jhell wrote: > On Sun, 21 Mar 2010 20:54, jhell@ wrote: >> I played with it on one re-compile of a kernel and for the sake of it >> DFLTPHYS=128 MAXPHYS=256 and found out that I could not cause a crash >> dump to be performed upon request (reboot -d) due to the boundary >> being hit for DMA which is 65536. Obviously this would have to be >> adjusted in ata-dma.c. >> >> I suppose that there would have to be a better way to get the real >> allowable boundary from the running system instead of setting it >> statically. >> >> Other then the above I do not see a reason why not... It is HEAD and >> this is the type of experimental stuff it was meant for. > > I should have also said that I also repeated the above without setting > DFLTPHYS and setting MAXPHYS to 256.
It was bad idea to increase DFLTPHYS. It is not intended to be increased. About DMA boundary, I do not very understand the problem. Yes, legacy ATA has DMA boundary of 64K, but there is no problem to submit S/G list of several segments. How long ago have you tried it, on which controller and which diagnostics do you have? -- 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"
