Date: Thu, 29 Dec 2011 21:25:02 +0100 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: John Baldwin <jhb@freebsd.org> Cc: Andre Oppermann <andre@freebsd.org>, freebsd-net@freebsd.org, =?utf-8?B?0JrQvtC90YzQutC+0LIg0JXQstCz0LXQvdC40Lk=?= <kes-kes@yandex.ru>, freebsd-current@freebsd.org, Kostik Belousov <kostikbel@gmail.com>, Lawrence Stewart <lstewart@freebsd.org> Subject: Re: 9.0-RC1 panic in tcp_input: negative winow. Message-ID: <20111229202501.GA1889@garage.freebsd.pl> In-Reply-To: <201112291112.59912.jhb@freebsd.org> References: <20111022084931.GD1697@garage.freebsd.pl> <201112200952.44690.jhb@freebsd.org> <1632420869.20111225180133@yandex.ru> <201112291112.59912.jhb@freebsd.org>
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--y0ulUmNC+osPPQO6 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Dec 29, 2011 at 11:12:59AM -0500, John Baldwin wrote: > On Sunday, December 25, 2011 11:01:33 am =D0=9A=D0=BE=D0=BD=D1=8C=D0=BA= =D0=BE=D0=B2 =D0=95=D0=B2=D0=B3=D0=B5=D0=BD=D0=B8=D0=B9 wrote: > > =D0=97=D0=B4=D1=80=D0=B0=D0=B2=D1=81=D1=82=D0=B2=D1=83=D0=B9=D1=82=D0= =B5, John. > >=20 > > =D0=92=D1=8B =D0=BF=D0=B8=D1=81=D0=B0=D0=BB=D0=B8 20 =D0=B4=D0=B5=D0=BA= =D0=B0=D0=B1=D1=80=D1=8F 2011 =D0=B3., 16:52:44: > >=20 > > JB> On Saturday, December 17, 2011 6:21:27 pm Pawel Jakub Dawidek wrote: > > >> On Mon, Dec 12, 2011 at 11:00:23AM -0500, John Baldwin wrote: > > >> > An update. I've sent Pawel a testing patch to see if my hypothesi= s is correct > > >> > (www.freebsd.org/~jhb/patches/tcp_negwin_test.patch). If it is th= en I intend > > >> > to commit www.freebsd.org/~jhb/patches/tcp_negwin2.patch as the fi= x. > > >>=20 > > >> Unfortunately it paniced today. Take a look at: > > >>=20 > > >> http://people.freebsd.org/~pjd/misc/tcp_panic.jpg > >=20 > > JB> Ok, the one use case I was worried about is happening regularly bef= ore your > > JB> panic, so that is good. Can you use gdb to figure out which call to > > JB> tcp_output() is actually panic'ing? I wonder if it is this case: > >=20 > > JB> /* > > JB> * Return any desired output. > > JB> */ > > JB> if (needoutput || (tp->t_flags & TF_ACKNOW)) { > > JB> (void) tcp_output(tp); > > JB> /* XXX: Debug */ > > JB> KASSERT(SEQ_GEQ(tp->rcv_adv, tp->rcv_nxt), > > JB> ("tcp_input: negative window after ACK")); > >=20 > > JB> And if 'needoutput' is true, but TF_ACKNOW is not set, and tcp_outp= ut() decides > > JB> to not do anything. I've updated tcp_negwin_test.patch to not pani= c if that call > > JB> to tcp_output() doesn't actually send a packet. Please re-test. > >=20 > >=20 > > # uname -a > > FreeBSD meta-up 9.0-PRERELEASE FreeBSD 9.0-PRERELEASE #4: Sat Dec 24 13= :59:20 EET 2011 @:/usr/obj/usr/src/sys/KES_KERN_v10 i386 > >=20 > > rebooting once per day. Now I compile kernel with debug options. > > Can you advice me which and where I find debug info when it will > > reboting next time? so I can help to debug problem >=20 > Are you using the patch at the URL above (tcp_negwin_test.patch)? If not, > can you try applying that patch and seeing if you still get any panics? I applied 1.5 days ago, so far now panics and no other messages. I modified the patch a bit to not panic, but print a message when panic was suppose to happen. This box is too valuable for me to panic it too often. Because there were no debug messages I understand that the scenerio didn't happen yet and not that the problem is fixed, right? --=20 Pawel Jakub Dawidek http://www.wheelsystems.com FreeBSD committer http://www.FreeBSD.org Am I Evil? Yes, I Am! http://yomoli.com --y0ulUmNC+osPPQO6 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.14 (FreeBSD) iEYEARECAAYFAk78zJ0ACgkQForvXbEpPzR7RACcC+FS4llTUDG0av+6s26iwxl3 OOsAoPTMGfHUwJg+TgWm9gdJb+NXuIB5 =dh23 -----END PGP SIGNATURE----- --y0ulUmNC+osPPQO6--
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