> On Jun 5, 2015, at 4:29 PM, Andrew Fish <af...@apple.com> wrote: > > >> On Jun 5, 2015, at 4:21 PM, Andrew Fish <af...@apple.com >> <mailto:af...@apple.com>> wrote: >> >> >>> On Jun 5, 2015, at 4:13 PM, Saiprasad Chavali <s...@marvell.com >>> <mailto:s...@marvell.com>> wrote: >>> >>> Hi Andrew, >>> >>> The “GetPerformanceCounter” is not working the way we want, the elapsed >>> time varies, often from incremental value to decremented value. >>> > > For example the ACPI Timer version of the Timer lib rolls over every 3.54 > seconds. You may need a TSC version of the TimerLib to get good timing data. >
https://svn.code.sf.net/p/edk2/code/trunk/edk2/DuetPkg/Library/DuetTimerLib/X86TimerLib.c UINT64 EFIAPI GetPerformanceCounterProperties ( OUT UINT64 *StartValue, OPTIONAL OUT UINT64 *EndValue OPTIONAL ) { if (InternalGetApciDescrptionTable() == NULL) { return 0; } if (StartValue != NULL) { *StartValue = 0; } if (EndValue != NULL) { *EndValue = (1 << gAcpiDesc->PM_TMR_BLK.RegisterBitWidth) - 1; } return 3579545; } You may need to use an instance of the TimerLib that uses the X86 TSC, to get better quality performance profiling. https://svn.code.sf.net/p/edk2/code/trunk/edk2/PerformancePkg/Library/TscTimerLib/ Thanks, Andrew Fish > Thanks, > > Andrew Fish > >>> For example: I save the start time with a call to the API and periodically >>> I call the API for End time. Measure the difference, with a time out >>> value. It fails >>> >>> Observation, with repeated calls to “GetPerformancecounter” the value >>> returned, varies from high value to low than the saved Start Time. I don’t >>> think this will work for us. >>> >>> We need a value that increments in time like a system time call in windows >>> “getsystemtime” in msecs. >>> >>> Please suggest. >>> >> >> You need the correct TimerLib for your hardware. What TimerLib are you >> using? >> >> Thanks, >> >> Andrew Fish >> >>> Thanks >>> Sai >>> >>> From: Saiprasad Chavali >>> Sent: Wednesday, June 03, 2015 9:49 PM >>> To: edk2-devel@lists.sourceforge.net >>> <mailto:edk2-devel@lists.sourceforge.net> >>> Subject: RE: [edk2] getsystemtime-- help >>> >>> Thanks Andrew, will try with “GetPerformanceCounter” and see how this works >>> out. >>> The test bed at present is x86 >>> >>> Sai >>> >>> From: Andrew Fish [mailto:af...@apple.com <mailto:af...@apple.com>] >>> Sent: Wednesday, June 03, 2015 9:28 PM >>> To: edk2-devel@lists.sourceforge.net >>> <mailto:edk2-devel@lists.sourceforge.net> >>> Subject: Re: [edk2] getsystemtime-- help >>> >>> >>> On Jun 3, 2015, at 9:22 PM, Saiprasad Chavali <s...@marvell.com >>> <mailto:s...@marvell.com>> wrote: >>> >>> Hi Andrew, >>> >>> Trying to measure the elapsed time interval with a call to system time at >>> different levels. >>> >>> >>> If you are writing platform code, or you know the platform. >>> >>> https://svn.code.sf.net/p/edk2/code/trunk/edk2/MdePkg/Include/Library/PerformanceLib.h >>> >>> <https://svn.code.sf.net/p/edk2/code/trunk/edk2/MdePkg/Include/Library/PerformanceLib.h> >>> Which a lot of times is built on: >>> https://svn.code.sf.net/p/edk2/code/trunk/edk2/MdePkg/Include/Library/TimerLib.h >>> >>> <https://svn.code.sf.net/p/edk2/code/trunk/edk2/MdePkg/Include/Library/TimerLib.h> >>> >>> On a PC the PerformanceCounter is usually the TSC (CPU register) or the >>> ACPI Timer. >>> >>> Thanks, >>> >>> Andrew Fish >>> >>> >>> Thanks >>> Sai >>> >>> From: Andrew Fish [mailto:af...@apple.com <mailto:af...