From patchwork Wed Aug 2 05:55:38 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: 13337666 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 82F7EC001DE for ; Wed, 2 Aug 2023 05:56:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232078AbjHBF4D (ORCPT ); Wed, 2 Aug 2023 01:56:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232051AbjHBF4D (ORCPT ); Wed, 2 Aug 2023 01:56:03 -0400 Received: from mgamail.intel.com (unknown [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B0150212B; Tue, 1 Aug 2023 22:56:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1690955762; x=1722491762; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=PQ203zHCVt3CEYS9d0oE1EzhXByb08+AR/dYJJo5JtE=; b=e+bQgLyLMnmUwOElLCGOWE496Jz5wtz/6sw4wxwXKBbSjSESJGMSS9c3 SJGftQke+IM45bImo7EWtYJEd6wEDC7l5xd6ogWudtmeO6FSh1ENz0JaN x2MSyTOmwaslnCI2FxARM93q8IjgkewbtOrNeOCpcUzhc7B/K/tvE6TZC pevbG4Ct5HUlE4YNgnHlX0SkoDZ7eVtlaRXiAzBjMhvngJ6+qHlMneZaE aZ2hY+zPskOTISjb8gPdKYy0cry00vPo/JaegtnpPdNFQEVAPo2TwCq8j /z05YWYFXDmE4dxinQjcjYqJ2+UP/AaDkEGlmquSstdmhp2FkfAn2Rb6a A==; X-IronPort-AV: E=McAfee;i="6600,9927,10789"; a="455857453" X-IronPort-AV: E=Sophos;i="6.01,248,1684825200"; d="scan'208";a="455857453" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Aug 2023 22:55:47 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10789"; a="852746663" X-IronPort-AV: E=Sophos;i="6.01,248,1684825200"; d="scan'208";a="852746663" Received: from hongrudi-mobl.amr.corp.intel.com (HELO [192.168.1.200]) ([10.209.173.200]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Aug 2023 22:55:46 -0700 From: Vishal Verma Date: Tue, 01 Aug 2023 23:55:38 -0600 Subject: [PATCH v3 2/2] dax/kmem: allow kmem to add memory with memmap_on_memory MIME-Version: 1.0 Message-Id: <20230801-vv-kmem_memmap-v3-2-406e9aaf5689@intel.com> References: <20230801-vv-kmem_memmap-v3-0-406e9aaf5689@intel.com> In-Reply-To: <20230801-vv-kmem_memmap-v3-0-406e9aaf5689@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 0.12.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=4390; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=PQ203zHCVt3CEYS9d0oE1EzhXByb08+AR/dYJJo5JtE=; b=owGbwMvMwCXGf25diOft7jLG02pJDCkn3z+4nj37ncR5uxXal6v0S2/oPH2YPFe2vKpGoFDzX nY91wzljlIWBjEuBlkxRZa/ez4yHpPbns8TmOAIM4eVCWQIAxenAEwkrJDhr4BpPvuEZLYzx69G be1YVSb5Z1rUqS0V8/NTFq+VXfGvM4qRYalrzD/JfS4qmekPJf5JbDEWn1yyqlNnTsAsTkvXh9k LeQA= 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. Add a sysfs override under the dax device to opt out of this behavior. Cc: Andrew Morton Cc: David Hildenbrand Cc: Michal Hocko 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 | 42 ++++++++++++++++++++++++++++++++++++++++++ drivers/dax/kmem.c | 8 +++++++- 3 files changed, 50 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..e9c0349b6244 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -1269,6 +1269,40 @@ 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; + } + + dev_dax->memmap_on_memory = val; + + 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 +1329,7 @@ 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 +1435,13 @@ 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. + */ + 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 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",