From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mel Gorman Subject: Re: [PATCH] cpufreq: intel_pstate: Limit the scope of HWP dynamic boost platforms Date: Tue, 31 Jul 2018 09:03:37 +0100 Message-ID: <20180731080337.nomq6pwophsvib4s@techsingularity.net> References: <20180730220029.81983-1-srinivas.pandruvada@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Return-path: Content-Disposition: inline In-Reply-To: <20180730220029.81983-1-srinivas.pandruvada@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org To: Srinivas Pandruvada Cc: lenb@kernel.org, rjw@rjwysocki.net, viresh.kumar@linaro.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, eero.t.tamminen@intel.com, ggherdovich@suse.cz, currojerez@riseup.net List-Id: linux-pm@vger.kernel.org On Mon, Jul 30, 2018 at 03:00:29PM -0700, Srinivas Pandruvada wrote: > Dynamic boosting of HWP performance on IO wake showed significant > improvement to IO workloads. This series was intended for Skylake Xeon > platforms only and feature was enabled by default based on CPU model > number. > > But some Xeon platforms reused the Skylake desktop CPU model number. This > caused some undesirable side effects to some graphics workloads. Since > they are heavily IO bound, the increase in CPU performance decreased the > power available for GPU to do its computing and hence decrease in graphics > benchmark performance. > > For example on a Skylake desktop, GpuTest benchmark showed average FPS > reduction from 529 to 506. > > This change makes sure that HWP boost feature is only enabled for Skylake > server platforms by using ACPI FADT preferred PM Profile. If some desktop > users wants to get benefit of boost, they can still enable boost from > intel_pstate sysfs attribute "hwp_dynamic_boost". > > Fixes: 41ab43c9c89e (cpufreq: intel_pstate: enable boost for Skylake Xeon) > Link: https://bugs.freedesktop.org/show_bug.cgi?id=107410 > Reported-by: Eero Tamminen > Signed-off-by: Srinivas Pandruvada Acked-by: Mel Gorman -- Mel Gorman SUSE Labs