Julian Elischer wrote: > In the Fusion-io driver we find that the limiting factor is not the > size of MAXPHYS, but the fact that we can not push more than > 170k tps through geom. (in my test machine. I've seen more on some > beefier machines), but that is only a limit on small transacrtions, > or in the case of large transfers the DMA engine tops out before a > bigger MAXPHYS would make any difference.
Yes, GEOM is quite CPU-hungry on high request rates due to number of context switches. But impact probably may be reduced from two sides: by reducing overhead per request, or by reducing number of requests. Both ways may give benefits. If common opinion is not to touch defaults now - OK, agreed. (Note, Scott, I have agreed :)) But returning to the original question, does somebody knows real situation when increased MAXPHYS still causes problems? At least to make it safe. -- Alexander Motin _______________________________________________ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"