Messages in this thread | | | From | Bhavana Nagendra <> | Subject | RE: Alloc and lock down large amounts of memory | Date | Tue, 20 Aug 2002 15:08:23 -0500 |
| |
> > Curiosity: why do you want to do device DMA buffer > allocation from userland?
I need 256M memory for a graphics operation. It's a requiremment, can't change it. There will be other reasonably sized allocs in kernel space, this is a special case that will be done from userland. As discussed earlier in this thread, there's no good way of alloc()ing and pinning that much in DMA memory space, is there?
Gilad, I looked at mm/memory.c and map_user_kiobuf() lets me map user memory into kernel memory and pins it down. A scatter gatter mapping (say, pci_map_sg()) will create a seemingly contiguous buffer for DMA purposes. Does that sound right to you?
Bhavana - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |