ixgbe: Add support for maximum headroom when using build_skb
This patch increases the headroom allocated when using build_skb on a system with 4K pages. Specifically the breakdown of headroom versus cache size is as follows: L1 Cache Size Headroom 64 192 64, NET_IP_ALIGN == 2 194 128 128 128, NET_IP_ALIGN == 2 130 256 512 256, NET_IP_ALIGN == 2 258 I stopped at supporting only a cache line size of 256 as that was the largest cache size I could find supported in the kernel. With this we are guaranteeing at least 128 bytes of headroom to spare in the frame. This should be enough for us to insert a couple of IPv6 headers if needed which is likely enough room for anything XDP should need. I'm leaving the padding for systems with pages larger than 4K unmodified for now. XDP currently isn't really setup to work on those types of systems so we can cross that bridge when we get there. Signed-off-by:Alexander Duyck <alexander.h.duyck@intel.com> Tested-by:
Andrew Bowers <andrewx.bowers@intel.com> Signed-off-by:
Jeff Kirsher <jeffrey.t.kirsher@intel.com>
parent
f4a6374b
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