1. Since the time it takes to find specified GUID Extension Hob
(CpuCrystalFrequencyHob: about 2000ns)
is much longer than it takes to calculate TSC frequency with CPUID (about
450ns), I recommend using
BaseCpuTimerLib instead of PeiCpuTimerLib.
2. The time it takes to get TSC frequency from
Hi Star, sorry for my late response.
Yes, HOB search time is related to the sequence of HOB generation.
Some data collected on the test platform:
1. The time range required to search for the specified HOB: 20ns ~ 2700ns
Search for the 1st HOB(PHIT HOB): 20ns
Search for the last HOB: about 2700ns
Ersek
Sent: Friday, September 25, 2020 2:46 PM
To: Ni, Ray ; Lou, Yun ;
devel@edk2.groups.io
Cc: Dong, Eric ; Kumar, Rahul1
Subject: Re: [edk2-devel] [PATCH v1 1/1] UefiCpuPkg: Remove PEI/DXE instances
of CpuTimerLib.
On 09/25/20 07:25, Ni, Ray wrote:
> Reviewed-by: Ray Ni
Acked-by:
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2832
1. Remove PEI instance(PeiCpuTimerLib).
PeiCpuTimerLib is currently designed to save time by getting CPU TSC frequncy
from Hob.
BaseCpuTimerLib is designed to calculate TSC frequency by using CPUID[15h] each
time.
The time it takes to
On 09/25/20 07:25, Ni, Ray wrote:
> Reviewed-by: Ray Ni
Acked-by: Laszlo Ersek
Thanks
Laszlo
>
>> -Original Message-
>> From: Lou, Yun
>> Sent: Friday, September 25, 2020 11:58 AM
>> To: devel@edk2.groups.io
>> Cc: Lou, Yun ; Ni, Ray ; Dong, Eric
>> ; Laszlo Ersek
>> ; Kumar,
Reviewed-by: Ray Ni
> -Original Message-
> From: Lou, Yun
> Sent: Friday, September 25, 2020 11:58 AM
> To: devel@edk2.groups.io
> Cc: Lou, Yun ; Ni, Ray ; Dong, Eric
> ; Laszlo Ersek
> ; Kumar, Rahul1
> Subject: [PATCH v1 1/1] UefiCpuPkg: Remove PEI/DXE instances of CpuTimerLib.
>
>
