In investigating random glitches to the kernel logfile, apparently originating from 'rtapi_print_msg' I dug in and got my hands dirty.
The reason for my investigation was text like this in '/var/log/messages' --- May 21 18:46:12 sixis kernel: hm2/hm2_5i23.0: IO Pin 037 (P3-27): Encoder #7, pin A (Input) May 21 18:46:12 sixis kernel: hm2/hm2_5hm2/hm2_5i23.0: IO Pin 039 (P3-31): Encoder #6, pin A (Input) May 21 18:46:12 sixis kernel: hm2/hm2_5i23.0: IO Pin 040 (P3-33): Encoder #7, pin Ind --- Where the enumeration of 'IO Pin 38' is clobbered :-/ Because the location of the clobbered pin was somewhat random, and because this effect did not occur when booting from the stable ISO, I suspected a race in the interaction with the kernel's logging facility. Therefore I thought I'd try a new kernel. Currently I am using 2.6.38.8 patched with RTAI 3.9magma from August2012. This is a 64 bit kernel. What I found out about RTAI and Xenomai? Xenomai 2.6.2.1 stable or GIT do not handle SMI masking correctly for my ICH7 chipsets. In the case of the stable download the chipset is detected but the SMI workaround fails to apply. --- May 25 07:42:05 sixis kernel: Xenomai: real-time nucleus v2.6.2.1 (Day At The Beach) loaded. May 25 07:42:05 sixis kernel: Xenomai: debug mode enabled. May 25 07:42:05 sixis kernel: Xenomai: SMI-enabled chipset found May 25 07:42:05 sixis kernel: Xenomai: SMI workaround failed! --- In the case of the GIT version the kernel command line parameter 'xeno_hal.smi=1' is not respected. --- May 26 08:31:48 sixis kernel: Xenomai: real-time nucleus v2.6.2.1 (Day At The Beach) loaded. May 26 08:31:48 sixis kernel: Xenomai: debug mode enabled. May 26 08:31:48 sixis kernel: Xenomai: SMI-enabled chipset found, but SMI workaround disabled May 26 08:31:48 sixis kernel: (see xeno_hal.smi parameter). You may encounter May 26 08:31:48 sixis kernel: high interrupt latencies! --- I was seeing latency as high as 100us with Xenomai, so it is currently not working for me. The RTAI userspace 3.9.1magma(25may checkout) does not compile for x86_64, although kernel 3.5.7 patches and compiles cleanly. So I remain with last years 2.6.38 kernel. Thats sort of OK, I guess. This kernel give me <5us latency on a Pentium-D system. Has anybody got a 3.x 64 bit realtime kernel working? Which one on what chipset and how? On the the problem of understanding the glitches in the kernel log. I am tending to thing that my test system is too fast, and is overwriting the buffer of the 'rtapi_print_msg' function? I tried turning on the debugging switches of hostmot2, as described in the manpage 'loadrt hostmot2 debug_pin_descriptors=1'. To no effect. I suppose I will just re-compile the hostmot2 stuff with the debugging hardcoded in unless someone can recommend how to switch it on from withing halrun. Finally, is anybody else running linuxCNC on 64 bit systems? I am beginning to doubt that the codebase is 64bit clean. Thanks jCandlish . ------------------------------------------------------------------------------ Try New Relic Now & We'll Send You this Cool Shirt New Relic is the only SaaS-based application performance monitoring service that delivers powerful full stack analytics. Optimize and monitor your browser, app, & servers with just a few lines of code. Try New Relic and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_may _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
