From: Doron Roberts-Kedes <doro...@fb.com> Date: Tue, 28 Aug 2018 16:33:57 -0700
> decrypt_skb fails if the number of sg elements required to map it > is greater than MAX_SKB_FRAGS. nsg must always be calculated, but > skb_cow_data adds unnecessary memcpy's for the zerocopy case. > > The new function skb_nsg calculates the number of scatterlist elements > required to map the skb without the extra overhead of skb_cow_data. > This patch reduces memcpy by 50% on my encrypted NBD benchmarks. > > Reported-by: Vakul Garg <vakul.g...@nxp.com> > Reviewed-by: Vakul Garg <vakul.g...@nxp.com> > Tested-by: Vakul Garg <vakul.g...@nxp.com> > Signed-off-by: Doron Roberts-Kedes <doro...@fb.com> Applied, thank you.
