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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 5881BC169C4 for ; Wed, 6 Feb 2019 20:07:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2387520844 for ; Wed, 6 Feb 2019 20:07:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727139AbfBFUHl (ORCPT ); Wed, 6 Feb 2019 15:07:41 -0500 Received: from foss.arm.com ([217.140.101.70]:57800 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726401AbfBFUHl (ORCPT ); Wed, 6 Feb 2019 15:07:41 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1EFAF80D; Wed, 6 Feb 2019 12:07:41 -0800 (PST) Received: from [192.168.1.123] (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 87B063F719; Wed, 6 Feb 2019 12:07:39 -0800 (PST) Subject: Re: [PATCH] mm/memory-hotplug: Add sysfs hot-remove trigger To: Greg KH Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, rafael@kernel.org, mhocko@kernel.org, akpm@linux-foundation.org References: <29ed519902512319bcc62e071d52b712fa97e306.1549469965.git.robin.murphy@arm.com> <20190206184544.GA12326@kroah.com> From: Robin Murphy Message-ID: Date: Wed, 6 Feb 2019 20:07:28 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:60.0) Gecko/20100101 Thunderbird/60.5.0 MIME-Version: 1.0 In-Reply-To: <20190206184544.GA12326@kroah.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019-02-06 6:45 pm, Greg KH wrote: > On Wed, Feb 06, 2019 at 05:03:53PM +0000, Robin Murphy wrote: >> ARCH_MEMORY_PROBE is a useful thing for testing and debugging hotplug, >> but being able to exercise the (arguably trickier) hot-remove path would >> be even more useful. Extend the feature to allow removal of offline >> sections to be triggered manually to aid development. >> >> Signed-off-by: Robin Murphy >> --- >> >> This is inspired by a previous proposal[1], but in coming up with a >> more robust interface I ended up rewriting the whole thing from >> scratch. The lack of documentation is semi-deliberate, since I don't >> like the idea of anyone actually relying on this interface as ABI, but >> as a handy tool it felt useful enough to be worth sharing :) >> >> Robin. >> >> [1] https://lore.kernel.org/lkml/22d34fe30df0fbacbfceeb47e20cb1184af73585.1511433386.git.ar@linux.vnet.ibm.com/ >> >> drivers/base/memory.c | 42 +++++++++++++++++++++++++++++++++++++++++- >> 1 file changed, 41 insertions(+), 1 deletion(-) > > You have to add new Documentation/ABI entries for each new sysfs file > you add :( Ah, the documentation provided is adapted from the documentation for the existing "probe" attribute it builds upon ;) But yeah, perhaps I should have tagged this post as an RFC. Much as I dislike it being anywhere near an ABI, if everyone thinks the feature is merge-worthy I'll go ahead and write up some proper doc entries too. Robin.