Date: Mon, 22 Nov 2004 09:45:07 -0500 From: "Simson L. Garfinkel" <simsong@csail.mit.edu> To: freebsd-current@freebsd.org Cc: robert@fledge.watson.org Subject: Page fault in FreeBSD 5.3 on IBM e325, Dual AMD64 2.2GHz, 4GB Message-ID: <1A70D4C2-3C95-11D9-A5BE-000A95DA91E2@csail.mit.edu>
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--Apple-Mail-15-420939675 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed I had precisely this same problem over the weekend moving from FreeBSD 5.3-RC1 to 5.3_RELENG. Other symptoms: network stack problems at boot (ntpdate didn't work until after the system was fully up.) Reverting to RC1 seems to have solved the problem. On Mon, 22 Nov 2004, Ganbold wrote: > Fatal trap 12: page fault while in kernel mode > cpuid = 1; apic id = 01 > fault virtual address = 0x18 > fault code = supervisor read, page not present > instruction pointer = 0x8:0xffffffff80277fc0 > stack pointer = 0x10:0xffffffffb36ab830 > frame pointer = 0x10:0xffffffffb36ab890 > code segment = base 0x0, limit 0xfffff, type 0x1b > = DPL 0, pres 1, long 1, def32 0, gran 1 > processor eflags = interrupt enabled, resume, IOPL = 0 > current process = 44 (swi1: net) > [thread 100044] > Stopped at m_copym+0x190: incl %ecx <...> > ------------------------------------------------------------------------ -------------------------------- > > It seems to me the problem is related to network stack and threading. > Am I right? How to solve this problem? I've seen reports of this problem with and without debug.mpsafenet=1, which suggests it is a network stack bug but not specific to locking. I've also seen reports that disabling TCP SACK will make the problem go away, which would be good to confirm. I spent the weekend building up some more expertise in TCP and reading a lot of TCP code, and hope to look at this problem in more detail today. You may want to try turning off TCP sack using net.inet.tcp.sack.enable=0 in sysctl.conf (or loader.conf). Robert N M Watson FreeBSD Core Team, TrustedBSD Projects robert at fledge.watson.org Principal Research Scientist, McAfee Research --Apple-Mail-15-420939675--
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