Dear Corinna,
Thank you for the patch. Am 23.04.24 um 12:24 schrieb Corinna Vinschen:
From: Paolo Abeni <[email protected]>
It’d be great if you removed the trailing dot/period in the commit message summary.
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.
If you have a reproducer for this, it’d be great if you could document it in the commit message.
Fixes: 3948b05950fd ("net: introduce a config option to tweak MAX_SKB_FRAG") Reported-by: Jan Tluka <[email protected]> Reported-by: Jirka Hladky <[email protected]> Reported-by: Sabrina Dubroca <[email protected]> Tested-by: Sabrina Dubroca <[email protected]> Tested-by: Corinna Vinschen <[email protected]> Signed-off-by: Paolo Abeni <[email protected]> --- 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
Kind regards, Paul
