on 10/12/2010 16:48 Andriy Gapon said the following: > But maybe I misunderstood your question and you talked about a different I/O > layer > or different I/O path. >
Oh, probably you talk about physread/physwrite == physio. Indeed, it issues bio-s with max size of si_iosize_max and runs them sequentially. Besides, if uio is really "vectored", then each uio sub-buffer is processed sequentially too. This is probably less fast than running the requests in parallel; plus side could be that less KVA is required for mapping user space buffer (UIO_USERSPACE case) into kernel. Not sure if the latter is much of concern though. The sequential code is simpler too :-) -- Andriy Gapon _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[email protected]"
