Bug 12687

Summary: hang, won't allow new processes to be created
Product: Process Management Reporter: Folkert van Heusden (folkert)
Component: SchedulerAssignee: Ingo Molnar (mingo)
Status: CLOSED UNREPRODUCIBLE    
Severity: normal CC: alan, kernel
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: 2.6.28.1 Subsystem:
Regression: No Bisected commit-id:

Description Folkert van Heusden 2009-02-11 03:19:51 UTC 
Latest working kernel version: < 2.6.26
Earliest failing kernel version: 2.6.26
Distribution: Debian
Hardware Environment: Quadcore (intel core2duo), 4GB ram, 64bit, sata disk
Problem Description:
After a while (days, sometimes hours) the system sends the following messages to dmesg, then the system doesn't allow any forks. Most of the time it's a few of these messages, sometimes thousands (of the same).

[42265.700129] INFO: task cron:4841 blocked for more than 120 seconds.
[42265.700139] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[42265.700142] cron          D ffff88002802e700     0  4841   5367
[42265.700148]  ffff880065101dd8 0000000000000082 ffff880065101e8c
0000000000000292
[42265.700159]  ffff88009a990ab0 ffffffff80550340 ffff88009a990d28 0000000000000000 [42265.700168]  0000000000000296 ffff88012bc059c0 00000000000000d0
0000000000004111
[42265.700176] Call Trace:
[42265.700184]  [<ffffffff80464cb0>] schedule_timeout+0x1e/0xad 
[42265.700188]  [<ffffffff8046427f>] wait_for_common+0xc4/0x13d 
[42265.700194]  [<ffffffff8023a6fc>] default_wake_function+0x0/0xe [42265.700199]  [<ffffffff80241632>] do_fork+0x21e/0x285 
[42265.700202]  [<ffffffff80210dba>] system_call_fastpath+0x16/0x1b 
[42265.700206]  [<ffffffff80211247>] ptregscall_common+0x67/0xb0

[42265.700331] INFO: task cron:4845 blocked for more than 120 seconds.
[42265.700333] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[42265.700335] cron          D ffff88002802e700     0  4845   5367
[42265.700340]  ffff88008c407dd8 0000000000000082 ffff88008c407e8c
0000000000000292
[42265.700349]  ffff88009e14a100 ffffffff80550340 ffff88009e14a378 0000000000000000 [42265.700357]  ffffffff80465fb7 ffffffff802c073f 0000000800000001 ffff88009e14a100 
[42265.700365] Call Trace:
[42265.700368]  [<ffffffff80465fb7>] _spin_lock+0x5/0x7 
[42265.700373]  [<ffffffff802c073f>] dup_fd+0x216/0x2bf 
[42265.700378]  [<ffffffff80464cb0>] schedule_timeout+0x1e/0xad 
[42265.700381]  [<ffffffff8046427f>] wait_for_common+0xc4/0x13d 
[42265.700384]  [<ffffffff8023a6fc>] default_wake_function+0x0/0xe [42265.700388]  [<ffffffff80241632>] do_fork+0x21e/0x285 
[42265.700391]  [<ffffffff80210dba>] system_call_fastpath+0x16/0x1b 
[42265.700395]  [<ffffffff80211247>] ptregscall_common+0x67/0xb0