root@ise-test:/proc/450# uname -a Linux ise-test 2.6.38 #6 SMP PREEMPT Tue Apr 12 11:25:19 CEST 2011 x86_64 GNU/Linux root@ise-test:/proc/450# cat status Name: iknowthis State: D (disk sleep) Tgid: 450 Pid: 450 PPid: 1 TracerPid: 0 Uid: 1001 1001 1001 1001 Gid: 1001 1001 1001 1001 FDSize: 64 Groups: 1001 VmPeak: 12292 kB VmSize: 11116 kB VmLck: 44 kB VmHWM: 1904 kB VmRSS: 1324 kB VmData: 712 kB VmStk: 7616 kB VmExe: 160 kB VmLib: 2556 kB VmPTE: 28 kB VmSwap: 0 kB Threads: 1 SigQ: 785/16382 SigPnd: 0000000000000100 ?? SIGKILL ShdPnd: 0000000000000100 SigBlk: 0000000000000000 SigIgn: 0000000001001000 SigCgt: 0000000000000000 CapInh: 0000000000000000 CapPrm: 0000000000000000 CapEff: 0000000000000000 CapBnd: ffffffffffffffff Cpus_allowed: ff Cpus_allowed_list: 0-7 Mems_allowed: 00000000,00000001 Mems_allowed_list: 0 voluntary_ctxt_switches: 2303 nonvoluntary_ctxt_switches: 287 # cat wchan call_rwsem_down_write_failed root@ise-test:/proc/450# ls -l fd/ total 0 lrwx------ 1 test test 64 2011-04-12 12:17 0 -> /dev/pts/1 lrwx------ 1 test test 64 2011-04-12 12:17 1 -> /dev/pts/1 lr-x------ 1 test test 64 2011-04-12 12:17 10 -> /dev/shm/??(?x??Ӑd?=R1Y ??C??\:?i}?)B????d!0?E?g??? (deleted) lr-x------ 1 test test 64 2011-04-12 12:17 11 -> /home l-wx------ 1 test test 64 2011-04-12 12:17 12 -> /var/lock/?=ݾ+????7???????@N??eѵj?P5´?~?w?PomYK??ny_???ulv? l-wx------ 1 test test 64 2011-04-12 12:17 13 -> /var/lock/) ?????????`v?-ҩuQ?????O?갈????Nnhc ??N?I?G???Ȩ??????!?{V??ssifs>???N????q?I?ل??!T>??3??z?tI4?B?X"T??ӓ (deleted) lr-x------ 1 test test 64 2011-04-12 12:17 14 -> /dev/shm/????]?1???B??c?T?eu????X????????????^???~jF???-?e?m?u l-wx------ 1 test test 64 2011-04-12 12:17 15 -> /var/lock/?笉˩F?q?jAHu??o ??Ǘu???????O?;B??QmSX???p?߃?S??w{??,?)???D??V???q?ø#?? lrwx------ 1 test test 64 2011-04-12 12:17 2 -> /dev/pts/1 lr-x------ 1 test test 64 2011-04-12 12:17 3 -> /dev/urandom lrwx------ 1 test test 64 2011-04-12 12:17 4 -> anon_inode:[timerfd] lr-x------ 1 test test 64 2011-04-12 12:17 5 -> /sys/kernel/debug/asoc/codecs lr-x------ 1 test test 64 2011-04-12 12:17 6 -> /proc/i2o l-wx------ 1 test test 64 2011-04-12 12:17 7 -> /dev/shm/?????z?u????????Z???n"?d?i3Ǘ??????E??^?????O?}7+?[??#!???&A?R~&??????(։?w???\w?c"E?&?"?嵿?)ʝ?+?-?M_??R?Y??R???6?FAhGu?R?6?k??????l?B?w??~?Ց?^??i?????[.? (deleted) lr-x------ 1 test test 64 2011-04-12 12:17 8 -> /var/lock/?5?ݕ?C???\#]???b-??????q=???,?v?]???????a?i???ΐ??\??HTb??c?@\0?M???????????|???x?X?[{&+?$?X???????9? l-wx------ 1 test test 64 2011-04-12 12:17 9 -> /var/lock/BF}???P(??`?