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audk/MdePkg/Library/BaseLib
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Ankur Arora 4bf2a5b045 MdePkg: use CpuPause() in CpuDeadLoop() 
CpuPause() might allow the CPU to go into a lower power state
state while we spin.

On X86, CpuPause() executes a PAUSE instruction which the Intel
and AMD specs describe as follows:

Intel:
  "PAUSE: An additional function of the PAUSE instruction is to reduce
  the power consumed by a processor while executing a spin loop. A
  processor can execute a spin-wait loop extremely quickly, causing the
  processor to consume a lot of power while it waits for the resource it
  is spinning on to become available. Inserting a pause instruction in a
  spin-wait loop greatly reduces the processor?s power consumption."

AMD:
  "PAUSE: Improves the performance of spin loops, by providing a hint to
  the processor that the current code is in a spin loop. The processor
  may use this to optimize power consumption while in the spin loop.
  Architecturally, this instruction behaves like a NOP instruction."

On RISC-V and ARM64, CpuPause() executes a NOP, which is no worse than
the tight loop we have.

Cc: Liming Gao <gaoliming@byosoft.com.cn>
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
 		2021-03-25 03:40:17 +00:00
..
AArch64 MdePkg/BaseLib: Fix invalid memory access in AArch64 SetJump/LongJump 2020-10-13 03:20:49 +00:00
Arm MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
Ebc MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
Ia32 MdePkg/BaseLib: Add support for the VMGEXIT instruction 2020-08-16 16:45:42 +00:00
RiscV64 BaseLib:Fix RISC-V Supervisor mode (S-Mode) trap handler reentry issue. 2020-08-12 04:01:39 +00:00
X64 MdePkg/BaseLib: Add support for the VMGEXIT instruction 2020-08-16 16:45:42 +00:00
ARShiftU64.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
BaseLib.inf MdePkg/BaseLib: Add support for the VMGEXIT instruction 2020-08-16 16:45:42 +00:00
BaseLib.uni MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
BaseLibInternals.h MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
BitField.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
CheckSum.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
ChkStkGcc.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
Cpu.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
CpuDeadLoop.c MdePkg: use CpuPause() in CpuDeadLoop() 2021-03-25 03:40:17 +00:00
DivS64x64Remainder.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
DivU64x32.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
DivU64x32Remainder.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
DivU64x64Remainder.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
FilePaths.c MdePkg: Fix spelling mistake for occurred 2020-08-19 00:54:23 +00:00
GetPowerOfTwo32.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
GetPowerOfTwo64.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
HighBitSet32.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
HighBitSet64.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
LRotU32.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
LRotU64.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
LShiftU64.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
LinkedList.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
LongJump.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
LowBitSet32.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
LowBitSet64.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
Math64.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
ModU64x32.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
MultS64x64.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
MultU64x32.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
MultU64x64.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
RRotU32.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
RRotU64.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
RShiftU64.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
SafeString.c MdePkg: Fix SafeString performing assertions on runtime checks 2020-05-22 00:03:14 +00:00
SetJump.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
String.c MdePkg: Remove code wrapped by DISABLE_NEW_DEPRECATED_INTERFACES 2020-10-13 01:35:03 +00:00
SwapBytes16.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
SwapBytes32.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
SwapBytes64.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
SwitchStack.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
Unaligned.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
UnitTestHost.c MdePkg/Library/BaseLib: Add BaseLib instance for host based unit tests 2020-07-15 05:25:21 +00:00
UnitTestHost.h MdePkg/Library/BaseLib: Add BaseLib instance for host based unit tests 2020-07-15 05:25:21 +00:00
UnitTestHostBaseLib.inf MdePkg/Library/UnitTestHostBaseLib: Add missing services 2020-07-28 19:03:09 +00:00
UnitTestHostBaseLib.uni MdePkg/Library/BaseLib: Add BaseLib instance for host based unit tests 2020-07-15 05:25:21 +00:00
X86DisablePaging32.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
X86DisablePaging64.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
X86EnablePaging32.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
X86EnablePaging64.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
X86FxRestore.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
X86FxSave.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
X86GetInterruptState.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
X86MemoryFence.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
X86Msr.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
X86PatchInstruction.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
X86RdRand.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
X86ReadGdtr.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
X86ReadIdtr.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
X86SpeculationBarrier.c MdePkg/BaseLib: Use PcdSpeculationBarrierType 2019-04-30 16:39:15 -07:00
X86Thunk.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
X86UnitTestHost.c MdePkg/Library/BaseLib: Add BaseLib instance for host based unit tests 2020-07-15 05:25:21 +00:00
X86WriteGdtr.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
X86WriteIdtr.c MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00