mirror of https://github.com/acidanthera/audk.git
a1c35ff312
REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2627 The commit will introduce a static PCD to specify the periodic interval for checking the AP status when MP services StartupAllAPs() and StartupThisAP() are being executed in a non-blocking manner. Or in other words, specifies the interval for callback function CheckApsStatus(). The purpose is to provide the platform owners with the ability to choose the proper interval value to trigger CheckApsStatus() according to: A) The number of processors in the system; B) How MP services (StartupAllAPs & StartupThisAP) being used. Setting the PCD to a small value means the AP status check callback will be triggered more frequently, it can benefit the performance for the case when the BSP uses WaitForEvent() or uses CheckEvent() in a loop to wait for AP(s) to complete the task, especially when the task can be finished considerably fast on AP(s). An example is within function CpuFeaturesInitialize() under UefiCpuPkg/Library/RegisterCpuFeaturesLib/DxeRegisterCpuFeaturesLib.c, where BSP will perform the same task with APs and requires all the processors to finish the task before BSP proceeds to its next task. Setting the PCD to a big value, on the other hand, can reduce the impact on BSP by the time being consumed in CheckApsStatus(), especially when the number of processors is huge so that the time consumed in CheckApsStatus() is not negligible. The type of the PCD is UINT32, which means the maximum possible interval value can be set to: 4,294,967,295 microseconds = 4,295 seconds = 71.58 minutes = 1.19 hours which should be sufficient for usage. For least impact, the default value of the new PCD will be the same with the current interval value. It will be set to 100,000 microseconds, which is 100 milliseconds. Unitest done: A) OS boot successfully; B) Use debug message to confirm the 'TriggerTime' parameter for the 'SetTimer' service is the same before & after this patch. Cc: Eric Dong <eric.dong@intel.com> Cc: Michael D Kinney <michael.d.kinney@intel.com> Cc: Brian J. Johnson <brian.johnson@hpe.com> Signed-off-by: Hao A Wu <hao.a.wu@intel.com> Reviewed-by: Star Zeng <star.zeng@intel.com> Reviewed-by: Ray Ni <ray.ni@intel.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> |
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| .. | ||
| BaseUefiCpuLib | ||
| BaseXApicLib | ||
| BaseXApicX2ApicLib | ||
| CpuCommonFeaturesLib | ||
| CpuExceptionHandlerLib | ||
| CpuTimerLib | ||
| MpInitLib | ||
| MpInitLibUp | ||
| MtrrLib | ||
| PlatformSecLibNull | ||
| RegisterCpuFeaturesLib | ||
| SecPeiDxeTimerLibUefiCpu | ||
| SmmCpuFeaturesLib | ||
| SmmCpuPlatformHookLibNull | ||