From: "Dong, Eric" <eric.dong@intel.com>
To: "Brian J. Johnson" <brian.johnson@hpe.com>,
"Yao, Jiewen" <jiewen.yao@intel.com>,
"Ni, Ruiyu" <ruiyu.ni@intel.com>,
"edk2-devel@lists.01.org" <edk2-devel@lists.01.org>
Cc: Laszlo Ersek <lersek@redhat.com>
Subject: Re: [Patch 1/3] UefiCpuPkg/RegisterCpuFeaturesLib: Avoid AP calls PeiService.
Date: Fri, 21 Dec 2018 02:06:05 +0000 [thread overview]
Message-ID: <ED077930C258884BBCB450DB737E662259D64F2A@shsmsx102.ccr.corp.intel.com> (raw)
In-Reply-To: <993916e9-86cf-0e3c-19e4-b334de5214e7@hpe.com>
Hi,
Thanks all for your comments. It's valuable to me.
Seems like we all agree to remove the PcdSpinLockTimeout in AcquireSpinLock. I have submit BZ for it:
https://bugzilla.tianocore.org/show_bug.cgi?id=1419
For my patch, I will avoid this code change and set PcdSpinLockTimeout=0 for my modules. I will send V2 patch soon.
Thanks,
Eric
> -----Original Message-----
> From: Brian J. Johnson [mailto:brian.johnson@hpe.com]
> Sent: Friday, December 21, 2018 12:36 AM
> To: Yao, Jiewen <jiewen.yao@intel.com>; Ni, Ruiyu <ruiyu.ni@intel.com>;
> Dong, Eric <eric.dong@intel.com>; edk2-devel@lists.01.org
> Cc: Laszlo Ersek <lersek@redhat.com>
> 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 <eric.dong@intel.com>; Yao, Jiewen
> >> <jiewen.yao@intel.com>; edk2-devel@lists.01.org
> >> Cc: Laszlo Ersek <lersek@redhat.com>
> >> 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 <eric.dong@intel.com>
> >>> Sent: Thursday, December 20, 2018 9:23 AM
> >>> To: Yao, Jiewen <jiewen.yao@intel.com>; edk2-devel@lists.01.org
> >>> Cc: Ni, Ruiyu <ruiyu.ni@intel.com>; Laszlo Ersek <lersek@redhat.com>
> >>> 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 <eric.dong@intel.com>; edk2-devel@lists.01.org
> >>>> Cc: Ni, Ruiyu <ruiyu.ni@intel.com>; Laszlo Ersek
> >>>> <lersek@redhat.com>
> >>>> 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:edk2-devel-bounces@lists.01.org] On
> >>>>> Behalf Of Eric Dong
> >>>>> Sent: Thursday, December 20, 2018 9:16 AM
> >>>>> To: edk2-devel@lists.01.org
> >>>>> Cc: Ni, Ruiyu <ruiyu.ni@intel.com>; Laszlo Ersek
> >>>>> <lersek@redhat.com>
> >>>>> 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 <ruiyu.ni@intel.com>
> >>>>> Cc: Laszlo Ersek <lersek@redhat.com>
> >>>>> Contributed-under: TianoCore Contribution Agreement 1.1
> >>>>> Signed-off-by: Eric Dong <eric.dong@intel.com>
> >>>>> ---
> >>>>>
> >>>>> 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
> >>>>> edk2-devel@lists.01.org
> >>>>> https://lists.01.org/mailman/listinfo/edk2-devel
> > _______________________________________________
> > edk2-devel mailing list
> > edk2-devel@lists.01.org
> > https://lists.01.org/mailman/listinfo/edk2-devel
> >
>
>
> --
> Brian J. Johnson
> Enterprise X86 Lab
>
> Hewlett Packard Enterprise
>
> brian.johnson@hpe.com
next prev parent reply other threads:[~2018-12-21 2:06 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-20 1:15 [Patch 0/3] Avoid AP calls PeiService Eric Dong
2018-12-20 1:15 ` [Patch 1/3] UefiCpuPkg/RegisterCpuFeaturesLib: " Eric Dong
2018-12-20 1:19 ` Yao, Jiewen
2018-12-20 1:22 ` Dong, Eric
2018-12-20 2:06 ` Ni, Ruiyu
2018-12-20 2:08 ` Yao, Jiewen
2018-12-20 16:36 ` Brian J. Johnson
2018-12-21 2:06 ` Dong, Eric [this message]
2019-01-09 5:26 ` Dong, Eric
2019-01-09 10:35 ` Laszlo Ersek
2019-01-10 5:53 ` Dong, Eric
[not found] ` <734D49CCEBEEF84792F5B80ED585239D5BFAE3BF@SHSMSX103.ccr.corp.intel.com>
2019-01-10 12:51 ` Laszlo Ersek
2018-12-20 1:15 ` [Patch 2/3] " Eric Dong
2018-12-20 1:15 ` [Patch 3/3] UefiCpuPkg/RegisterCpuFeaturesLib: Remove useless function Eric Dong
2018-12-20 2:03 ` Ni, Ruiyu
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