Version : 1.0.0a Author : Jason Vas Dias Provides :
- Detection of CPU & linux synthesized TSC CPU capabilities: constant_tsc nonstop_tsc rdtsc tsc_adjust CPUID:15H{ ART / TSC ratio, ART FREQ }
- Usage of Linux VDSO resident (shared memory map with kernel) vsyscall_gtod_data structure to duplicate exactly how Linux interprets TSC, but in User-Space ; also functions to read the actual 'Calibrated' TSC frequency value from live kernel.
- Installed files:
/usr/lib64/libIA64_TSC_LNX.so -> libIA64_TSC_LNX.so.${IA64_TSC_LNX_VERSION} /usr/include/IA64_TSC_LNX/IA64_TSC.h /usr/share/man/man3/IA64_TSC.3 ( if pkgconfig installed ): /usr/lib/pkgconfig/IA64_TSC.pc /usr/bin/tsc_info : A bash shell script to emit information about TSC. - Functions:
bool IA64_has_monotonic_nonstop_tsc() ; // IFF the above function returns true, then these functions return // the Time Stamp Counter value: U64_t IA64_rdtscp(); /* cancellation point */ U64_t IA64_rdtsc(); /* not cancellation point : do not use outside assembler * where you control processor pipelining & speculative * branch prediction */
Demonstration :
$ make $ ./ttsc1 max_extended_leaf: 80000008 has tsc: 1 constant: 1 Invariant TSC is enabled: Actual TSC freq: 2.893299GHz - TSC adjust: 1. ts2 - ts1: 219 ts3 - ts2: 107 ns1: 0.000000334 ns2: 0.000001955 ts3 - ts2: 132 ns1: 0.000000329 ts3 - ts2: 15 ns1: 0.000000323 ts3 - ts2: 17 ns1: 0.000000372 ts3 - ts2: 17 ns1: 0.000000319 ts3 - ts2: 17 ns1: 0.000000351 ts3 - ts2: 17 ns1: 0.000000342 ts3 - ts2: 17 ns1: 0.000000350 ts3 - ts2: 17 ns1: 0.000000358 ts3 - ts2: 17 ns1: 0.000000347 ts3 - ts2: 17 ns1: 0.000000319 t1 - t0: 46223 - ns2: 0.000047863
The numbers on the right (shown as ns1) are the delta of the results clock_gettime(CLOCK_MONOTONIC_RAW(), &tsp), those on the left (shown as 'ts3 - ts2') are the delta of the results of IA64_s_ns_since_start() which uses IA64_rdtscp() .
READERS PLEASE NOTE :
THIS PACKAGE IS NOT YET READY . I am creating the GIT today (2017-04-15) which is my first GitHub project , to see what facilities GitHub provides & plan how to structure build & repository .
This message will disappear in a few days when the project should be considered 'Ready For Download'.
I would make this GIT private during this period, but I don't want to pay a monthly fee for this.