On Mon, 2010-03-22 at 22:13 +0800, Stanislaw Gruszka wrote: > > Changing default options in upstream kernel is problematic. Since > 2.6.33 we have different memory allocations to avoid failures due to > buddy allocator fragmentation. It is optimized for normal usage case, > but with swcrypto when and skb's have to be linearized memory usage by > driver increase about 2 times. Have you benchmarked about this change? Before paged Rx skb is used, we have to allocate (8K + sizeof(struct skb_shared_info)) linear skb, which is an order-2 allocation. Now with paged skb, first we do an order-1 allocation to hold the packet from device, then skb_linearize (if swcrypto is used) the skb. Note, in most of the time, the skb->len will be far less than 8K (unless 11n aggregation is used). So normally skb_linearize only does an order-1 (or even order-0) allocation in most. So in the swcrypto case, the paged Rx patch changes the memory allocation from one order-2 into two separated order-1 allocations. It should still be an improvement. No? Thanks, -yi _______________________________________________ kernel mailing list kernel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/kernel
