Hi, i`m working on the embedded hypervisor targeting QorIQ platforms (p3041/p4080). I have working prototype starting custom RTOS on just single core in the guest space. What I see is the big latency (up to 3 times more) in RTOS running atop of HV comparing to RTOS running bare-metal. I`m using lmbench utility. It shows
nteger mul: 3.48 nanoseconds integer div: 30.44 nanoseconds integer mod: 13.92 nanoseconds int64 bit: 1.75 nanoseconds int64 add: 1.42 nanoseconds int64 mul: 6.95 nanoseconds HV:hvpriv_count 60000 int64 div: 447.56 nanoseconds int64 mod: 385.42 nanoseconds float add: 7.12 nanoseconds float mul: 6.95 nanoseconds float div: 33.05 nanoseconds double add: 7.11 nanoseconds double mul: 8.70 nanoseconds double div: 57.36 nanoseconds float bogomflops: 46.98 nanoseconds double bogomflops: 73.09 nanoseconds The bare-metal results are 3x better. Does anybody have any ideas on what may be the source of such latency ? I forward all the exceptions to the guest w/o affecting HV. Only hvpriv is processed, it takes not more than 2 bus cycles. Sorry for poor english _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
