From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Hansen Subject: Re: [PATCH 4/7] node: Add memory caching attributes Date: Wed, 14 Nov 2018 16:40:51 -0800 Message-ID: References: <20181114224921.12123-2-keith.busch@intel.com> <20181114224921.12123-5-keith.busch@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20181114224921.12123-5-keith.busch@intel.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Keith Busch , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-mm@kvack.org Cc: Greg Kroah-Hartman , Rafael Wysocki , Dan Williams List-Id: linux-acpi@vger.kernel.org On 11/14/18 2:49 PM, Keith Busch wrote: > System memory may have side caches to help improve access speed. While > the system provided cache is transparent to the software accessing > these memory ranges, applications can optimize their own access based > on cache attributes. > > In preparation for such systems, provide a new API for the kernel to > register these memory side caches under the memory node that provides it. > > The kernel's sysfs representation is modeled from the cpu cacheinfo > attributes, as seen from /sys/devices/system/cpu/cpuX/cache/. Unlike CPU > cacheinfo, though, a higher node's memory cache level is nearer to the > CPU, while lower levels are closer to the backing memory. Also unlike > CPU cache, the system handles flushing any dirty cached memory to the > last level the memory on a power failure if the range is persistent. > > The exported attributes are the cache size, the line size, associativity, > and write back policy. Could you also include an example of the layout?