linux-kernel - Re: [PATCH 0/2] memory_hotplug: introduce config and command line options to set the default onlining policy

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 6 Apr 2016 11:53:34 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Vitaly Kuznetsov <vkuznets@...hat.com>
Cc:	linux-mm@...ck.org, linux-doc@...r.kernel.org,
	linux-kernel@...r.kernel.org, Jonathan Corbet <corbet@....net>,
	Dan Williams <dan.j.williams@...el.com>,
	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
	Mel Gorman <mgorman@...e.de>,
	David Vrabel <david.vrabel@...rix.com>,
	David Rientjes <rientjes@...gle.com>,
	Igor Mammedov <imammedo@...hat.com>,
	Lennart Poettering <lennart@...ttering.net>
Subject: Re: [PATCH 0/2] memory_hotplug: introduce config and command line
 options to set the default onlining policy

On Wed,  6 Apr 2016 15:45:10 +0200 Vitaly Kuznetsov <vkuznets@...hat.com> wrote:

> This patchset continues the work I started with:
> 
> commit 31bc3858ea3ebcc3157b3f5f0e624c5962f5a7a6
> Author: Vitaly Kuznetsov <vkuznets@...hat.com>
> Date:   Tue Mar 15 14:56:48 2016 -0700
> 
>     memory-hotplug: add automatic onlining policy for the newly added memory
> 
> Initially I was going to stop there and bring the policy setting logic to
> userspace. I met two issues on this way:
> 
> 1) It is possible to have memory hotplugged at boot (e.g. with QEMU). These
>    blocks stay offlined if we turn the onlining policy on by userspace.
> 
> 2) My attempt to bring this policy setting to systemd failed, systemd
>    maintainers suggest to change the default in kernel or ... to use tmpfiles.d
>    to alter the policy (which looks like a hack to me): 
>    https://github.com/systemd/systemd/pull/2938

That discussion really didn't come to a conclusion and I don't
understand why you consider Lennert's "recommended way" to be a hack?

> Here I suggest to add a config option to set the default value for the policy
> and a kernel command line parameter to make the override.

But the patchset looks pretty reasonable regardless of the above.