From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752164AbbCZRbK (ORCPT ); Thu, 26 Mar 2015 13:31:10 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:35864 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751455AbbCZRbH (ORCPT ); Thu, 26 Mar 2015 13:31:07 -0400 Message-ID: <55144257.8050004@plexistor.com> Date: Thu, 26 Mar 2015 19:31:03 +0200 From: Boaz Harrosh User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Christoph Hellwig CC: linux-nvdimm@ml01.01.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, ross.zwisler@linux.intel.com, axboe@kernel.dk Subject: Re: another pmem variant V2 References: <1427358764-6126-1-git-send-email-hch@lst.de> <55143A8B.2060304@plexistor.com> <20150326171858.GA25575@lst.de> In-Reply-To: <20150326171858.GA25575@lst.de> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/26/2015 07:18 PM, Christoph Hellwig wrote: > On Thu, Mar 26, 2015 at 06:57:47PM +0200, Boaz Harrosh wrote: >> For one this auto discovery of yours is very (very) nice but is a bit >> inconvenience. Before I would reserve a big chuck on each NUMA range >> on Kernel's memmap= And then at pmem map= would slice and dice it >> as I want hot style on modprobe with no need for reboot. Now I need >> to do it on reboot theoretically. (You know xfstest needs lots of devices >> some big some small ;-)) > > Slicing up a block device based on kernel options is not exactly a smart > idea. We have partitions that are perfectly fine for that. If you > really don't are about persistance of your partitioning you can just > set up a device mapper table. No need to reinvent the wheel. > I know! fdisk is my friend, I know. But I hope you are not ignoring my real problem. any two memmap= ranges will halt the boot. Specially if they are dis-contiguous. Also I need the contiguous variant split into two devices because they might belong to two NUMA nodes. It is very hard to manage if a NUMA crossing is in a middle of a single pmemX device The way we like to configure it is that each /dev/pmem belongs to a single NUMA node. And in a multy device setup each CPU node allocates from "his" pmem device If there is space. (And it lets me set application affinity if need to) BTW: Will device mapper let me call ->direct_access() Thanks Boaz