From: "Zeng, Star" <star.zeng@intel.com>
To: "Ni, Ray" <ray.ni@intel.com>,
"devel@edk2.groups.io" <devel@edk2.groups.io>
Cc: "Dong, Eric" <eric.dong@intel.com>,
"Lou, Yun" <yun.lou@intel.com>, Laszlo Ersek <lersek@redhat.com>,
"Zeng, Star" <star.zeng@intel.com>
Subject: Re: [PATCH] UefiCpuPkg/CpuFeature: reduce time complexty to calc CpuInfo.First
Date: Wed, 9 Dec 2020 08:48:40 +0000 [thread overview]
Message-ID: <DM6PR11MB4058A7B7913E77E445523C7CE3CC0@DM6PR11MB4058.namprd11.prod.outlook.com> (raw)
In-Reply-To: <20201208150142.1894-1-ray.ni@intel.com>
Only one minor comment inline, other parts look good to me.
> -----Original Message-----
> From: Ni, Ray <ray.ni@intel.com>
> Sent: Tuesday, December 8, 2020 11:02 PM
> To: devel@edk2.groups.io
> Cc: Dong, Eric <eric.dong@intel.com>; Zeng, Star <star.zeng@intel.com>;
> Lou, Yun <yun.lou@intel.com>; Laszlo Ersek <lersek@redhat.com>
> Subject: [PATCH] UefiCpuPkg/CpuFeature: reduce time complexty to calc
> CpuInfo.First
>
> CpuInfo.First stores whether the current thread belongs to the first
> package in the platform, first core in a package, first thread in a
> core.
>
> But the time complexity of original algorithm to calculate the
> CpuInfo.First is O (n) * O (p) * O (c).
> n: number of processors
> p: number of packages
> c: number of cores per package
>
> The patch trades time with space by storing the first package, first
> core per package, first thread per core in an array.
> The time complexity becomes O (n).
>
> Signed-off-by: Ray Ni <ray.ni@intel.com>
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Star Zeng <star.zeng@intel.com>
> Cc: Yun Lou <yun.lou@intel.com>
> Cc: Laszlo Ersek <lersek@redhat.com>
> ---
> .../CpuFeaturesInitialize.c | 87 ++++++++-----------
> 1 file changed, 36 insertions(+), 51 deletions(-)
>
> diff --git
> a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c
> b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c
> index d4a576385f..d21a1eaf38 100644
> --- a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c
> +++ b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c
> @@ -105,7 +105,10 @@ CpuInitDataInitialize (
> EFI_CPU_PHYSICAL_LOCATION *Location;
>
> UINT32 PackageIndex;
>
> UINT32 CoreIndex;
>
> - UINT32 First;
>
> + UINTN Pages;
>
> + UINT32 FirstPackage;
>
> + UINT32 *FirstCore;
>
> + UINT32 *FirstThread;
>
> ACPI_CPU_DATA *AcpiCpuData;
>
> CPU_STATUS_INFORMATION *CpuStatus;
>
> UINT32 *ThreadCountPerPackage;
>
> @@ -236,74 +239,56 @@ CpuInitDataInitialize (
>
>
> //
>
> // Initialize CpuFeaturesData->InitOrder[].CpuInfo.First
>
> + // Use AllocatePages () instead of AllocatePool () because pool cannot be
> freed in PEI phase but page can.
>
> //
>
> + Pages = EFI_SIZE_TO_PAGES (CpuStatus->PackageCount * sizeof
> (UINT32) + CpuStatus->PackageCount * CpuStatus->MaxCoreCount * sizeof
> (UINT32));
>
> + FirstCore = AllocatePages (Pages);
>
> + ASSERT (FirstCore != NULL);
>
> + FirstThread = FirstCore + CpuStatus->PackageCount;
>
> +
>
> + FirstPackage = MAX_UINT32;
>
> + for (PackageIndex = 0; PackageIndex < CpuStatus->PackageCount;
> PackageIndex++) {
>
> + FirstCore[PackageIndex] = MAX_UINT32;
>
> + for (CoreIndex = 0; CoreIndex < CpuStatus->MaxCoreCount; CoreIndex++)
> {
>
> + FirstThread[PackageIndex * CpuStatus->MaxCoreCount + CoreIndex] =
> MAX_UINT32;
>
> + }
>
> + }
Could this code block be replaced by a SetMem32(xxx, xxx, MAX_UINT32) call?
Thanks,
Star
>
>
>
> - //
>
> - // Set First.Package for each thread belonging to the first package.
