linux-kernel - Re: [PATCH v2 1/2] cpumask: introduce cpumask for hotpluggable CPUs

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, 10 Aug 2011 22:53:31 +0200
From:	Daniel Lezcano <daniel.lezcano@...aro.org>
To:	Mike Turquette <mturquette@...com>
CC:	linux-kernel@...r.kernel.org, linux-pm@...ts.linux-foundation.org,
	gregkh@...e.de, linaro-dev@...ts.linaro.org, patches@...aro.org
Subject: Re: [PATCH v2 1/2] cpumask: introduce cpumask for hotpluggable CPUs

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 08/10/2011 10:03 PM, Mike Turquette wrote:
> On some platforms it is possible to have some CPUs which support CPU
> hotplug and some which do not.  Currently the prescence of an 'online'
> sysfs entry in userspace is adequate for applications to know that a CPU
> supports hotplug, but there is no convenient way to make the same
> determination in the kernel.
> 
> To better model this relationship this patch introduces a new cpumask to
> track CPUs that support CPU hotplug operations.
> 
> This new cpumask is populated at boot-time and remains static for the
> life of the machine.  Bits set in the mask indicate a CPU which supports
> hotplug, but make no guarantees about whether that CPU is currently
> online or not.  Likewise a cleared bit in the mask indicates either a
> CPU which cannot hotplug or a lack of a populated CPU.
> 
> The purpose of this new cpumask is to aid kernel code which uses CPU to
> take CPUs online and offline.  Possible uses are as a thermal event
> mitigation technique or as a power capping mechanism.
> 
> Signed-off-by: Mike Turquette <mturquette@...com>

Reviewed-by: Daniel Lezcano <daniel.lezcano@...aro.org>

- -- 
 <http://www.linaro.org/> Linaro.org ? Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

iQEcBAEBAgAGBQJOQu/KAAoJEAKBbMCpUGYAxnoH/0+WtrRGq0oOjkU8jIxzAEUP
OW6S7EQT13v97YapaEwUZpHOzrdeEa9bV5sVI3uc3H9n6dnQbh25eMuhiH/dTwF6
LHV1Tdv7/+ghiSc4NJunpXjAsObezUgTV9n2Zoip3kAfhMdV5DntJu0Izkdb5lkA
AD5CqV6oHqC0spa2/nMMeOYsdp3hLP3hA5wCyE8a2rxvbytxl2jRVommXOpF3AnI
s3OS7oyVFLpdvxVdAio1cXvM6vILtJFArAqw88AJUBsUsuehRxeOYVvTR3/z4RZD
LNEH72IkGY/8OVYp9/VoixWgWTUhXUR5BZwAjCP7a+xQk/1qK1LAM+/CXimwND0=
=90gJ
-----END PGP SIGNATURE-----
--
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/