mirror of https://github.com/acidanthera/audk.git
c6be6dab9c
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3179 When BSP first time wakes all APs, each AP atomically increases CpuMpData->CpuCount and CpuMpData->FinishedCount. Each AP atomically increases CpuMpData->NumApsExecuting in early assembly code and decreases it before it enters to HLT or MWAIT state. Putting them together, the 3 variables are changed in the following order: 1. NumApsExecuting++ // in assembly 2. CpuCpunt++ 4. FinishedCount++ 3. NumApsExecuting-- // in C BSP waits for a certain timeout and then polls NumApsExecuting until it drops to zero. It assumes all APs are waken up concurrently and NumApsExecuting only drops to zero when all APs have checked in. Then it additionally waits for FinishedCount == CpuCount - 1. (FinishedCount doesn't include BSP while CpuCount includes BSP.) There is no need to additionally wait for FinishedCount == CpuCount - 1 because when NumApsExecuting == 0, the number of increament of FinishedCount and CpuCount should equal. This patch simplifies the code to remove "CpuCount++" in ApWakeupFunction() and assigns FinishedCount + 1 to CpuCount after WakeUpAP(). Signed-off-by: Ray Ni <ray.ni@intel.com> Reviewed-by: Eric Dong <eric.dong@intel.com> Acked-by: Laszlo Ersek <lersek@redhat.com> |
||
|---|---|---|
| .. | ||
| Ia32 | ||
| X64 | ||
| DxeMpInitLib.inf | ||
| DxeMpInitLib.uni | ||
| DxeMpLib.c | ||
| Microcode.c | ||
| MpLib.c | ||
| MpLib.h | ||
| PeiMpInitLib.inf | ||
| PeiMpInitLib.uni | ||
| PeiMpLib.c | ||