On 2/21/22 8:31 PM, Dongli Zhang wrote: > Hi David, > > On 2/21/22 7:24 PM, David Ahern wrote: >> On 2/20/22 10:34 PM, Dongli Zhang wrote: >>> The TAP can be used as vhost-net backend. E.g., the tap_handle_frame() is >>> the interface to forward the skb from TAP to vhost-net/virtio-net. >>> >>> However, there are many "goto drop" in the TAP driver. Therefore, the >>> kfree_skb_reason() is involved at each "goto drop" to help userspace >>> ftrace/ebpf to track the reason for the loss of packets. >>> >>> The below reasons are introduced: >>> >>> - SKB_DROP_REASON_SKB_CSUM >>> - SKB_DROP_REASON_SKB_COPY_DATA >>> - SKB_DROP_REASON_SKB_GSO_SEG >>> - SKB_DROP_REASON_DEV_HDR >>> - SKB_DROP_REASON_FULL_RING >>> >>> Cc: Joao Martins <joao.m.martins@xxxxxxxxxx> >>> Cc: Joe Jin <joe.jin@xxxxxxxxxx> >>> Signed-off-by: Dongli Zhang <dongli.zhang@xxxxxxxxxx> >>> --- >>> Changed since v1: >>> - revise the reason name >>> Changed since v2: >>> - declare drop_reason as type "enum skb_drop_reason" >>> - handle the drop in skb_list_walk_safe() case >>> >>> drivers/net/tap.c | 35 +++++++++++++++++++++++++---------- >>> include/linux/skbuff.h | 9 +++++++++ >>> include/trace/events/skb.h | 5 +++++ >>> 3 files changed, 39 insertions(+), 10 deletions(-) >>> >> >> couple of places where the new reason should be in reverse xmas order; >> logic wise: >> >> Reviewed-by: David Ahern <dsahern@xxxxxxxxxx> >> > > I will re-order the reasons in the same patch and re-send with your Reviewed-by > in the next version. > I have sent out v4 and I finally decide to not re-order reasons for this patch as this may makes trouble for backport. I will not follow the reverse xmas order here, as all existing variables are not declared in reverse xmas order. Thank you very much! Dongli Zhang
