Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753176AbaFMIny (ORCPT ); Fri, 13 Jun 2014 04:43:54 -0400 Received: from mail-la0-f49.google.com ([209.85.215.49]:43804 "EHLO mail-la0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750852AbaFMInu (ORCPT ); Fri, 13 Jun 2014 04:43:50 -0400 MIME-Version: 1.0 In-Reply-To: References: Date: Fri, 13 Jun 2014 10:43:47 +0200 X-Google-Sender-Auth: Npb1rtJ7yrjjhKwYRbHVkDMEQ70 Message-ID: Subject: Re: [-next] Regression: ssh log in slowdown From: Geert Uytterhoeven To: Tom Herbert Cc: "David S. Miller" , Linux-Next , Linux-sh list , "linux-kernel@vger.kernel.org" , "netdev@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Tom, On Fri, Jun 13, 2014 at 10:21 AM, Tom Herbert wrote: >> I assume this is the series "[PATCH 0/4] Checksum fixes" >> (marc.info/?l=linux-netdev&m=140261417832399&w=2)? >> > Yes. > >> As I'm not subscribed to netdev, I cannot reply to that thread. >> >> "[PATCH 1/4] net: Fix save software checksum complete" fixes the issue >> for me. >> However, "[PATCH 2/4] udp: call __skb_checksum_complete when doing full >> checksum" reintroduces the exact same bad behavior :-( >> > This implies the problem is happening in UDP path. AFAICT skb->csum is > correct, and I don't seem to be able to reproduce the issue on my setup. > It is possible that an skb copy is happening in which case we don't copy > csum_valid so that checksum_unnecessary would fail in this case. > > Can you try with the patch below. Thanks! > > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > index bf92824..9cd5344 100644 > --- a/net/core/skbuff.c > +++ b/net/core/skbuff.c > @@ -689,6 +689,9 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old) > new->ooo_okay = old->ooo_okay; > new->no_fcs = old->no_fcs; > new->encapsulation = old->encapsulation; > + new->encap_hdr_csum = old->encap_hdr_csum; > + new->csum_valid = old->csum_valid; > + new->csum_complete_sw = old->csum_complete_sw; > #ifdef CONFIG_XFRM > new->sp = secpath_get(old->sp); > #endif Thanks, I applied the series "[PATCH 0/4] Checksum fixes", and the fix above, but it doesn't help. Note that I'm also using NFS root, which doesn't seem to be affected. I can happily run "ls -R /" on the serial console during the 10 s delay in ssh. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/