)]}' { "log": [ { "commit": "cf2592f59c0e8ed4308adbdb2e0a88655379d579", "tree": "383b30bc13af8ce83e15825b041d8bb791ea4cea", "parents": [ "17406b82d621930cca8ccc1272cdac9a7dae8e40" ], "author": { "name": "Frederic Weisbecker", "email": "fweisbec@gmail.com", "time": "Tue Feb 10 16:52:37 2009 +0100" }, "committer": { "name": "Ingo Molnar", "email": "mingo@elte.hu", "time": "Wed Feb 11 11:04:16 2009 +0100" }, "message": "softlockup: ensure the task has been switched out once\n\nWhen we check if a task has been switched out since the last scan, we might\nhave a race condition on the following scenario:\n\n- the task is freshly created and scheduled\n\n- it puts its state to TASK_UNINTERRUPTIBLE and is not yet switched out\n\n- check_hung_task() scans this task and will report a false positive because\n t-\u003envcsw + t-\u003enivcsw \u003d\u003d t-\u003elast_switch_count \u003d\u003d 0\n\nAdd a check for such cases.\n\nSigned-off-by: Frederic Weisbecker \u003cfweisbec@gmail.com\u003e\nAcked-by: Mandeep Singh Baines \u003cmsb@google.com\u003e\nSigned-off-by: Ingo Molnar \u003cmingo@elte.hu\u003e\n" }, { "commit": "17406b82d621930cca8ccc1272cdac9a7dae8e40", "tree": "224c8b0b7c78a5467175fe10e116bdc6b73495ea", "parents": [ "94be52dc075a32af4aa73d7e10f68734d62d6af2" ], "author": { "name": "Mandeep Singh Baines", "email": "msb@google.com", "time": "Fri Feb 06 15:37:47 2009 -0800" }, "committer": { "name": "Ingo Molnar", "email": "mingo@elte.hu", "time": "Mon Feb 09 11:03:49 2009 +0100" }, "message": "softlockup: remove timestamp checking from hung_task\n\nImpact: saves sizeof(long) bytes per task_struct\n\nBy guaranteeing that sysctl_hung_task_timeout_secs have elapsed between\ntasklist scans we can avoid using timestamps.\n\nSigned-off-by: Mandeep Singh Baines \u003cmsb@google.com\u003e\nSigned-off-by: Ingo Molnar \u003cmingo@elte.hu\u003e\n" }, { "commit": "94be52dc075a32af4aa73d7e10f68734d62d6af2", "tree": "70e4f2bf93dda15a27b79baf49bbfd3fc5982ba1", "parents": [ "ce9dbe244bf2063c41792e40dae7745957b118e0" ], "author": { "name": "Mandeep Singh Baines", "email": "msb@google.com", "time": "Thu Feb 05 09:56:08 2009 -0800" }, "committer": { "name": "Ingo Molnar", "email": "mingo@elte.hu", "time": "Thu Feb 05 19:55:31 2009 +0100" }, "message": "softlockup: convert read_lock in hung_task to rcu_read_lock\n\nSince the tasklist is protected by rcu list operations, it is safe\nto convert the read_lock()s to rcu_read_lock().\n\nSuggested-by: Peter Zijlstra \u003ca.p.zijlstra@chello.nl\u003e\nSigned-off-by: Mandeep Singh Baines \u003cmsb@google.com\u003e\nSigned-off-by: Ingo Molnar \u003cmingo@elte.hu\u003e\n" }, { "commit": "ce9dbe244bf2063c41792e40dae7745957b118e0", "tree": "a6278f5f012d2284aecbeb17bf5371d4864963d3", "parents": [ "5e54f5986a579b8445aa1d5ad3435c2cf7568bed" ], "author": { "name": "Mandeep Singh Baines", "email": "msb@google.com", "time": "Wed Feb 04 20:35:48 2009 -0800" }, "committer": { "name": "Ingo Molnar", "email": "mingo@elte.hu", "time": "Thu Feb 05 19:54:57 2009 +0100" }, "message": "softlockup: check all tasks in hung_task\n\nImpact: extend the scope of hung-task checks\n\nChanged the default value of hung_task_check_count to PID_MAX_LIMIT.\nhung_task_batch_count added to put an upper bound on the critical\nsection. Every hung_task_batch_count checks, the rcu lock is never\nheld for a too long time.\n\nKeeping the critical section small minimizes time preemption is disabled\nand keeps rcu grace periods small.\n\nTo prevent following a stale pointer, get_task_struct is called on g and t.\nTo verify that g and t have not been unhashed while outside the critical\nsection, the task states are checked.\n\nThe design was proposed by Frédéric Weisbecker.\n\nSigned-off-by: Mandeep Singh Baines \u003cmsb@google.com\u003e\nSuggested-by: Frédéric Weisbecker \u003cfweisbec@gmail.com\u003e\nAcked-by: Andrew Morton \u003cakpm@linux-foundation.org\u003e\nSigned-off-by: Ingo Molnar \u003cmingo@elte.hu\u003e\n" }, { "commit": "603a148f434742fff08273207ffa44176cad13a1", "tree": "e0c051efd07a7b51390e13169f4c78a29c676fc1", "parents": [ "af432eb1cc3178ec7109aca2283aafb1c12ccac1" ], "author": { "name": "Mandeep Singh Baines", "email": "msb@google.com", "time": "Sat Jan 17 10:31:48 2009 -0800" }, "committer": { "name": "Ingo Molnar", "email": "mingo@elte.hu", "time": "Sun Jan 18 19:20:17 2009 +0100" }, "message": "softlockup: fix potential race in hung_task when resetting timeout\n\nImpact: fix potential false panic\n\nA potential race exists if sysctl_hung_task_timeout_secs is reset to 0\nwhile inside check_hung_uniterruptible_tasks(). If check_task() is\nentered, a comparison with 0 will result in a false hung_task being\ndetected.\n\nIf sysctl_hung_task_panic is set, the system will panic.\n\nSigned-off-by: Mandeep Singh Baines \u003cmsb@google.com\u003e\nSigned-off-by: Ingo Molnar \u003cmingo@elte.hu\u003e\n" }, { "commit": "e162b39a368f0401e41b558f430c354d12a85b37", "tree": "3fb7e4d48f398d62e5074e7e3dd183cc54f59820", "parents": [ "c903ff837909ccada51243307d4239f86af40179" ], "author": { "name": "Mandeep Singh Baines", "email": "msb@google.com", "time": "Thu Jan 15 11:08:40 2009 -0800" }, "committer": { "name": "Ingo Molnar", "email": "mingo@elte.hu", "time": "Fri Jan 16 14:06:04 2009 +0100" }, "message": "softlockup: decouple hung tasks check from softlockup detection\n\nDecoupling allows:\n\n* hung tasks check to happen at very low priority\n\n* hung tasks check and softlockup to be enabled/disabled independently\n at compile and/or run-time\n\n* individual panic settings to be enabled disabled independently\n at compile and/or run-time\n\n* softlockup threshold to be reduced without increasing hung tasks\n poll frequency (hung task check is expensive relative to softlock watchdog)\n\n* hung task check to be zero over-head when disabled at run-time\n\nSigned-off-by: Mandeep Singh Baines \u003cmsb@google.com\u003e\nSigned-off-by: Ingo Molnar \u003cmingo@elte.hu\u003e\n" } ] }