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=-8.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 6CFBCC3A5A5 for ; Thu, 5 Sep 2019 09:02:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4251F2053B for ; Thu, 5 Sep 2019 09:02:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567674175; bh=mmdFor1PcuA/NKVn/lYFZyPn01kc0gzg6HNtEancJ78=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=c2xnaOWTm1mjkO6ncCOU8Z33vDNhRCCL+dmDxZs4DQGTiY2sHUPH/ExkdnN/hnCfY pYJqjEHDb3UJStbQ/NUVK8qQCFcsh7iGp0YMfM77sNknPqE5nNTy76pnvlRlDGLX3n ENOwbT8wWu/n5WpHuTskCvu/o4KNfhbbw1JH0c4s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732944AbfIEJCy (ORCPT ); Thu, 5 Sep 2019 05:02:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:57298 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726231AbfIEJCy (ORCPT ); Thu, 5 Sep 2019 05:02:54 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6DA1C21743; Thu, 5 Sep 2019 09:02:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567674172; bh=mmdFor1PcuA/NKVn/lYFZyPn01kc0gzg6HNtEancJ78=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=d8q30NhyqU9VGgtV02UIjQm6Bg813ked4SuWBacps7edAqTUIH4GsWYwnLZbXHb+3 nbs5QMAGwuGdRHh1V6L2hOX/8am3+Bvc7MKbURzlCMO3Wa9go4BO/6gS3n58HyRaDX VWMVUrP1luxySIjBuCrHztG2DjUnBfVNbHHuLz20= Date: Thu, 5 Sep 2019 11:02:49 +0200 From: Greg KH To: Yunsheng Lin Cc: rafael@kernel.org, linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@kernel.org, mhocko@kernel.org, linuxarm@huawei.com Subject: Re: [PATCH RFC] driver core: ensure a device has valid node id in device_add() Message-ID: <20190905090249.GA28356@kroah.com> References: <1567647230-166903-1-git-send-email-linyunsheng@huawei.com> <20190905055727.GB23826@kroah.com> <20190905073334.GA29933@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 05, 2019 at 04:57:00PM +0800, Yunsheng Lin wrote: > On 2019/9/5 15:33, Greg KH wrote: > > On Thu, Sep 05, 2019 at 02:48:24PM +0800, Yunsheng Lin wrote: > >> On 2019/9/5 13:57, Greg KH wrote: > >>> On Thu, Sep 05, 2019 at 09:33:50AM +0800, Yunsheng Lin wrote: > >>>> Currently a device does not belong to any of the numa nodes > >>>> (dev->numa_node is NUMA_NO_NODE) when the FW does not provide > >>>> the node id and the device has not no parent device. > >>>> > >>>> According to discussion in [1]: > >>>> Even if a device's numa node is not set by fw, the device > >>>> really does belong to a node. > >>>> > >>>> This patch sets the device node to node 0 in device_add() if > >>>> the fw has not specified the node id and it either has no > >>>> parent device, or the parent device also does not have a valid > >>>> node id. > >>>> > >>>> There may be explicit handling out there relying on NUMA_NO_NODE, > >>>> like in nvme_probe(). > >>>> > >>>> [1] https://lkml.org/lkml/2019/9/2/466 > >>>> > >>>> Signed-off-by: Yunsheng Lin > >>>> --- > >>>> drivers/base/core.c | 17 ++++++++++++++--- > >>>> include/linux/numa.h | 2 ++ > >>>> 2 files changed, 16 insertions(+), 3 deletions(-) > >>>> > >>>> diff --git a/drivers/base/core.c b/drivers/base/core.c > >>>> index 1669d41..466b8ff 100644 > >>>> --- a/drivers/base/core.c > >>>> +++ b/drivers/base/core.c > >>>> @@ -2107,9 +2107,20 @@ int device_add(struct device *dev) > >>>> if (kobj) > >>>> dev->kobj.parent = kobj; > >>>> > >>>> - /* use parent numa_node */ > >>>> - if (parent && (dev_to_node(dev) == NUMA_NO_NODE)) > >>>> - set_dev_node(dev, dev_to_node(parent)); > >>>> + /* use parent numa_node or default node 0 */ > >>>> + if (!numa_node_valid(dev_to_node(dev))) { > >>>> + int nid = parent ? dev_to_node(parent) : NUMA_NO_NODE; > >>> > >>> Can you expand this to be a "real" if statement please? > >> > >> Sure. May I ask why "? :" is not appropriate here? > > > > Because it is a pain to read, just spell it out and make it obvious what > > is happening. You write code for developers first, and the compiler > > second, and in this case, either way is identical to the compiler. > > > >>>> + > >>>> + if (numa_node_valid(nid)) { > >>>> + set_dev_node(dev, nid); > >>>> + } else { > >>>> + if (nr_node_ids > 1U) > >>>> + pr_err("device: '%s': has invalid NUMA node(%d)\n", > >>>> + dev_name(dev), dev_to_node(dev)); > >>> > >>> dev_err() will show you the exact device properly, instead of having to > >>> rely on dev_name(). > >>> > >>> And what is a user to do if this message happens? How do they fix this? > >>> If they can not, what good is this error message? > >> > >> If user know about their system's topology well enough and node 0 > >> is not the nearest node to the device, maybe user can readjust that by > >> writing the nearest node to /sys/class/pci_bus/XXXX/device/numa_node, > >> if not, then maybe user need to contact the vendor for info or updates. > >> > >> Maybe print error message as below: > >> > >> dev_err(dev, FW_BUG "has invalid NUMA node(%d). Readjust it by writing to sysfs numa_node or contact your vendor for updates.\n", > >> dev_to_node(dev)); > > > > FW_BUG? > > The sysfs numa_node writing interface does print FW_BUG error. > Maybe it is a way of telling the user to contact the vendors, which > pushing the vendors to update the FW. But is this always going to be caused by a firmware bug? If so, ok, if not, and it's a driver/bus kernel issue, we should not say this. thanks, greg k-h