linux - Linux Kernel (branches are rebased on master from time to time)

Age	Commit message (Collapse)	Author	Files	Lines
2017-01-24	kernel/watchdog: prevent false hardlockup on overloaded system	Don Zickus	1	-0/+3
	On an overloaded system, it is possible that a change in the watchdog threshold can be delayed long enough to trigger a false positive. This can easily be achieved by having a cpu spinning indefinitely on a task, while another cpu updates watchdog threshold. What happens is while trying to park the watchdog threads, the hrtimers on the other cpus trigger and reprogram themselves with the new slower watchdog threshold. Meanwhile, the nmi watchdog is still programmed with the old faster threshold. Because the one cpu is blocked, it prevents the thread parking on the other cpus from completing, which is needed to shutdown the nmi watchdog and reprogram it correctly. As a result, a false positive from the nmi watchdog is reported. Fix this by setting a park_in_progress flag to block all lockups until the parking is complete. Fix provided by Ulrich Obergfell. [akpm@linux-foundation.org: s/park_in_progress/watchdog_park_in_progress/] Link: http://lkml.kernel.org/r/1481041033-192236-1-git-send-email-dzickus@redhat.com Signed-off-by: Don Zickus <dzickus@redhat.com> Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Cc: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-14	kernel/watchdog.c: move hardlockup detector to separate file	Babu Moger	1	-0/+227
	Separate hardlockup code from watchdog.c and move it to watchdog_hld.c. It is mostly straight forward. Remove everything inside CONFIG_HARDLOCKUP_DETECTORS. This code will go to file watchdog_hld.c. Also update the makefile accordigly. Link: http://lkml.kernel.org/r/1478034826-43888-3-git-send-email-babu.moger@oracle.com Signed-off-by: Babu Moger <babu.moger@oracle.com> Acked-by: Don Zickus <dzickus@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Andi Kleen <andi@firstfloor.org> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Josh Hunt <johunt@akamai.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>