Thanks Andrew, let me try with this library and see how this works out. FYI: Elapsed time/Duration is calculated as follows: (End time-Start time) /frequency. End time & start time is calculated from the performance counter and the frequency is obtained from the counter properties call.
Sai From: Andrew Fish [mailto:af...@apple.com] Sent: Friday, June 05, 2015 4:34 PM To: edk2-devel@lists.sourceforge.net Subject: Re: [edk2] getsystemtime-- help On Jun 5, 2015, at 4:29 PM, Andrew Fish <af...@apple.com<mailto: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] 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 Which a lot of times is built on: 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] 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] 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 ------------------------------------------------------------------------------ _______________________________________________ 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<mailto:edk2-devel@lists.sourceforge.net> 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<mailto:edk2-devel@lists.sourceforge.net> 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
