In an attempt to avoid having to allocate memory on the send path, the netvsc driver was requesting additional head room so that both rndis header and the netvsc packet (the state that had to persist) could be placed in the skb. Since the amount of head room requested was exceeding the default head room as set in LL_MAX_HEADER, we were forcing a reallocation of skb. With this patch-set, I have reduced the size of the netvsc packet to 40 bytes and with this reduction we don't need to ask for any additional headroom. We place the rndis header in the skb head room and we place the netvsc packet in control buffer area in the skb. K. Y. Srinivasan (8): hv_netvsc: Resize some of the variables in hv_netvsc_packet hv_netvsc: Rearrange the hv_negtvsc_packet to be space efficient hv_netvsc: Eliminate the channel field in hv_netvsc_packet structure hv_netvsc: Eliminate rndis_msg pointer from hv_netvsc_packet structure hv_netvsc: Eliminatte the data field from struct hv_netvsc_packet hv_netvsc: Eliminate send_completion from struct hv_netvsc_packet hv_netvsc: Eliminate send_completion_ctx from struct hv_netvsc_packet hv_netvsc: Don't ask for additional head room in the skb Vitaly Kuznetsov (2): hv_netvsc: move subchannel existence check to netvsc_select_queue() hv_netvsc: remove locking in netvsc_send() drivers/net/hyperv/hyperv_net.h | 48 +++++++++++++++++------------------- drivers/net/hyperv/netvsc.c | 42 ++++++++++++-------------------- drivers/net/hyperv/netvsc_drv.c | 47 +++++++++++++++-------------------- drivers/net/hyperv/rndis_filter.c | 21 ++++++++++------ 4 files changed, 72 insertions(+), 86 deletions(-) -- 1.7.4.1 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel