From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754487AbYAXJyg (ORCPT ); Thu, 24 Jan 2008 04:54:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753289AbYAXJyZ (ORCPT ); Thu, 24 Jan 2008 04:54:25 -0500 Received: from courier.cs.helsinki.fi ([128.214.9.1]:48946 "EHLO mail.cs.helsinki.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752863AbYAXJyX (ORCPT ); Thu, 24 Jan 2008 04:54:23 -0500 Date: Thu, 24 Jan 2008 11:54:18 +0200 (EET) From: "=?ISO-8859-1?Q?Ilpo_J=E4rvinen?=" X-X-Sender: ijjarvin@kivilampi-30.cs.helsinki.fi To: Dave Young , Kamalesh Babulal , Krishna Kumar2 , Denys Fedoryshchenko , David Miller cc: LKML , Netdev , Andrew Morton Subject: Re: 2.6.24-rc8-mm1 : net tcp_input.c warnings In-Reply-To: Message-ID: References:

<20080122.190137.206066966.davem@davemloft.net>

MIME-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="-696243703-1594222684-1201168458=:31652" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. ---696243703-1594222684-1201168458=:31652 Content-Type: TEXT/PLAIN; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT 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 <= 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+0x122/0x150() > 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 psmouse > 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 > ======================= > ---[ 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 psmouse > 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 > ======================= > ---[ end trace 14b601818e6903ac ]--- ...But this no longer is, and even more, L: 5 is not valid state at this 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 forgot 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 double 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 so, that problem persists. And anyway, there were some fackets_out related 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 :-), could somebody refresh my memory because I currently don't have time to dig it up from archives (at least on this week). -- 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 Järvinen --- 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 = skb; tp->lost_cnt_hint = cnt; - if (tcp_is_fack(tp) || + if (tcp_is_fack(tp) || tcp_is_reno(tp) || (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) cnt += tcp_skb_pcount(skb); -- 1.5.2.2 ---696243703-1594222684-1201168458=:31652--