IronPort-AV: E=Sophos;i="6.03,252,1694761200"; d="scan'208";a="473650467" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Oct 2023 15:44:53 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10874"; a="708846737" X-IronPort-AV: E=Sophos;i="6.03,252,1694761200"; d="scan'208";a="708846737" Received: from nmckubrx-mobl.amr.corp.intel.com (HELO [192.168.1.200]) ([10.212.68.190]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Oct 2023 15:44:52 -0700 From: Vishal Verma Date: Wed, 25 Oct 2023 16:44:35 -0600 Subject: [PATCH v7 3/3] dax/kmem: allow kmem to add memory with memmap_on_memory Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231025-vv-kmem_memmap-v7-3-4a76d7652df5@intel.com> References: <20231025-vv-kmem_memmap-v7-0-4a76d7652df5@intel.com> In-Reply-To: <20231025-vv-kmem_memmap-v7-0-4a76d7652df5@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" , Michal Hocko , Jonathan Cameron , Jeff Moyer , Vishal Verma , Jonathan Cameron X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=openpgp-sha256; l=4972; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=mEPqGi0w6uK1G2oMRp9GXgOlOlinp7OhMTBnsnQmtwo=; b=owGbwMvMwCXGf25diOft7jLG02pJDKmWsxIm2j5sMK2Rlc/4flfo6tdP+y3Fvfnip/y6583My PQqmLm0o5SFQYyLQVZMkeXvno+Mx+S25/MEJjjCzGFlAhnCwMUpABN538jIcNtXk1Ei4sPciT8Y LYvUskIPurWm5kSdye9leXj+wCOBOYwM/w6Hvpz8dcnkvCrVy6s4L4swFRSxfiq3f7N6Z9PPzOQ 4BgA= X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF 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 if the dax region originates via CXL. For non-CXL dax regions, retain the existing default behavior of hot adding without memmap_on_memory semantics. Cc: Andrew Morton Cc: David Hildenbrand Cc: Michal Hocko Cc: Oscar Salvador Cc: Dan Williams Cc: Dave Jiang Cc: Dave Hansen Cc: Huang Ying Reviewed-by: Jonathan Cameron Reviewed-by: David Hildenbrand Signed-off-by: Vishal Verma Reviewed-by: "Huang, Ying" --- drivers/dax/bus.h | 1 + drivers/dax/dax-private.h | 1 + drivers/dax/bus.c | 3 +++ drivers/dax/cxl.c | 1 + drivers/dax/hmem/hmem.c | 1 + drivers/dax/kmem.c | 8 +++++++- drivers/dax/pmem.c | 1 + 7 files changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h index 1ccd23360124..cbbf64443098 100644 --- a/drivers/dax/bus.h +++ b/drivers/dax/bus.h @@ -23,6 +23,7 @@ struct dev_dax_data { struct dev_pagemap *pgmap; resource_size_t size; int id; + bool memmap_on_memory; }; struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data); 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..ad9f821b8c78 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -367,6 +367,7 @@ static ssize_t create_store(struct device *dev, struct device_attribute *attr, .dax_region = dax_region, .size = 0, .id = -1, + .memmap_on_memory = false, }; struct dev_dax *dev_dax = devm_create_dev_dax(&data); @@ -1400,6 +1401,8 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data) dev_dax->align = dax_region->align; ida_init(&dev_dax->ida); + dev_dax->memmap_on_memory = data->memmap_on_memory; + inode = dax_inode(dax_dev); dev->devt = inode->i_rdev; dev->bus = &dax_bus_type; diff --git a/drivers/dax/cxl.c b/drivers/dax/cxl.c index 8bc9d04034d6..c696837ab23c 100644 --- a/drivers/dax/cxl.c +++ b/drivers/dax/cxl.c @@ -26,6 +26,7 @@ static int cxl_dax_region_probe(struct device *dev) .dax_region = dax_region, .id = -1, .size = range_len(&cxlr_dax->hpa_range), + .memmap_on_memory = true, }; return PTR_ERR_OR_ZERO(devm_create_dev_dax(&data)); diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c index 5d2ddef0f8f5..b9da69f92697 100644 --- a/drivers/dax/hmem/hmem.c +++ b/drivers/dax/hmem/hmem.c @@ -36,6 +36,7 @@ static int dax_hmem_probe(struct platform_device *pdev) .dax_region = dax_region, .id = -1, .size = region_idle ? 0 : range_len(&mri->range), + .memmap_on_memory = false, }; return PTR_ERR_OR_ZERO(devm_create_dev_dax(&data)); diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index c57acb73e3db..0aa6c45a4e5a 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -12,6 +12,7 @@ #include #include #include +#include #include "dax-private.h" #include "bus.h" @@ -56,6 +57,7 @@ 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 +138,16 @@ 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", diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c index ae0cb113a5d3..f3c6c67b8412 100644 --- a/drivers/dax/pmem.c +++ b/drivers/dax/pmem.c @@ -63,6 +63,7 @@ static struct dev_dax *__dax_pmem_probe(struct device *dev) .id = id, .pgmap = &pgmap, .size = range_len(&range), + .memmap_on_memory = false, }; return devm_create_dev_dax(&data);