@apple.com>] >>> Sent: Wednesday, June 03, 2015 7:51 PM >>> To: edk2-devel@lists.sourceforge.net >>> <mailto:edk2-devel@lists.sourceforge.net> >>> Subject: Re: [edk2] getsystemtime-- help >>> >>> >>> On Jun 3, 2015, at 7:47 PM, Saiprasad Chavali <s...@marvell.com >>> <mailto:s...@marvell.com>> wrote: >>> >>> Hi Andrew, >>> >>> Thanks for the comment, is there way we can ping the RTC with the help of >>> architecture protocol, at higher TPL’s than Callback (or) nothing? >>> >>> >>> The rules are the rules. >>> >>> What are you trying to do? >>> >>> Thanks, >>> >>> Andrew Fish >>> >>> >>> >>> Sai >>> >>> From: Andrew Fish [mailto:af...@apple.com <mailto:af...@apple.com>] >>> Sent: Wednesday, June 03, 2015 7:40 PM >>> To: edk2-devel@lists.sourceforge.net >>> <mailto:edk2-devel@lists.sourceforge.net> >>> Subject: Re: [edk2] getsystemtime-- help >>> >>> >>> On Jun 3, 2015, at 7:27 PM, Saiprasad Chavali <s...@marvell.com >>> <mailto:s...@marvell.com>> wrote: >>> >>> HI, >>> >>> Is there a better way to obtain the system time? I tried GetTime and the >>> call hangs When I raise the TPL level. >>> >>> >>> Did you violate the TPL rules in the UEFI spec? >>> >>> UEFI 2.5 section 6.1Table 23. TPL Restrictions >>> Time Services <= TPL_CALLBACK >>> >>> If not it is a bug in the implementation of gRT->GetTime(). >>> >>> Thanks, >>> >>> Andrew Fish >>> >>> >>> >>> >>> Thanks >>> Sai >>> ------------------------------------------------------------------------------ >>> _______________________________________________ >>> edk2-devel mailing list >>> edk2-devel@lists.sourceforge.net <mailto:edk2-devel@lists.sourceforge.net> >>> https://lists.sourceforge.net/lists/listinfo/edk2-devel >>> <https://lists.sourceforge.net/lists/listinfo/edk2-devel> >>> >>> ------------------------------------------------------------------------------ >>> _______________________________________________ >>> edk2-devel mailing list >>> edk2-devel@lists.sourceforge.net <mailto:edk2-devel@lists.sourceforge.net> >>> https://lists.sourceforge.net/lists/listinfo/edk2-devel >>> <https://lists.sourceforge.net/lists/listinfo/edk2-devel> >>> >>> ------------------------------------------------------------------------------ >>> _______________________________________________ >>> edk2-devel mailing list >>> edk2-devel@lists.sourceforge.net <mailto:edk2-devel@lists.sourceforge.net> >>> https://lists.sourceforge.net/lists/listinfo/edk2-devel >>> <https://lists.sourceforge.net/lists/listinfo/edk2-devel> >>> >>> ------------------------------------------------------------------------------ >>> _______________________________________________ >>> edk2-devel mailing list >>> edk2-devel@lists.sourceforge.net <mailto:edk2-devel@lists.sourceforge.net> >>> https://lists.sourceforge.net/lists/listinfo/edk2-devel >>> <https://lists.sourceforge.net/lists/listinfo/edk2-devel> >> ------------------------------------------------------------------------------ >> _______________________________________________ >> edk2-devel mailing list >> edk2-devel@lists.sourceforge.net <mailto:edk2-devel@lists.sourceforge.net> >> https://lists.sourceforge.net/lists/listinfo/edk2-devel > > ------------------------------------------------------------------------------ > _______________________________________________ > edk2-devel mailing list > edk2-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/edk2-devel
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