Messages in this thread | | | Date | Thu, 15 Jul 2021 14:49:08 +0300 | From | Vladimir Oltean <> | Subject | Re: [PATCH 2/2] net: dsa: tag_ksz: dont let the hardware process the layer 4 checksum |
| |
On Thu, Jul 15, 2021 at 01:16:12PM +0200, Lino Sanfilippo wrote: > Sure, I will test this solution. But I think NETIF_F_FRAGLIST should also be > cleared in this case, right?
Hmm, interesting question. I think only hns3 makes meaningful use of NETIF_F_FRAGLIST, right? I'm looking at hns3_fill_skb_to_desc(). Other drivers seem to set it for ridiculous reasons - looking at commit 66aa0678efc2 ("ibmveth: Support to enable LSO/CSO for Trunk VEA.") - they set NETIF_F_FRAGLIST and then linearize the skb chain anyway. The claimed 4x throughput benefit probably has to do with less skbs traversing the stack? I don't know.
Anyway, it is hard to imagine all the things that could go wrong with chains of IP fragments on a DSA interface, precisely because I have so few examples to look at. I would say, header taggers are probably fine, tail taggers not so much, so apply the same treatment as for NETIF_F_SG?
| |