From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt1-f198.google.com (mail-qt1-f198.google.com [209.85.160.198]) by kanga.kvack.org (Postfix) with ESMTP id DBF2A6B3053 for ; Fri, 23 Nov 2018 07:58:22 -0500 (EST) Received: by mail-qt1-f198.google.com with SMTP id u32so8757931qte.1 for ; Fri, 23 Nov 2018 04:58:22 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id h7si5549547qkb.218.2018.11.23.04.58.22 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 23 Nov 2018 04:58:22 -0800 (PST) Subject: Re: [PATCH v1] mm/memory_hotplug: drop "online" parameter from add_memory_resource() References: <20181123123740.27652-1-david@redhat.com> <20181123125400.GL8625@dhcp22.suse.cz> From: David Hildenbrand Message-ID: Date: Fri, 23 Nov 2018 13:58:16 +0100 MIME-Version: 1.0 In-Reply-To: <20181123125400.GL8625@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, Boris Ostrovsky , Juergen Gross , Stefano Stabellini , Andrew Morton , Dan Williams , Oscar Salvador , Pavel Tatashin , Joonsoo Kim , Arun KS , Mathieu Malaterre , Stephen Rothwell On 23.11.18 13:54, Michal Hocko wrote: > On Fri 23-11-18 13:37:40, David Hildenbrand wrote: >> User space should always be in charge of how to online memory and >> if memory should be onlined automatically in the kernel. Let's drop the >> parameter to overwrite this - XEN passes memhp_auto_online, just like >> add_memory(), so we can directly use that instead internally. > > Heh, I wanted to get rid of memhp_auto_online so much and now we have it > in the core memory_hotplug. Not a win on my side I would say :/ That is actually a good point: Can we remove memhp_auto_online or is it already some sort of kernel ABI? (as it is exported via /sys/devices/system/memory/auto_online_blocks) > On the other hand this can be seen as a cleanup because it removes that > ambiguity that some callers might be unaware of the memhp_auto_online > leading to a different behavior. I would say this patch is a step into the right direction - remove the flag from the interfaces, then drop it (eventually, as stated not sure if that train has left the station). > >> Cc: Boris Ostrovsky >> Cc: Juergen Gross >> Cc: Stefano Stabellini >> Cc: Andrew Morton >> Cc: Dan Williams >> Cc: Oscar Salvador >> Cc: Pavel Tatashin >> Cc: Michal Hocko >> Cc: David Hildenbrand >> Cc: Joonsoo Kim >> Cc: Arun KS >> Cc: Mathieu Malaterre >> Cc: Stephen Rothwell >> Signed-off-by: David Hildenbrand > > Acked-by: Michal Hocko > -- Thanks, David / dhildenb