On 11/04/16 09:18, Jeff Fan wrote:
> If MaxLogicalProcessorNumber is only 1, we needn't to wake up APs at all
> and needn't to register callback functions.
>
> It could improve boot performance on single supported system.
>
> https://bugzilla.tianocore.org/show_bug.cgi?id=204
>
> Cc: Feng Tian <feng.t...@intel.com>
> Cc: Liming Gao <liming....@intel.com>
> Cc: Michael Kinney <michael.d.kin...@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Jeff Fan <jeff....@intel.com>
> ---
> UefiCpuPkg/Library/MpInitLib/DxeMpLib.c | 7 ++++++
> UefiCpuPkg/Library/MpInitLib/MpLib.c | 39
> +++++++++++++++++++--------------
> UefiCpuPkg/Library/MpInitLib/PeiMpLib.c | 8 +++++++
> 3 files changed, 37 insertions(+), 17 deletions(-)
The MP services protocol and PPI that depend on this library will remain
available to callers, right?
Thanks
Laszlo
> diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
> b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
> index b399f1c..eb36d6f 100644
> --- a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
> +++ b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
> @@ -290,6 +290,13 @@ InitMpGlobalData (
>
> SaveCpuMpData (CpuMpData);
>
> + if (CpuMpData->CpuCount == 1) {
> + //
> + // If only BSP exists, return
> + //
> + return;
> + }
> +
> //
> // Avoid APs access invalid buff data which allocated by BootServices,
> // so we will allocate reserved data for AP loop code.
> diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c
> b/UefiCpuPkg/Library/MpInitLib/MpLib.c
> index 56b870e..a0edc55 100644
> --- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
> +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
> @@ -1143,6 +1143,7 @@ MpInitLibInitialize (
> } else {
> MaxLogicalProcessorNumber = OldCpuMpData->CpuCount;
> }
> + ASSERT (MaxLogicalProcessorNumber != 0);
>
> AsmGetAddressMap (&AddressMap);
> ApResetVectorSize = AddressMap.RendezvousFunnelSize + sizeof
> (MP_CPU_EXCHANGE_INFO);
> @@ -1209,10 +1210,12 @@ MpInitLibInitialize (
> MtrrGetAllMtrrs (&CpuMpData->MtrrTable);
>
> if (OldCpuMpData == NULL) {
> - //
> - // Wakeup all APs and calculate the processor count in system
> - //
> - CollectProcessorCount (CpuMpData);
> + if (MaxLogicalProcessorNumber > 1) {
> + //
> + // Wakeup all APs and calculate the processor count in system
> + //
> + CollectProcessorCount (CpuMpData);
> + }
> } else {
> //
> // APs have been wakeup before, just get the CPU Information
> @@ -1238,19 +1241,21 @@ MpInitLibInitialize (
> sizeof (CPU_VOLATILE_REGISTERS)
> );
> }
> - //
> - // Wakeup APs to do some AP initialize sync
> - //
> - WakeUpAP (CpuMpData, TRUE, 0, ApInitializeSync, CpuMpData);
> - //
> - // Wait for all APs finished initialization
> - //
> - while (CpuMpData->FinishedCount < (CpuMpData->CpuCount - 1)) {
> - CpuPause ();
> - }
> - CpuMpData->InitFlag = ApInitDone;
> - for (Index = 0; Index < CpuMpData->CpuCount; Index++) {
> - SetApState (&CpuMpData->CpuData[Index], CpuStateIdle);
> + if (MaxLogicalProcessorNumber > 1) {
> + //
> + // Wakeup APs to do some AP initialize sync
> + //
> + WakeUpAP (CpuMpData, TRUE, 0, ApInitializeSync, CpuMpData);
> + //
> + // Wait for all APs finished initialization
> + //
> + while (CpuMpData->FinishedCount < (CpuMpData->CpuCount - 1)) {
> + CpuPause ();
> + }
> + CpuMpData->InitFlag = ApInitDone;
> + for (Index = 0; Index < CpuMpData->CpuCount; Index++) {
> + SetApState (&CpuMpData->CpuData[Index], CpuStateIdle);
> + }
> }
> }
>
> diff --git a/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c
> b/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c
> index e242d37..1f2fcb8 100644
> --- a/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c
> +++ b/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c
> @@ -321,6 +321,14 @@ InitMpGlobalData (
> EFI_STATUS Status;
>
> SaveCpuMpData (CpuMpData);
> +
> + if (CpuMpData->CpuCount == 1) {
> + //
> + // If only BSP exists, return
> + //
> + return;
> + }
> +
> //
> // Register an event for EndOfPei
> //
>
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