Hi all, We got some feedback about this BZ. Someone think this timeout is valuable for the debug purpose, and oppose to remove it. https://bugzilla.tianocore.org/show_bug.cgi?id=1419
So I'm back to here and want to still use this change. I not use "update PcdSpinLockTimeout to 0 in platform" solution because I think core driver depends on platform policy is not a good design. Do you guys have any other concern? Thanks, Eric > -----Original Message----- > From: Brian J. Johnson [mailto:[email protected]] > Sent: Friday, December 21, 2018 12:36 AM > To: Yao, Jiewen <[email protected]>; Ni, Ruiyu <[email protected]>; > Dong, Eric <[email protected]>; [email protected] > Cc: Laszlo Ersek <[email protected]> > Subject: Re: [edk2] [Patch 1/3] UefiCpuPkg/RegisterCpuFeaturesLib: Avoid > AP calls PeiService. > > Agreed. We've seen issues on real platforms with timed-out spinlocks in DXE > causing calls to GetPerformanceCounter and DebugAssert. (DXE has the > same code, with the same issues.) > > Note that it's possible to set PcdSpinLockTimeout=0 to work around the issue > on a particular platform, or in a particular module. But if you have to do > that > for every module which uses APs, and hence could contend for a spinlock, it > kind of defeats the point.... We're better off removing the timeout code. > > Thanks, > Brian > > On 12/19/18 8:08 PM, Yao, Jiewen wrote: > > Yes, I agree, if we don't have any real case. > > > > > >> -----Original Message----- > >> From: Ni, Ruiyu > >> Sent: Thursday, December 20, 2018 10:07 AM > >> To: Dong, Eric <[email protected]>; Yao, Jiewen > >> <[email protected]>; [email protected] > >> Cc: Laszlo Ersek <[email protected]> > >> Subject: RE: [edk2] [Patch 1/3] UefiCpuPkg/RegisterCpuFeaturesLib: > >> Avoid AP calls PeiService. > >> > >> Can you just change the AcquireSpinLock() behavior to remove the > >> Timeout PCD consumption? > >> > >> I haven't seen a real case that the timed acquisition of spin lock is > >> needed. > >> > >> > >> Thanks/Ray > >> > >>> -----Original Message----- > >>> From: Dong, Eric <[email protected]> > >>> Sent: Thursday, December 20, 2018 9:23 AM > >>> To: Yao, Jiewen <[email protected]>; [email protected] > >>> Cc: Ni, Ruiyu <[email protected]>; Laszlo Ersek <[email protected]> > >>> Subject: RE: [edk2] [Patch 1/3] UefiCpuPkg/RegisterCpuFeaturesLib: > >>> Avoid AP calls PeiService. > >>> > >>> > >>> Agreed, Maybe it's time to add a new API like > >>> AcquireSpinLockWithoutTimeOut? > >>> > >>> Thanks, > >>> Eric > >>>> -----Original Message----- > >>>> From: Yao, Jiewen > >>>> Sent: Thursday, December 20, 2018 9:19 AM > >>>> To: Dong, Eric <[email protected]>; [email protected] > >>>> Cc: Ni, Ruiyu <[email protected]>; Laszlo Ersek > >>>> <[email protected]> > >>>> Subject: RE: [edk2] [Patch 1/3] UefiCpuPkg/RegisterCpuFeaturesLib: > >>>> Avoid AP calls PeiService. > >>>> > >>>> Hi > >>>> If we think below code is generic, can we have an API for that? > >>>> > >>>> + // > >>>> + // Wait for the AP to release the MSR spin lock. > >>>> + // > >>>> + while (!AcquireSpinLockOrFail (&CpuFlags->ConsoleLogLock)) { > >>>> + CpuPause (); > >>>> + } > >>>> > >>>> > >>>> > >>>> > >>>>> -----Original Message----- > >>>>> From: edk2-devel [mailto:[email protected]] On > >>>>> Behalf Of Eric Dong > >>>>> Sent: Thursday, December 20, 2018 9:16 AM > >>>>> To: [email protected] > >>>>> Cc: Ni, Ruiyu <[email protected]>; Laszlo Ersek > >>>>> <[email protected]> > >>>>> Subject: [edk2] [Patch 1/3] UefiCpuPkg/RegisterCpuFeaturesLib: > >>>>> Avoid AP calls PeiService. > >>>>> > >>>>> In AcquireSpinLock function, it calls GetPerformanceCounter which > >>>>> final calls PeiService service. This patch avoid to call > >>>>> AcquireSpinLock function. > >>>>> > >>>>> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1411 > >>>>> > >>>>> Cc: Ruiyu Ni <[email protected]> > >>>>> Cc: Laszlo Ersek <[email protected]> > >>>>> Contributed-under: TianoCore Contribution Agreement 1.1 > >>>>> Signed-off-by: Eric Dong <[email protected]> > >>>>> --- > >>>>> > >>>>> UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c > >>>>> | > >>>>> 7 > >>>>> ++++++- > >>>>> 1 file changed, 6 insertions(+), 1 deletion(-) > >>>>> > >>>>> diff --git > >>>>> a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize. > >>>>> c > >>>>> b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize. > >>>>> c index 624ddee055..a64326239f 100644 > >>>>> --- > >>>>> a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize. > >>>>> c > >>>>> +++ > >> b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize. > >>>>> +++ c > >>>>> @@ -832,7 +832,12 @@ ProgramProcessorRegister ( > >>>>> RegisterTableEntry = &RegisterTableEntryHead[Index]; > >>>>> > >>>>> DEBUG_CODE_BEGIN (); > >>>>> - AcquireSpinLock (&CpuFlags->ConsoleLogLock); > >>>>> + // > >>>>> + // Wait for the AP to release the MSR spin lock. > >>>>> + // > >>>>> + while (!AcquireSpinLockOrFail (&CpuFlags->ConsoleLogLock)) { > >>>>> + CpuPause (); > >>>>> + } > >>>>> ThreadIndex = ApLocation->Package * > >> CpuStatus->MaxCoreCount * > >>>>> CpuStatus->MaxThreadCount + > >>>>> ApLocation->Core * CpuStatus->MaxThreadCount + > >>>>> ApLocation->Thread; > >>>>> -- > >>>>> 2.15.0.windows.1 > >>>>> > >>>>> _______________________________________________ > >>>>> edk2-devel mailing list > >>>>> [email protected] > >>>>> https://lists.01.org/mailman/listinfo/edk2-devel > > _______________________________________________ > > edk2-devel mailing list > > [email protected] > > https://lists.01.org/mailman/listinfo/edk2-devel > > > > > -- > Brian J. Johnson > Enterprise X86 Lab > > Hewlett Packard Enterprise > > [email protected] _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
