linux-kernel - Re: [v3.10-rc] intel

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] [day] [month] [year] [list]

Message-ID: <CADDKRnAMyEud9RjCPN+1XsYC3SJbXF3N5OJ-v0g_J0p1TWyPBg@mail.gmail.com>
Date:	Wed, 29 May 2013 11:25:10 +0200
From:	Jörg Otte <jrg.otte@...il.com>
To:	Dirk Brandewie <dirk.brandewie@...il.com>
Cc:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	rafael.j.wysocki@...el.com
Subject: Re: [v3.10-rc] intel_pstate question

2013/5/28 Dirk Brandewie <dirk.brandewie@...il.com>:
> Hi Jörg,
>
>
> On 05/28/2013 08:02 AM, Jörg Otte wrote:
>>
>> Hi,
>>
>> the sysfs-interface of intel_pstate is different to that of the acpi
>> driver:
>> - intel_pstate shows current cpu-frequency in "cpuinfo_cur_freq" whereas
>>    the acpi counterpart uses "scaling_cur_freq".
>> - moreover cpuinfo_cur_freq is readable by root only, whereas
>>    scaling_cur_freq is world readable.
>>
>>    A monitoring tool must take care of theese differences.
>>    Is this intentional?
>>
>
> This is a side effect of the interface that intel_pstate presents to the
> cpufreq
> core.
>
> cpuinfo_cur_freq reports the value returned from the scaling driver.
>
> scaling_cur_freq reports the current frequency in the governors policy
> structure.
>
> intel_pstate has an internal governor so the core does not try to interpret
> the policy structure.
>
> I don't know why cpuinfo_cur_info is read-only root maybe Rafael knows the
> history.
>
Thank you Dirk, for the information!

Just another question: Now that processor 3a is supported, I am giving
pstate driver a try on my notebook. This is the first time I see frequencies
between above 2.5 and up to 3.1 GHz. With cpufreq driver I never saw that
frequencies.
So I think pstate driver uses turbo mode if appropriate (in contrast to
cpufreq). is this correct?

Thanks, Jörg
--
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/