Tue, Apr 23, 2024 at 12:24:46PM CEST, vinsc...@redhat.com wrote:
>From: Paolo Abeni <pab...@redhat.com>
>
>Sabrina reports that the igb driver does not cope well with large
>MAX_SKB_FRAG values: setting MAX_SKB_FRAG to 45 causes payload
>corruption on TX.
>
>The root cause of the issue is that the driver does not take into
>account properly the (possibly large) shared info size when selecting
>the ring layout, and will try to fit two packets inside the same 4K
>page even when the 1st fraglist will trump over the 2nd head.
>
>Address the issue forcing the driver to fit a single packet per page,
>leaving there enough room to store the (currently) largest possible
>skb_shared_info.
>
>Fixes: 3948b05950fd ("net: introduce a config option to tweak MAX_SKB_FRAG")
>Reported-by: Jan Tluka <jtl...@redhat.com>
>Reported-by: Jirka Hladky <jhla...@redhat.com>
>Reported-by: Sabrina Dubroca <s...@queasysnail.net>
>Tested-by: Sabrina Dubroca <s...@queasysnail.net>
>Tested-by: Corinna Vinschen <vinsc...@redhat.com>
>Signed-off-by: Paolo Abeni <pab...@redhat.com>Reviewed-by: Jiri Pirko <j...@nvidia.com> Next time, please indicate target tree (net) in [patch] brackets. >--- > drivers/net/ethernet/intel/igb/igb_main.c | 1 + > 1 file changed, 1 insertion(+) > >diff --git a/drivers/net/ethernet/intel/igb/igb_main.c >b/drivers/net/ethernet/intel/igb/igb_main.c >index a3f100769e39..22fb2c322bca 100644 >--- a/drivers/net/ethernet/intel/igb/igb_main.c >+++ b/drivers/net/ethernet/intel/igb/igb_main.c >@@ -4833,6 +4833,7 @@ static void igb_set_rx_buffer_len(struct igb_adapter >*adapter, > > #if (PAGE_SIZE < 8192) > if (adapter->max_frame_size > IGB_MAX_FRAME_BUILD_SKB || >+ SKB_HEAD_ALIGN(adapter->max_frame_size) > (PAGE_SIZE / 2) || > rd32(E1000_RCTL) & E1000_RCTL_SBP) > set_ring_uses_large_buffer(rx_ring); > #endif >-- >2.44.0 > >
