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: <200710240219.25487.ioe-lkml@rameria.de>
Date:	Wed, 24 Oct 2007 02:19:23 +0200
From:	Ingo Oeser <ioe-lkml@...eria.de>
To:	Gregory Haskins <ghaskins@...ell.com>
Cc:	linux-rt-users@...r.kernel.org, linux-kernel@...r.kernel.org,
	Steven Rostedt <rostedt@...dmis.org>,
	Dmitry Adamushko <dmitry.adamushko@...il.com>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Ingo Molnar <mingo@...e.hu>, Darren Hart <dvhltc@...ibm.com>
Subject: Re: [PATCH 13/13] RT: Cache cpus_allowed weight for optimizing migration

Hi Gregory,

On Tuesday 23 October 2007, Gregory Haskins wrote:
> Calculating the weight is probably relatively expensive, so it is only
> done when the cpus_allowed mask is updated (which should be relatively
> infrequent, especially compared to scheduling frequency) and cached in
> the task_struct.

Why not make it a task flag, since according to your code, you are only 
interested whether this is <= 1 or > 1. Since !(x <= 1) <=> (x > 1)
for any given unsigned integer x, the required data structure is
a "boolean" or a flag.


Best Regards

Ingo Oeser
-
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/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