cioli@savax.UUCP (Jeff J. Cioli) (11/22/89)
Does anyone have any performance data (e.g. benchmarks results, papers) con- cerning context switch, interrupt latency, message delivery latency, etc for VxWorks and the various underlying kernels ? Thanks
wbrown@beva.bev.lbl.gov (Bill Brown) (11/27/89)
In article <1081@savax.UUCP> cioli@savax.UUCP (Jeff J. Cioli) writes: >Does anyone have any performance data (e.g. benchmarks results, papers) con- >cerning context switch, interrupt latency, message delivery latency, etc for >VxWorks and the various underlying kernels ? > >Thanks ____ | |____| | | | | Time Between Writes Square wave Frequency MVME-147 Square-wave Direct write* 2 uS. 250 KHz. Function Call* 5 uS 100 KHz MVME-133 {CMC E-net, MVME-025 VME Controller} Square-wave Direct Write* 3 uS. 167 KHz. Function Call* 8.5 uS. 118 Khz. RPC xx Ms. xx Hz. * Output device is ACROMAG 9210 D.A.C. board I also made a couple of interrupt-latency checks - as best I can recall it's about 15 microseconds between the interrupt on the VME bus and the first instruction in the interrupt function. This was probably using a '147 board (naw - I don't gotta write it down - I can remember it when I need it). We are using the Wind kernel. I believe that a task switch takes on the order of couple of hundred microseconds but don't have any hard figures. It would be possible to cut down the interrupt latency a little bit by doing some assembly language stuff, rather than using vxWorks' intConnect() but the gain is not much, a say less than a factor of 2. I hope this helps - it's not everything you asked for, but at least it's something. -bill wlbrown@lbl.gov Disclaimer: These opinions are my own and have nothing to do with the official policy or management of L.B.L, who probably couldn't care less about employees who play with trains.
sccowan@watmsg.waterloo.edu (S. Crispin Cowan) (11/29/89)
In article <4295@helios.ee.lbl.gov> wbrown@beva.bev.lbl.gov (Bill Brown) writes: >In article <1081@savax.UUCP> cioli@savax.UUCP (Jeff J. Cioli) writes: >>Does anyone have any performance data (e.g. benchmarks results, papers) con- >>cerning context switch, interrupt latency, message delivery latency, etc for >>VxWorks and the various underlying kernels ? >> >>Thanks >MVME-133 {CMC E-net, MVME-025 VME Controller} > Square-wave > > Direct Write* 3 uS. > 167 KHz. > RPC xx Ms. > xx Hz. I would really like to see the RPC figure, if anyone has it. Also, any of the context-switching figures mentioned in the first message would be appreciated. > -bill > wlbrown@lbl.gov ---------------------------------------------------------------------- Login name: sccowan In real life: S. Crispin Cowan Office: DC3548 x3934 Home phone: 570-2517 Post Awful: 60 Overlea Drive, Kitchener, N2M 1T1 UUCP: watmath!watmsg!sccowan Domain: sccowan@watmsg.waterloo.edu "We have to keep pushing the pendulum so that it doesn't get stuck in the extremes--only the middle is worth having." Orwell, Videobanned -- Kim Kofmel