Hello, We made some testing on out cpu, installed with 4.1.15-rt17 kernel, and we observed significant difference in latency between posic to non-posix cyclictest benchmark. with non posix we reach max ~50usec while with posix we reach max ~170usec On checking the exaples in cyclic test wiki, it seems that the difference should not be that big : https://rt.wiki.kernel.org/index.php/Cyclictest What is the reason for such difference in behaviour ? Does it mean we better use non-posix timer in application ? kernel version ========== user@user-desktop:~/rt-tests-1.0$ uname -a Linux user-desktop 4.1.15-rt17mah #6 SMP PREEMPT RT Wed Dec 23 20:12:08 CET 2015 x86_64 x86_64 x86_64 GNU/Linux cpu information ========== user@user-desktop:~/rt-tests-1.0$ cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 55 model name : Intel(R) Atom(TM) CPU E3815 @ 1.46GHz stepping : 9 microcode : 0x903 cpu MHz : 1463.000 cache size : 512 KB physical id : 0 siblings : 1 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 11 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm sse4_1 sse4_2 movbe popcnt tsc_deadline_timer aes rdrand lahf_lm 3dnowprefetch arat epb dtherm tpr_shadow vnmi flexpriority ept vpid tsc_adjust smep erms bugs : bogomips : 2930.40 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: Best Regards, Ran -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
