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| author | Alexander Lobakin <alexandr.lobakin@intel.com> | 2021-12-08 15:06:59 +0100 |
|---|---|---|
| committer | Tony Nguyen <anthony.l.nguyen@intel.com> | 2022-01-31 09:47:13 -0800 |
| commit | f9e61d365bafdee40fe2586fc6be490c3e824dad (patch) | |
| tree | eecd18eb905b1042156477113e0096cdf2b49fed /drivers/net/ethernet/intel/igc/igc_main.c | |
| parent | 45a34ca68070e34e09d5bf4309f7f1f286a27fc7 (diff) | |
| download | lwn-f9e61d365bafdee40fe2586fc6be490c3e824dad.tar.gz lwn-f9e61d365bafdee40fe2586fc6be490c3e824dad.zip | |
igc: don't reserve excessive XDP_PACKET_HEADROOM on XSK Rx to skb
{__,}napi_alloc_skb() allocates and reserves additional NET_SKB_PAD
+ NET_IP_ALIGN for any skb.
OTOH, igc_construct_skb_zc() currently allocates and reserves
additional `xdp->data_meta - xdp->data_hard_start`, which is about
XDP_PACKET_HEADROOM for XSK frames.
There's no need for that at all as the frame is post-XDP and will
go only to the networking stack core.
Pass the size of the actual data only (+ meta) to
__napi_alloc_skb() and don't reserve anything. This will give
enough headroom for stack processing.
Also, net_prefetch() xdp->data_meta and align the copy size to
speed-up memcpy() a little and better match igc_construct_skb().
Fixes: fc9df2a0b520 ("igc: Enable RX via AF_XDP zero-copy")
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Tested-by: Nechama Kraus <nechamax.kraus@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Diffstat (limited to 'drivers/net/ethernet/intel/igc/igc_main.c')
| -rw-r--r-- | drivers/net/ethernet/intel/igc/igc_main.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index 6b51baadee3d..b965fb809d84 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -2446,19 +2446,20 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget) static struct sk_buff *igc_construct_skb_zc(struct igc_ring *ring, struct xdp_buff *xdp) { + unsigned int totalsize = xdp->data_end - xdp->data_meta; unsigned int metasize = xdp->data - xdp->data_meta; - unsigned int datasize = xdp->data_end - xdp->data; - unsigned int totalsize = metasize + datasize; struct sk_buff *skb; - skb = __napi_alloc_skb(&ring->q_vector->napi, - xdp->data_end - xdp->data_hard_start, + net_prefetch(xdp->data_meta); + + skb = __napi_alloc_skb(&ring->q_vector->napi, totalsize, GFP_ATOMIC | __GFP_NOWARN); if (unlikely(!skb)) return NULL; - skb_reserve(skb, xdp->data_meta - xdp->data_hard_start); - memcpy(__skb_put(skb, totalsize), xdp->data_meta, totalsize); + memcpy(__skb_put(skb, totalsize), xdp->data_meta, + ALIGN(totalsize, sizeof(long))); + if (metasize) { skb_metadata_set(skb, metasize); __skb_pull(skb, metasize); |