linux-kernel - Re: [PATCH 14/16] KVM-GST: KVM Steal time registration

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]

Message-ID: <4D3E26E3.3000209@redhat.com>
Date:	Mon, 24 Jan 2011 20:26:59 -0500
From:	Rik van Riel <riel@...hat.com>
To:	Glauber Costa <glommer@...hat.com>
CC:	kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
	aliguori@...ibm.com,
	Jeremy Fitzhardinge <jeremy.fitzhardinge@...rix.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Avi Kivity <avi@...hat.com>
Subject: Re: [PATCH 14/16] KVM-GST: KVM Steal time registration

On 01/24/2011 08:25 PM, Glauber Costa wrote:
> On Mon, 2011-01-24 at 18:31 -0500, Rik van Riel wrote:
>> On 01/24/2011 01:06 PM, Glauber Costa wrote:
>>> Register steal time within KVM. Everytime we sample the steal time
>>> information, we update a local variable that tells what was the
>>> last time read. We then account the difference.
>>>
>>> Signed-off-by: Glauber Costa<glommer@...hat.com>
>>> CC: Rik van Riel<riel@...hat.com>
>>> CC: Jeremy Fitzhardinge<jeremy.fitzhardinge@...rix.com>
>>> CC: Peter Zijlstra<peterz@...radead.org>
>>> CC: Avi Kivity<avi@...hat.com>
>>
>> On second thought - how does this deal with cpu hotplug and
>> hot unplug?
>>
>> Do you allocate a new one of these structs every time a cpu
>> is hot unplugged and then hotplugged, leaking the old one?
>>
>> Will leaving the old value around confuse the steal time
>> calculation?
>
> If you look closely, there are no allocations happening at all,
> it's all static.

In that case, does the per-cpu steal area need to be
reinitialized at hotplug time?

-- 
All rights reversed
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/