From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C918ECE566 for ; Fri, 21 Sep 2018 00:16:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5A0E921536 for ; Fri, 21 Sep 2018 00:16:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5A0E921536 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388820AbeIUGC3 (ORCPT ); Fri, 21 Sep 2018 02:02:29 -0400 Received: from mga06.intel.com ([134.134.136.31]:53055 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727247AbeIUGC3 (ORCPT ); Fri, 21 Sep 2018 02:02:29 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Sep 2018 17:16:22 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,282,1534834800"; d="scan'208";a="74733750" Received: from ahduyck-mobl.amr.corp.intel.com (HELO [10.7.198.152]) ([10.7.198.152]) by orsmga007.jf.intel.com with ESMTP; 20 Sep 2018 17:16:22 -0700 Subject: Re: [PATCH v4 5/5] nvdimm: Schedule device registration on node local to the device To: Dan Williams Cc: Linux MM , Linux Kernel Mailing List , linux-nvdimm , Pasha Tatashin , Michal Hocko , Dave Jiang , Ingo Molnar , Dave Hansen , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Andrew Morton , Logan Gunthorpe , "Kirill A. Shutemov" References: <20180920215824.19464.8884.stgit@localhost.localdomain> <20180920222951.19464.39241.stgit@localhost.localdomain> From: Alexander Duyck Message-ID: Date: Thu, 20 Sep 2018 17:16:22 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/20/2018 3:59 PM, Dan Williams wrote: > On Thu, Sep 20, 2018 at 3:31 PM Alexander Duyck > wrote: >> >> This patch is meant to force the device registration for nvdimm devices to >> be closer to the actual device. This is achieved by using either the NUMA >> node ID of the region, or of the parent. By doing this we can have >> everything above the region based on the region, and everything below the >> region based on the nvdimm bus. >> >> One additional change I made is that we hold onto a reference to the parent >> while we are going through registration. By doing this we can guarantee we >> can complete the registration before we have the parent device removed. >> >> By guaranteeing NUMA locality I see an improvement of as high as 25% for >> per-node init of a system with 12TB of persistent memory. >> >> Signed-off-by: Alexander Duyck >> --- >> drivers/nvdimm/bus.c | 19 +++++++++++++++++-- >> 1 file changed, 17 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c >> index 8aae6dcc839f..ca935296d55e 100644 >> --- a/drivers/nvdimm/bus.c >> +++ b/drivers/nvdimm/bus.c >> @@ -487,7 +487,9 @@ static void nd_async_device_register(void *d, async_cookie_t cookie) >> dev_err(dev, "%s: failed\n", __func__); >> put_device(dev); >> } >> + >> put_device(dev); >> + put_device(dev->parent); > > Good catch. The child does not pin the parent until registration, but > we need to make sure the parent isn't gone while were waiting for the > registration work to run. > > Let's break this reference count fix out into its own separate patch, > because this looks to be covering a gap that may need to be > recommended for -stable. Okay, I guess I can do that. > >> >> static void nd_async_device_unregister(void *d, async_cookie_t cookie) >> @@ -504,12 +506,25 @@ static void nd_async_device_unregister(void *d, async_cookie_t cookie) >> >> void __nd_device_register(struct device *dev) >> { >> + int node; >> + >> if (!dev) >> return; >> + >> dev->bus = &nvdimm_bus_type; >> + get_device(dev->parent); >> get_device(dev); >> - async_schedule_domain(nd_async_device_register, dev, >> - &nd_async_domain); >> + >> + /* >> + * For a region we can break away from the parent node, >> + * otherwise for all other devices we just inherit the node from >> + * the parent. >> + */ >> + node = is_nd_region(dev) ? to_nd_region(dev)->numa_node : >> + dev_to_node(dev->parent); > > Devices already automatically inherit the node of their parent, so I'm > not understanding why this is needed? That doesn't happen until you call device_add, which you don't call until nd_async_device_register. All that has been called on the device up to now is device_initialize which leaves the node at NUMA_NO_NODE.