linux-kernel - Re: [PATCH] Revert "cpufreq: pcc-cpufreq: update default value of cpuinfo_transition

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:	Fri, 22 Jul 2016 23:46:08 +0200
From:	"Rafael J. Wysocki" <rjw@...ysocki.net>
To:	Viresh Kumar <viresh.kumar@...aro.org>
Cc:	Andreas Herrmann <aherrmann@...e.com>,
	Jacob Tanenbaum <jtanenba@...hat.com>, stable@...r.kernel.org,
	linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] Revert "cpufreq: pcc-cpufreq: update default value of cpuinfo_transition_latency"

On Friday, July 22, 2016 02:28:52 PM Viresh Kumar wrote:
> On 22-07-16, 23:31, Rafael J. Wysocki wrote:
> > > cpufreq.c
> > > 
> > > 	if (policy->governor->max_transition_latency &&
> > > 	    policy->cpuinfo.transition_latency >
> > > 	    policy->governor->max_transition_latency) {
> > > 
> > > - And this check will always fail, unless max_transition_latency is zero.
> > 
> > Why would it fail?  If governor->max_transition_latency is non-zero, but less
> > than UNIT_MAX, the condition checked will be true to my eyes.
> 
> Bad wording. Sorry.
> 
> I meant, this 'if' check will always succeed (as you also noted), and
> so we will always get the error message reported in this patch.

Not always, but for drivers setting cpuinfo.transition_latency to CPUFREQ_ETERNAL.

Thanks,
Rafael