ϰ??.??? root@ise-test:/proc/450# for x in fdinfo/*; do echo == $x ==; cat "$x"; done == fdinfo/0 == pos: 0 flags: 0100002 == fdinfo/1 == pos: 0 flags: 0100002 == fdinfo/10 == pos: 1351256300595494888 flags: 024240004004 == fdinfo/11 == pos: 1084786014 flags: 04040620010 == fdinfo/12 == pos: 1811044362 flags: 0100001 == fdinfo/13 == pos: 3226073394 flags: 0100001 == fdinfo/14 == pos: 803230536 flags: 020026710024 == fdinfo/15 == pos: 1103604314 flags: 0100001 == fdinfo/2 == pos: 0 flags: 0100002 == fdinfo/3 == pos: 0 flags: 00 == fdinfo/4 == pos: 0 flags: 02 == fdinfo/5 == pos: 7081918111360778253 flags: 020200004044 == fdinfo/6 == pos: 2075525754 flags: 0200200000 == fdinfo/7 == pos: 2145128454 flags: 0100001 == fdinfo/8 == pos: 1343491212 flags: 020471010020 == fdinfo/9 == pos: 1073743904 flags: 01100001 (gdb) attach 450 Attaching to process 450 [hangs] root@ise-test:~# cd /proc/450/ root@ise-test:/proc/450# ls [hangs, but it worked] root@ise-test:~# cat /proc/mounts rootfs / rootfs rw 0 0 /dev/root / ext4 rw,relatime,errors=remount-ro,barrier=1,data=ordered 0 0 devtmpfs /dev devtmpfs rw,relatime,size=1981824k,nr_inodes=495456,mode=755 0 0 none /proc proc rw,nosuid,nodev,noexec,relatime 0 0 none /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0 none /proc/sys/fs/binfmt_misc binfmt_misc rw,nosuid,nodev,noexec,relatime 0 0 none /sys/fs/fuse/connections fusectl rw,relatime 0 0 none /sys/kernel/debug debugfs rw,relatime 0 0 none /sys/kernel/security securityfs rw,relatime 0 0 none /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0 none /dev/shm tmpfs rw,nosuid,nodev,relatime 0 0 none /var/run tmpfs rw,nosuid,relatime,mode=755 0 0 none /var/lock tmpfs rw,nosuid,nodev,noexec,relatime 0 0 root@ise-test:~# ls -l /proc/450/root lrwxrwxrwx 1 test test 0 2011-04-12 12:17 /proc/450/root -> / root@ise-test:~# cat /proc/450/smaps [hangs] root@ise-test:~# cat /proc/450/syscall 7 0xac4 0xff806d88 0x40000000 0x96 0xac5 0xff806da8 0xff806d18 0xffffe430 [0]kdb> bt Stack traceback for pid 450 0xffff880118905cc0 450 1 0 0 D 0xffff880118906140 iknowthis ffff88011da8fb58 0000000000000086 ffff88012bffbe0a 0000000000000001 ffff880132373331 ffff88011da8e000 ffff88011da8e000 ffff880118905cc0 ffff88011da8e010 ffff880118906078 ffff88011da8ffd8 ffff88011da8ffd8 Call Trace: [] rwsem_down_failed_common+0xc5/0x160 [] rwsem_down_write_failed+0x13/0x20 [] call_rwsem_down_write_failed+0x13/0x20 [] ? down_write+0x25/0x30 [] do_coredump+0x139/0xbb0 [] ? sub_preempt_count+0xa9/0xe0 [] ? __dequeue_signal+0xf4/0x190 [] get_signal_to_deliver+0x29b/0x4a0 [] do_signal+0x75/0x7b0 [] ? compat_sys_wait4+0x97/0xe0 [] ? do_fork+0xe2/0x370 [] do_notify_resume+0x65/0x90 [] ? trace_hardirqs_on_thunk+0x3a/0x3c [] int_signal+0x12/0x17 [0]kdb> btc 0 Stack traceback for pid 23592 0xffff880112c04590 23592 1 1 0 R 0xffff880112c04a10 *iknowthis ffff8800cfc03dc8 0000000000000018 Call Trace: <#DB> <> [] ? __handle_sysrq+0x129/0x190 [] ? handle_sysrq+0x26/0x30 [] ? serial8250_handle_port+0x21d/0x320 [] ? serial8250_interrupt+0x9b/0x140 [] ? handle_IRQ_event+0x68/0x1b0 [] ? move_native_irq+0x15/0x70 [] ? handle_edge_irq+0xbe/0x170 [] ? handle_irq+0x49/0xa0 [] ? do_IRQ+0x5d/0xe0 [] ? ret_from_intr+0x0/0x1a [] ? do_mlock_pages+0x78/0x150 [] ? do_mlock_pages+0x78/0x150 [] ? sys_mlock+0x11c/0x130 [] ? ia32_sysret+0x0/0x5 [0]kdb> btc 1 Stack traceback for pid 15223 0xffff88011ebb4590 15223 5594 1 1 R 0xffff88011ebb4a10 iknowthis ffff88011e529c48 0000000000000018 Call Trace: [0]kdb> summary sysname Linux release 2.6.38 version #6 SMP PREEMPT Tue Apr 12 11:25:19 CEST 2011 machine x86_64 nodename ise-test domainname (none) ccversion CCVERSION date 2011-04-12 10:24:42 tz_minuteswest -120 uptime 00:42 load avg 38.13 35.98 28.81 MemTotal: 992186 kB MemFree: 899924 kB Buffers: 5411 kB after go in kdb, and another kdb session: [0]kdb> btc 0 Stack traceback for pid 15802 0xffff88011e818000 15802 1 1 0 R 0xffff88011e818480 *iknowthis ffff8800cfc03dc8 0000000000000018 Call Trace: <#DB> <> [] ? __handle_sysrq+0x129/0x190 [] ? handle_sysrq+0x26/0x30 [] ? serial8250_handle_port+0x21d/0x320 [] ? serial8250_interrupt+0x9b/0x140 [] ? handle_IRQ_event+0x68/0x1b0 [] ? move_native_irq+0x15/0x70 [] ? handle_edge_irq+0xbe/0x170 [] ? handle_irq+0x49/0xa0 [] ? do_IRQ+0x5d/0xe0 [] ? ret_from_intr+0x0/0x1a [] ? restore_args+0x0/0x30 [] ? __mlock_vma_pages_range+0x9d/0xc0 [] ? __mlock_vma_pages_range+0x83/0xc0 [] ? do_mlock_pages+0x78/0x150 [] ? sys_mlock+0x11c/0x130 [] ? ia32_sysret+0x0/0x5 and another go/kdb: [0]kdb> btc 0 Stack traceback for pid 15802 0xffff88011e818000 15802 1 1 0 R 0xffff88011e818480 *iknowthis ffff8800cfc03dc8 0000000000000018 Call Trace: <#DB> <> [] ? __handle_sysrq+0x129/0x190 [] ? handle_sysrq+0x26/0x30 [] ? serial8250_handle_port+0x21d/0x320 [] ? serial8250_interrupt+0x9b/0x140 [] ? handle_IRQ_event+0x68/0x1b0 [] ? move_native_irq+0x15/0x70 [] ? handle_edge_irq+0xbe/0x170 [] ? handle_irq+0x49/0xa0 [] ? do_IRQ+0x5d/0xe0 [] ? ret_from_intr+0x0/0x1a [] ? do_mlock_pages+0x92/0x150 [] ? do_mlock_pages+0x78/0x150 [] ? sys_mlock+0x11c/0x130 [] ? ia32_sysret+0x0/0x5