July 21, 2011
6:23 p.m.
On Thu, Jul 21, 2011 at 11:48 PM, mindentropy <mindentropy@gmail.com> wrote:
Sorry to kicks in... Was wondering where you were :)
hm, quite likely you run out of contigous virtual address space that as big as you requested... in above, you requested 16 MiB, right?
Not virtual address space but physical page frames. Yes I requested 16MB. I want a huge chunk for dma for a high bandwidth pcie(16GB/s!) device . I am thinking in terms of no scatter gather but generally any sane device would have one.
do you see any performance implication of scatter-gather? I think unless you reach limits, performance should not vary much. Just curious to know what sort of device it is targeting 16GB/s?