Ersek, This updating prevents others to use MP protocol on multiple processors platform. I think another mail thread discussed solution could solve your performance issue.
If you cannot wait for it, could you introduce one MACRO in OvmfPkg DSC file temporary? Developer could pass its value by build command option to choose MP enable or disable. For example, !if $(YOUR_MACRO) == TRUE gUefiCpuPkgTokenSpaceGuid.PcdCpuMaxLogicalProcessorNumber|1 !endi Build -D YOUR_MACRO=TRUE Jeff -----Original Message----- From: Laszlo Ersek [mailto:ler...@redhat.com] Sent: Wednesday, November 26, 2014 11:43 PM To: Fan, Jeff; Chen, Fan; Justen, Jordan L Cc: Izumi, Taku; edk2-devel@lists.sourceforge.net Subject: Re: [edk2] [RFC PATCH V7 00/27] Introduce Mp Service protocol to UefiCpuPkg On 11/26/14 15:48, Laszlo Ersek wrote: > Hi, > > On 11/13/14 19:42, Jordan Justen wrote: >> On 2014-11-06 17:23:01, Fan, Jeff wrote: >>> Chen, >>> >>> Thanks your contribution. I will check-in your patch if there is no >>> further comments from other guys. >>> >>> Reviewed-by: Jeff Fan <jeff....@intel.com> >> >> Chen, >> >> I committed your series (r16345-r16371) for Jeff (to preserve the >> separate patches). >> >> Thanks for all your work on this! >> >> Let me know if you are interested in working on some follow up MP >> tasks. (I have 2 ideas. :) >> >> Jeff, >> >> Thanks for your review of this big series! > > I believe this series introduces an interesting performance > regression, at least when it is part of OVMF and runs on qemu/kvm. > > Now the APs seem to be spinning infinitely, for example while the user > is in the UEFI Setup utility. Before, there used to be no CPU load to > speak of, while the user was in the UEFI Setup utility. > > The useless spinning is quite bad: > - it hogs physical CPUs on the virtualization host for no good reason, > - it wastes electricity (problem for both laptops and data centers). > > Can we make this feature dependent on a Feature PCD? At the moment I > can't think of any workload I would run on the APs during runtime. No action needed; I realized there was a PCD already that allowed the user to control this feature at build time -- I solved it for myself with the attached patch. Thank you Laszlo ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk _______________________________________________ edk2-devel mailing list edk2-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/edk2-devel
