Le 03/09/2010 15:38, George Bosilca a écrit : > Jeff, > > I think you will have to revert this patch as the btl_bandwidth __IS__ > supposed to be in Mbs and not MBs. We usually talk about networks in Mbs > (there is a pattern in Ethernet 1G/10G, Myricom 10G). In addition the > original design of the multi-rail was based on this assumption, and the > multi-rail handling code deal with these values (at that level I don't think > it really matters, but at least it needs consistent values from all BTLs). > > However, going over the existing BTLs I can see that some BTLs do not > correctly set this value: > > BTL Bandwidth Auto-detect Status > Elan 2000 NO Correct >
2000 looks strange to me. Last time I played with Elan4, bandwidth was 900MB/s or so. > GM 250 NO Doubtful > MX 2000/10000 YES (Mbs) Correct (before the patch) > OFUD 800 NO Doubtful > OpenIB 2000/4000/8000 YES (Mbs) Correct (multiplied by the > active_width) > I found the problem when using both MX and OpenIB at the same time, so they can't be both wrong or both correct. IB was reporting 800, not 2000/4000/8000. Maybe because auto-detect didn't work and the default is wrong: btl_openib_mca.c:527: mca_btl_openib_module.super.btl_bandwidth = 800; Brice
