On 09/10/2013 04:09 PM, J. Bruce Fields wrote: > On Sat, Sep 07, 2013 at 10:44:00PM +0200, Toralf Förster wrote: >> Today I run latest git tree with a patched UML (this patch + one for xterm issues) and got 2 times a core dump >> when I fuzzy test an UML machine with a nearly identical scenario as already described but just shutdowned >> both UML images instead of shooting one of it in the head. > > This is a slightly different test case, so for now it sounds like this > could be a preexisting problem, not a regression? > Yes, pre-existing. I'm trying to bisect it, the issue is already in 7d3107d. But every attempt to get the first bad commit before that commit id failed till now. I started many attempts between v3.10 and 7d3107d. I could not reproduce that issue 100% in that interval. In that interval either all tested commits doesn't show the issue or the NFS client hangs during the stop of NFS service infinitely - and counting that as a "bad" commit doesn't work. FWIW a single test case currently takes 2 1/2 hour and even then I do not fully trust the result (except for a bad commit, that's clear. > --b. > >> >> I'll probably need time to figure out a test case, but just as a pre-info here's the back trace: >> >> tfoerste@n22 ~ $ gdb --core=/mnt/ramdisk/core /usr/local/bin/linux-v3.11-7550-g768c9d3 -n -batch -ex bt >> >> warning: core file may not match specified executable file. >> [New LWP 7470] >> [New LWP 7479] >> [New LWP 7477] >> [New LWP 7478] >> Core was generated by `/usr/local/bin/linux-v3.11-7550-g768c9d3 earlyprintk ubda=/home/tfoerste/virtua'. >> Program terminated with signal 6, Aborted. >> #0 0xb77be424 in __kernel_vsyscall () >> #0 0xb77be424 in __kernel_vsyscall () >> #1 0x083aada5 in kill () >> #2 0x0807163d in uml_abort () at arch/um/os-Linux/util.c:93 >> #3 0x08071925 in os_dump_core () at arch/um/os-Linux/util.c:138 >> #4 0x080613a7 in panic_exit (self=0x85b1518 <panic_exit_notifier>, unused1=0, unused2=0x85e76e0 <buf.15920>) at arch/um/kernel/um_arch.c:240 >> #5 0x0809a398 in notifier_call_chain (nl=0x0, val=0, v=0x85e76e0 <buf.15920>, nr_to_call=-2, nr_calls=0x0) at kernel/notifier.c:93 >> #6 0x0809a4e3 in __atomic_notifier_call_chain (nr_calls=<optimized out>, nr_to_call=<optimized out>, v=<optimized out>, val=<optimized out>, nh=<optimized out>) at kernel/notifier.c:182 >> #7 atomic_notifier_call_chain (nh=0x85e76c4 <panic_notifier_list>, val=0, v=0x85e76e0 <buf.15920>) at kernel/notifier.c:191 >> #8 0x08408628 in panic (fmt=0x0) at kernel/panic.c:128 >> #9 0x081131c9 in shrink_dcache_for_umount_subtree (dentry=0x428028f0) at fs/dcache.c:941 >> #10 0x08113948 in shrink_dcache_for_umount (sb=0x463b8000) at fs/dcache.c:1002 >> #11 0x08101677 in generic_shutdown_super (sb=0x463b8000) at fs/super.c:404 >> #12 0x08102395 in kill_anon_super (sb=0x0) at fs/super.c:875 >> #13 0x081d3ff8 in nfs_kill_super (s=0x0) at fs/nfs/super.c:2598 >> #14 0x0810153a in deactivate_locked_super (s=0x463b8000) at fs/super.c:294 >> #15 0x081015d1 in deactivate_super (s=0x463b8000) at fs/super.c:319 >> #16 0x08119c0c in mntfree (mnt=<optimized out>) at fs/namespace.c:891 >> #17 mntput_no_expire (mnt=0x0) at fs/namespace.c:929 >> #18 0x0811b195 in SYSC_umount (flags=<optimized out>, name=<optimized out>) at fs/namespace.c:1335 >> #19 SyS_umount (name=134633856, flags=2) at fs/namespace.c:1305 >> #20 0x080618e2 in handle_syscall (r=0x498be5d4) at arch/um/kernel/skas/syscall.c:35 >> #21 0x08073c0d in handle_trap (local_using_sysemu=<optimized out>, regs=<optimized out>, pid=<optimized out>) at arch/um/os-Linux/skas/process.c:198 >> #22 userspace (regs=0x498be5d4) at arch/um/os-Linux/skas/process.c:431 >> #23 0x0805e65c in fork_handler () at arch/um/kernel/process.c:160 >> #24 0x00000000 in ?? () >> >> >> >> -- >> MfG/Sincerely >> Toralf Förster >> pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3 > -- MfG/Sincerely Toralf Förster pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html