Messages in this thread | | | Date | Fri, 12 Feb 1999 18:05:06 -0800 (PST) | From | Simon Kirby <> | Subject | Re: SCSI tape buffer allocation hitting memory allocation |
| |
On Fri, 12 Feb 1999, Simon Kirby wrote:
> Hmm...it makes obvious sense that some sort of transfer from a device to > physical memory wouldn't be able to go through the page translation on the > CPU unless the CPU was doing the transfer, so it makes sense that > vmalloc()ed pages wouldn't work. I wonder what the floppy driver does, > then...
Okay, now that I've realized my first idea is really dumb, I'd like to confirm that DMA to an onboard/PCI device does actually work addressing physical memory > 64MB. Is this true? I changed scsi_init_malloc() to remove the GFP_DMA flag iff the first allocation w/GFP_DMA fails...it seems to now work (but obviously it will blow up for ISA cards). Is GFP_DMA is used anywhere else other than to tell __get_free_pages() to only allocate in areas < 64MB)? I'm assuming this should be safe (for the case of this one machine w/no ISA SCSI controllers) if not.
Simon-
| Simon Kirby | Systems Administration | | mailto:sim@netnation.com | NetNation Communications | | http://www.netnation.com/ | Tech: (604) 684-6892 |
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |