From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Dave Young" Subject: Re: 2.6.24-rc8-mm1 : net tcp_input.c warnings Date: Fri, 25 Jan 2008 09:30:42 +0800 Message-ID: References: <20080122.190137.206066966.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "Kamalesh Babulal" , "Krishna Kumar2" , "Denys Fedoryshchenko" , "David Miller" , LKML , Netdev , "Andrew Morton" To: "=?ISO-8859-1?Q?Ilpo_J=E4rvinen?=" Return-path: Received: from nz-out-0506.google.com ([64.233.162.233]:56524 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751875AbYAYBaq convert rfc822-to-8bit (ORCPT ); Thu, 24 Jan 2008 20:30:46 -0500 Received: by nz-out-0506.google.com with SMTP id s18so368985nze.1 for ; Thu, 24 Jan 2008 17:30:43 -0800 (PST) In-Reply-To: Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: On Jan 24, 2008 5:54 PM, Ilpo J=E4rvinen wr= ote: > On Thu, 24 Jan 2008, Dave Young wrote: > > Hi Dave (& others), > > > Thanks. > > Thanks a lot, I was first to ignore all these because they occurred > with newreno, but looked again... :-/ > > > New warning trigged with your debug patch: > > This was probably with the earlier one I sent to you because there's = still > this case remaining which itself is valid: > > > P: 5 L: 0 vs 0 S: 0 vs 1 w: 2044790889-2044796616 (0) > > ...snip... this is still ok state (S+L <=3D P): > > > > P: 5 L: 0 vs 0 S: 0 vs 3 w: 2044790889-2044796616 (0) > > TCP wq(s) < > > TCP wq(h) +++h+< > > l0 s3 f0 p5 seq: su2044790889 hs2044795029 sn2044796616 > > ------------[ cut here ]------------ > > WARNING: at net/ipv4/tcp_input.c:2169 tcp_mark_head_lost+0x122/0x15= 0() > > Modules linked in: snd_seq_dummy snd_seq_oss snd_seq_midi_event > > snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss eeprom e100 psmous= e > > snd_hda_intel snd_pcm snd_timer btusb bluetooth serio_raw snd 3c59x= sg > > evdev thermal soundcore rtc_cmos snd_page_alloc rtc_core rtc_lib > > i2c_i801 processor button intel_agp dcdbas pcspkr agpgart > > Pid: 0, comm: swapper Not tainted 2.6.24-rc8-mm1 #8 > > [] ? have_callable_console+0x20/0x30 > > [] warn_on_slowpath+0x54/0x80 > > [] ? tcp_print_queue+0x1a4/0x230 > > [] ? vprintk+0x308/0x320 > > [] ? vprintk+0x308/0x320 > > [] ? vprintk+0x308/0x320 > > [] ? tcp_verify_wq+0x116/0x1c0 > > [] tcp_mark_head_lost+0x122/0x150 > > [] tcp_update_scoreboard+0x4a/0x190 > > [] tcp_fastretrans_alert+0x4da/0x700 > > [] tcp_ack+0x1b3/0x3a0 > > [] tcp_rcv_established+0x3eb/0x710 > > [] tcp_v4_do_rcv+0xe5/0x100 > > [] tcp_v4_rcv+0x5db/0x660 > > [] ? tcp_v4_rcv+0x387/0x660 > > [] ? ip_local_deliver_finish+0x2d/0x1d0 > > [] ip_local_deliver_finish+0x84/0x1d0 > > [] ? ip_local_deliver_finish+0x2d/0x1d0 > > [] ? __lock_release+0x47/0x70 > > [] ip_local_deliver+0xb7/0xc0 > > [] ip_rcv_finish+0xb2/0x3c0 > > [] ? sock_def_readable+0x48/0xa0 > > [] ? sock_queue_rcv_skb+0xb1/0x1a0 > > [] ? sock_queue_rcv_skb+0xf7/0x1a0 > > [] ip_rcv+0x18f/0x290 > > [] ? packet_rcv_spkt+0xd0/0x130 > > [] netif_receive_skb+0x2b6/0x330 > > [] ? netif_receive_skb+0x127/0x330 > > [] ? process_backlog+0x83/0x100 > > [] process_backlog+0x8e/0x100 > > [] net_rx_action+0x13c/0x230 > > [] ? net_rx_action+0x59/0x230 > > [] __do_softirq+0x93/0x120 > > [] do_softirq+0x7a/0x80 > > [] irq_exit+0x65/0x90 > > [] do_IRQ+0x41/0x80 > > [] ? trace_hardirqs_on+0xb9/0x130 > > [] common_interrupt+0x2e/0x34 > > [] ? mwait_idle_with_hints+0x40/0x50 > > [] ? mwait_idle+0x0/0x20 > > [] mwait_idle+0x12/0x20 > > [] cpu_idle+0x61/0x110 > > [] rest_init+0x5d/0x60 > > [] start_kernel+0x1fa/0x260 > > [] ? unknown_bootoption+0x0/0x130 > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D > > ---[ end trace 14b601818e6903ac ]--- > > ------------[ cut here ]------------ > > WARNING: at net/ipv4/tcp_ipv4.c:197 tcp_verify_wq+0x1b6/0x1c0() > > Modules linked in: snd_seq_dummy snd_seq_oss snd_seq_midi_event > > snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss eeprom e100 psmous= e > > snd_hda_intel snd_pcm snd_timer btusb bluetooth serio_raw snd 3c59x= sg > > evdev thermal soundcore rtc_cmos snd_page_alloc rtc_core rtc_lib > > i2c_i801 processor button intel_agp dcdbas pcspkr agpgart > > Pid: 0, comm: swapper Not tainted 2.6.24-rc8-mm1 #8 > > [] ? have_callable_console+0x20/0x30 > > [] warn_on_slowpath+0x54/0x80 > > [] ? print_oops_end_marker+0x2a/0x30 > > [] ? warn_on_slowpath+0x59/0x80 > > [] ? tcp_print_queue+0x1a4/0x230 > > [] ? vprintk+0x308/0x320 > > [] ? vprintk+0x308/0x320 > > [] tcp_verify_wq+0x1b6/0x1c0 > > [] ? tcp_verify_wq+0x116/0x1c0 > > [] tcp_mark_head_lost+0xcc/0x150 > > [] tcp_update_scoreboard+0x4a/0x190 > > [] tcp_fastretrans_alert+0x4da/0x700 > > [] tcp_ack+0x1b3/0x3a0 > > [] tcp_rcv_established+0x3eb/0x710 > > [] tcp_v4_do_rcv+0xe5/0x100 > > [] tcp_v4_rcv+0x5db/0x660 > > [] ? tcp_v4_rcv+0x387/0x660 > > [] ? ip_local_deliver_finish+0x2d/0x1d0 > > [] ip_local_deliver_finish+0x84/0x1d0 > > [] ? ip_local_deliver_finish+0x2d/0x1d0 > > [] ? __lock_release+0x47/0x70 > > [] ip_local_deliver+0xb7/0xc0 > > [] ip_rcv_finish+0xb2/0x3c0 > > [] ? sock_def_readable+0x48/0xa0 > > [] ? sock_queue_rcv_skb+0xb1/0x1a0 > > [] ? sock_queue_rcv_skb+0xf7/0x1a0 > > [] ip_rcv+0x18f/0x290 > > [] ? packet_rcv_spkt+0xd0/0x130 > > [] netif_receive_skb+0x2b6/0x330 > > [] ? netif_receive_skb+0x127/0x330 > > [] ? process_backlog+0x83/0x100 > > [] process_backlog+0x8e/0x100 > > [] net_rx_action+0x13c/0x230 > > [] ? net_rx_action+0x59/0x230 > > [] __do_softirq+0x93/0x120 > > [] do_softirq+0x7a/0x80 > > [] irq_exit+0x65/0x90 > > [] do_IRQ+0x41/0x80 > > [] ? trace_hardirqs_on+0xb9/0x130 > > [] common_interrupt+0x2e/0x34 > > [] ? mwait_idle_with_hints+0x40/0x50 > > [] ? mwait_idle+0x0/0x20 > > [] mwait_idle+0x12/0x20 > > [] cpu_idle+0x61/0x110 > > [] rest_init+0x5d/0x60 > > [] start_kernel+0x1fa/0x260 > > [] ? unknown_bootoption+0x0/0x130 > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D > > ---[ end trace 14b601818e6903ac ]--- > > ...But this no longer is, and even more, L: 5 is not valid state at t= his > point all (should only happen if we went to RTO but it would reset S = to > zero with newreno): > > > P: 5 L: 5 vs 5 S: 0 vs 3 w: 2044790889-2044796616 (0) > > TCP wq(s) LLLLl< > > TCP wq(h) +++h+< > > l5 s3 f0 p5 seq: su2044790889 hs2044795029 sn2044796616 > > Surprisingly, it was the first time the WARN_ON for left_out returned > correct location. This also explains why the patch I sent to Krishna > didn't print anything (it didn't end up into printing because I forgo= t > to add L+S>P check into to the state checking if). > > ...so please, could you (others than Denys) try this patch, it should > solve the issue. And Denys, could you confirm (and if necessary doubl= e > check) that the kernel you saw this similar problem with is the pure > Linus' mainline, i.e., without any net-2.6.25 or mm bits please, if s= o, > that problem persists. And anyway, there were some fackets_out relate= d > problems reported as well and this doesn't help for that but I think = I've > lost track of who was seeing it due to large number of reports :-), c= ould > somebody refresh my memory because I currently don't have time to dig= it > up from archives (at least on this week). Thanks, applied on my test kernel, if there's no warnings I will just m= ute. > > > -- > i. > > -- > [PATCH] [TCP]: NewReno must count every skb while marking losses > > NewReno should add cnt per skb (as with FACK) instead of depending > on SACKED_ACKED bits which won't be set with it at all. > Effectively, NewReno should always exists after the first > iteration anyway (or immediately if there's already head in > lost_out. > > This was fixed earlier in net-2.6.25 but got reverted among other > stuff and I didn't notice that this is still necessary (actually > wasn't even considering this case while trying to figure out the > reports because I lived with different kind of code than it in > reality was). > > This should solve the WARN_ONs in TCP code that as a result of > this triggered multiple times in every place we check for this > invariant. > > Special thanks to Dave Young and > Krishna Kumar2 for trying with my debug > patches. > > Signed-off-by: Ilpo J=E4rvinen > --- > net/ipv4/tcp_input.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c > index 295490e..aa409a5 100644 > --- a/net/ipv4/tcp_input.c > +++ b/net/ipv4/tcp_input.c > @@ -2156,7 +2156,7 @@ static void tcp_mark_head_lost(struct sock *sk,= int packets, int fast_rexmit) > tp->lost_skb_hint =3D skb; > tp->lost_cnt_hint =3D cnt; > > - if (tcp_is_fack(tp) || > + if (tcp_is_fack(tp) || tcp_is_reno(tp) || > (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) > cnt +=3D tcp_skb_pcount(skb); > > -- > 1.5.2.2 >