>
> - //
>
> - First = MAX_UINT32;
>
> for (ProcessorNumber = 0; ProcessorNumber < NumberOfCpus;
> ProcessorNumber++) {
>
> Location = &CpuFeaturesData-
> >InitOrder[ProcessorNumber].CpuInfo.ProcessorInfo.Location;
>
> - First = MIN (Location->Package, First);
>
> +
>
> + FirstPackage = MIN (Location->Package, FirstPackage);
>
> + FirstCore[Location->Package] = MIN (Location->Core,
> FirstCore[Location->Package]);
>
> + FirstThread[Location->Package * CpuStatus->MaxCoreCount + Location-
> >Core] = MIN (
>
> + Location->Thread,
>
> + FirstThread[Location->Package * CpuStatus->MaxCoreCount +
> Location->Core]
>
> + );
>
> }
>
> +
>
> for (ProcessorNumber = 0; ProcessorNumber < NumberOfCpus;
> ProcessorNumber++) {
>
> Location = &CpuFeaturesData-
> >InitOrder[ProcessorNumber].CpuInfo.ProcessorInfo.Location;
>
> - if (Location->Package == First) {
>
> +
>
> + if (Location->Package == FirstPackage) {
>
> CpuFeaturesData->InitOrder[ProcessorNumber].CpuInfo.First.Package =
> 1;
>
> }
>
> - }
>
>
>
> - //
>
> - // Set First.Die/Tile/Module for each thread assuming:
>
> - // single Die under each package, single Tile under each Die, single Module
> under each Tile
>
> - //
>
> - for (ProcessorNumber = 0; ProcessorNumber < NumberOfCpus;
> ProcessorNumber++) {
>
> + //
>
> + // Set First.Die/Tile/Module for each thread assuming:
>
> + // single Die under each package, single Tile under each Die, single
> Module under each Tile
>
> + //
>
> CpuFeaturesData->InitOrder[ProcessorNumber].CpuInfo.First.Die = 1;
>
> CpuFeaturesData->InitOrder[ProcessorNumber].CpuInfo.First.Tile = 1;
>
> CpuFeaturesData->InitOrder[ProcessorNumber].CpuInfo.First.Module = 1;
>
> - }
>
>
>
> - for (PackageIndex = 0; PackageIndex < CpuStatus->PackageCount;
> PackageIndex++) {
>
> - //
>
> - // Set First.Core for each thread in the first core of each package.
>
> - //
>
> - First = MAX_UINT32;
>
> - for (ProcessorNumber = 0; ProcessorNumber < NumberOfCpus;
> ProcessorNumber++) {
>
> - Location = &CpuFeaturesData-
> >InitOrder[ProcessorNumber].CpuInfo.ProcessorInfo.Location;
>
> - if (Location->Package == PackageIndex) {
>
> - First = MIN (Location->Core, First);
>
> - }
>
> + if (Location->Core == FirstCore[Location->Package]) {
>
> + CpuFeaturesData->InitOrder[ProcessorNumber].CpuInfo.First.Core = 1;
>
> }
>
> -
>
> - for (ProcessorNumber = 0; ProcessorNumber < NumberOfCpus;
> ProcessorNumber++) {
>
> - Location = &CpuFeaturesData-
> >InitOrder[ProcessorNumber].CpuInfo.ProcessorInfo.Location;
>
> - if (Location->Package == PackageIndex && Location->Core == First) {
>
> - CpuFeaturesData->InitOrder[ProcessorNumber].CpuInfo.First.Core = 1;
>
> - }
>
> + if (Location->Thread == FirstThread[Location->Package * CpuStatus-
> >MaxCoreCount + Location->Core]) {
>
> + CpuFeaturesData->InitOrder[ProcessorNumber].CpuInfo.First.Thread =
> 1;
>
> }
>
> }
>
>
>
> - for (PackageIndex = 0; PackageIndex < CpuStatus->PackageCount;
> PackageIndex++) {
>
> - for (CoreIndex = 0; CoreIndex < CpuStatus->MaxCoreCount; CoreIndex++)
> {
>
> - //
>
> - // Set First.Thread for the first thread of each core.
>
> - //
>
> - First = MAX_UINT32;
>
> - for (ProcessorNumber = 0; ProcessorNumber < NumberOfCpus;
> ProcessorNumber++) {
>
> - Location = &CpuFeaturesData-
> >InitOrder[ProcessorNumber].CpuInfo.ProcessorInfo.Location;
>
> - if (Location->Package == PackageIndex && Location->Core ==
> CoreIndex) {
>
> - First = MIN (Location->Thread, First);
>
> - }
>
> - }
>
> -
>
> - for (ProcessorNumber = 0; ProcessorNumber < NumberOfCpus;
> ProcessorNumber++) {
>
> - Location = &CpuFeaturesData-
> >InitOrder[ProcessorNumber].CpuInfo.ProcessorInfo.Location;
>
> - if (Location->Package == PackageIndex && Location->Core ==
> CoreIndex && Location->Thread == First) {
>
> - CpuFeaturesData->InitOrder[ProcessorNumber].CpuInfo.First.Thread
> = 1;
>
> - }
>
> - }
>
> - }
>
> - }
>
> + FreePages (FirstCore, Pages);
>
> }
>
>
>
> /**
>
> --
> 2.27.0.windows.1
next prev parent reply other threads:[~2020-12-09 8:48 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-08 15:01 [PATCH] UefiCpuPkg/CpuFeature: reduce time complexty to calc CpuInfo.First Ni, Ray
2020-12-09 8:48 ` Zeng, Star [this message]
2020-12-11 10:39 ` Ni, Ray
2020-12-10 8:25 ` Laszlo Ersek
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