From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joao Martins Subject: Re: [PATCH v3] xen/acpi: upload _PSD info for non Dom0 CPUs too Date: Fri, 16 Mar 2018 13:57:13 +0000 Message-ID: References: <20180315142205.15839-1-joao.m.martins@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Boris Ostrovsky , linux-kernel@vger.kernel.org Cc: Juergen Gross , "Rafael J. Wysocki" , Len Brown , Robert Moore , Erik Schmauss , xen-devel@lists.xenproject.org, linux-acpi@vger.kernel.org, devel@acpica.org List-Id: linux-acpi@vger.kernel.org On 03/15/2018 03:45 PM, Boris Ostrovsky wrote: > On 03/15/2018 10:22 AM, Joao Martins wrote: >> All uploaded PM data from non-dom0 CPUs takes the info from vCPU 0 and >> changing only the acpi_id. For processors which P-state coordination type >> is HW_ALL (0xFD) it is OK to upload bogus P-state dependency information >> (_PSD), because Xen will ignore any cpufreq domains created for past CPUs. >> >> Albeit for platforms which expose coordination types as SW_ANY or SW_ALL, >> this will have some unintended side effects. Effectively, it will look at >> the P-state domain existence and *if it already exists* it will skip the >> acpi-cpufreq initialization and thus inherit the policy from the first CPU >> in the cpufreq domain. This will finally lead to the original cpu not >> changing target freq to P0 other than the first in the domain. Which will >> make turbo boost not getting enabled (e.g. for 'performance' governor) for >> all cpus. >> >> This patch fixes that, by also evaluating _PSD when we enumerate all ACPI >> processors and thus always uploading the correct info to Xen. We export >> acpi_processor_get_psd() for that this purpose, but change signature >> to not assume an existent of acpi_processor given that ACPI isn't creating >> an acpi_processor for non-dom0 CPUs. >> >> Signed-off-by: Joao Martins > > Reviewed-by: Boris Ostrovsky > Thanks! I suppose what's remaining is review (or ack) from ACPI folks on the interface changes made to acpi_processor_get_psd(). Joao