On Wed, Sep 17, 2003 at 06:12:44PM -0400, Andrew Gallatin wrote: >My question is: What the heck could the SMP kernel be doing which >causes the DMA to "complete" faster?
My guess is that this is a coherency issue rather than a timing issue. The SMP kernels are far more careful about ensuring consistency between CPUs and this could be fixing/masking the problem That said, any decent disk controller uses DMA and if the UP kernel really did have PCI-bus coherency problems (or massive delays), a significant part of the user-base would be screaming. The other possibility: Is your PCI card doing something wierd? Are you bending one of the PCI specs a bit far? Peter _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
