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