From mboxrd@z Thu Jan  1 00:00:00 1970
Subject: Re: [edk2-devel] [PATCH v1 1/1] UefiCpuPkg: Remove PEI/DXE instances of CpuTimerLib.
To: Jason Lou <yun.lou@intel.com>,devel@edk2.groups.io
From: "Jason Lou" <yun.lou@intel.com>
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Date: Thu, 01 Apr 2021 01:41:41 -0700
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1. Since the time it takes to find specified GUID Extension Hob (CpuCrystal=
FrequencyHob: 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 global variable is shorter =
than it takes to calculate TSC
frequency with CPUID, but 450ns is really a short time, the impact on the =
platform is very limited.
In addition, in order to simplify the code, recommend using BaseCpuTimerLi=
b instead of DxeCpuTimerLib.

If anyone has questions or concerns, please feel free to let me know. If n=
ot, I will submit code patch later,
thanks.

Jason Lou

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<div>1. Since the time it takes to find specified GUID Extension Hob (CpuCr=
ystalFrequencyHob: about 2000ns) <br />is much longer than it takes to calc=
ulate TSC frequency with CPUID (about 450ns), I recommend using<br />BaseCp=
uTimerLib instead of PeiCpuTimerLib.<br /><br />2. The time it takes to get=
 TSC frequency from global variable is shorter than it takes to calculate T=
SC <br />frequency with CPUID, but 450ns is really a short time, the impact=
 on the platform is very limited.</div>
<div>In addition, in order to simplify the code, recommend using BaseCpuTi=
merLib instead of DxeCpuTimerLib.<br /><br />If anyone has questions or con=
cerns, please feel free to let me know. If not, I will submit code patch la=
ter,<br />thanks.<br /><br />Jason Lou<br /><br /></div>

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