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
| ||
|
Date: Tue, 15 Dec 2020 09:46:51 +0530 From: Viresh Kumar <viresh.kumar@...aro.org> To: "Rafael J. Wysocki" <rjw@...ysocki.net> Cc: Linux PM <linux-pm@...r.kernel.org>, LKML <linux-kernel@...r.kernel.org>, Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>, Peter Zijlstra <peterz@...radead.org>, Doug Smythies <dsmythies@...us.net>, Giovanni Gherdovich <ggherdovich@...e.com> Subject: Re: [PATCH v2 0/3] cpufreq: Allow drivers to receive more information from the governor On 14-12-20, 21:01, Rafael J. Wysocki wrote: > Hi, > > The timing of this is not perfect (sorry about that), but here's a refresh > of this series. > > The majority of the previous cover letter still applies: > > On Monday, December 7, 2020 5:25:38 PM CET Rafael J. Wysocki wrote: > > > > This is based on the RFC posted a few days ago: > > > > https://lore.kernel.org/linux-pm/1817571.2o5Kk4Ohv2@kreacher/ > > > > Using intel_pstate in the passive mode with HWP enabled, in particular under > > the schedutil governor, is still kind of problematic, because it has to assume > > that it should not allow the frequency to fall below the one requested by the > > governor. For this reason, it translates the target frequency into HWP.REQ.MIN > > which generally causes the processor to run a bit too fast. > > > > Moreover, this allows the HWP algorithm to use any frequency between the target > > one and HWP.REQ.MAX that corresponds to the policy max limit and some workloads > > cause it to go for the max turbo frequency prematurely which hurts energy- > > efficiency without improving performance, even though the schedutil governor > > itself would not allow the frequency to ramp up so fast. > > > > This patch series attempts to improve the situation by introducing a new driver > > callback allowing the driver to receive more information from the governor. In > > particular, this allows the min (required) and target (desired) performance > > levels to be passed to it and those can be used to give better hints to the > > hardware. > > In this second revision there are three patches (one preparatory patch for > schedutil that hasn't changed since the v1, the introduction of the new > callback and schedutil changes in patch [2/3] and the intel_pstate changes > in patch [3/3] that are the same as before. > > Please see patch changelogs for details. Acked-by: Viresh Kumar <viresh.kumar@...aro.org> -- viresh
Powered by blists - more mailing lists