From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 301D04685 for ; Thu, 22 Feb 2024 00:01:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708560103; cv=none; b=Sh+ap6wUl5ZoQOF85kXIiH7HsyYohe/+xjdrff37zVO/spS7XtlfacG8VYIqeci9CiZQKXUsMLwyVEiigIs8qW0OFC5OC7EhYLBY50LiL7HHHEW12ibnfj6PI4aeWDWVMCxU+634zdKVViznFpcxwec0QJou/W6S0OX551ehvO8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708560103; c=relaxed/simple; bh=EWzP6tqqaYXBqtJVm+0j5D6u8Tg8XKUghCfNNHcGF58=; h=Date:To:From:Subject:Message-Id; b=lQtPUy1YeNNalc2EufvdsnfokZJQYwfhGPTvgfJFIP58MgRmxEYdeUMTQO/ucgD6PREVVyMUblwSdDHcoeb/63kcovj/FWa3DGhBDLiUjOJSqWWPetQwVOPKQDDyaaYmny9Mv9ROw2M6l98c11xWRbDornuv5pI1ZrpP4DOMkuc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=qRHFwiTv; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="qRHFwiTv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06849C43390; Thu, 22 Feb 2024 00:01:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1708560103; bh=EWzP6tqqaYXBqtJVm+0j5D6u8Tg8XKUghCfNNHcGF58=; h=Date:To:From:Subject:From; b=qRHFwiTvCd3xAhKPabXpLjPriRiutmWzCcEpkbqRfACjkOtx0qSekg9P2dLFaQfud 9MZ7vUoLO0iP2ZEm/AqYbxThxGMC8sHX7qFqCbUd3kxNvWOmuxt1lg4/4qFkYoGI6w 40GnzHkPs2M8++noCLnmN4YIxOH2PfmvBfbMzQKE= Date: Wed, 21 Feb 2024 16:01:42 -0800 To: mm-commits@vger.kernel.org,ying.huang@intel.com,willy@infradead.org,osalvador@suse.de,mhocko@suse.com,lizhijian@fujitsu.com,Jonathan.Cameron@huawei.com,gregkh@linuxfoundation.org,david@redhat.com,dave.jiang@intel.com,dave.hansen@linux.intel.com,dan.j.williams@intel.com,alison.schofield@intel.com,vishal.l.verma@intel.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] dax-add-a-sysfs-knob-to-control-memmap_on_memory-behavior.patch removed from -mm tree Message-Id: <20240222000143.06849C43390@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: dax: add a sysfs knob to control memmap_on_memory behavior has been removed from the -mm tree. Its filename was dax-add-a-sysfs-knob-to-control-memmap_on_memory-behavior.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Vishal Verma Subject: dax: add a sysfs knob to control memmap_on_memory behavior Date: Wed, 24 Jan 2024 12:03:50 -0800 Add a sysfs knob for dax devices to control the memmap_on_memory setting if the dax device were to be hotplugged as system memory. The default memmap_on_memory setting for dax devices originating via pmem or hmem is set to 'false' - i.e. no memmap_on_memory semantics, to preserve legacy behavior. For dax devices via CXL, the default is on. The sysfs control allows the administrator to override the above defaults if needed. Link: https://lkml.kernel.org/r/20240124-vv-dax_abi-v7-5-20d16cb8d23d@intel.com Signed-off-by: Vishal Verma Tested-by: Li Zhijian Reviewed-by: Jonathan Cameron Reviewed-by: David Hildenbrand Reviewed-by: Huang, Ying Reviewed-by: Alison Schofield Cc: Dan Williams Cc: Dave Jiang Cc: Dave Hansen Cc: Greg Kroah-Hartman Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Oscar Salvador Signed-off-by: Andrew Morton --- Documentation/ABI/testing/sysfs-bus-dax | 17 ++++++++ drivers/dax/bus.c | 43 ++++++++++++++++++++++ 2 files changed, 60 insertions(+) --- a/Documentation/ABI/testing/sysfs-bus-dax~dax-add-a-sysfs-knob-to-control-memmap_on_memory-behavior +++ a/Documentation/ABI/testing/sysfs-bus-dax @@ -134,3 +134,20 @@ KernelVersion: v5.1 Contact: nvdimm@lists.linux.dev Description: (RO) The id attribute indicates the region id of a dax region. + +What: /sys/bus/dax/devices/daxX.Y/memmap_on_memory +Date: January, 2024 +KernelVersion: v6.8 +Contact: nvdimm@lists.linux.dev +Description: + (RW) Control the memmap_on_memory setting if the dax device + were to be hotplugged as system memory. This determines whether + the 'altmap' for the hotplugged memory will be placed on the + device being hotplugged (memmap_on_memory=1) or if it will be + placed on regular memory (memmap_on_memory=0). This attribute + must be set before the device is handed over to the 'kmem' + driver (i.e. hotplugged into system-ram). Additionally, this + depends on CONFIG_MHP_MEMMAP_ON_MEMORY, and a globally enabled + memmap_on_memory parameter for memory_hotplug. This is + typically set on the kernel command line - + memory_hotplug.memmap_on_memory set to 'true' or 'force'." --- a/drivers/dax/bus.c~dax-add-a-sysfs-knob-to-control-memmap_on_memory-behavior +++ a/drivers/dax/bus.c @@ -1349,6 +1349,48 @@ static ssize_t numa_node_show(struct 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 sysfs_emit(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); + bool val; + int rc; + + rc = kstrtobool(buf, &val); + if (rc) + return rc; + + if (val == true && !mhp_supports_memmap_on_memory()) { + dev_dbg(dev, "memmap_on_memory is not available\n"); + return -EOPNOTSUPP; + } + + rc = down_write_killable(&dax_dev_rwsem); + if (rc) + return rc; + + if (dev_dax->memmap_on_memory != val && dev->driver && + to_dax_drv(dev->driver)->type == DAXDRV_KMEM_TYPE) { + up_write(&dax_dev_rwsem); + return -EBUSY; + } + + dev_dax->memmap_on_memory = val; + up_write(&dax_dev_rwsem); + + return len; +} +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); @@ -1375,6 +1417,7 @@ static struct attribute *dev_dax_attribu &dev_attr_align.attr, &dev_attr_resource.attr, &dev_attr_numa_node.attr, + &dev_attr_memmap_on_memory.attr, NULL, }; _ Patches currently in -mm which might be from vishal.l.verma@intel.com are