https://github.com/torvalds/linux
Revision 5aa5050787f449e7eaef2c5ec93c7b357aa7dcdc authored by Luca Abeni on 16 October 2015, 08:06:21 UTC, committed by Ingo Molnar on 20 October 2015, 08:13:36 UTC
Commit: 9d5142624256 ("sched/deadline: Reduce rq lock contention by eliminating locking of non-feasible target") broke select_task_rq_dl() and find_lock_later_rq(), because it introduced a comparison between the local task's deadline and dl.earliest_dl.curr of the remote queue. However, if the remote runqueue does not contain any SCHED_DEADLINE task its earliest_dl.curr is 0 (always smaller than the deadline of the local task) and the remote runqueue is not selected for pushing. As a result, if an application creates multiple SCHED_DEADLINE threads, they will never be pushed to runqueues that do not already contain SCHED_DEADLINE tasks. This patch fixes the issue by checking if dl.dl_nr_running == 0. Signed-off-by: Luca Abeni <luca.abeni@unitn.it> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@linux.intel.com> Fixes: 9d5142624256 ("sched/deadline: Reduce rq lock contention by eliminating locking of non-feasible target") Link: http://lkml.kernel.org/r/1444982781-15608-1-git-send-email-luca.abeni@unitn.it Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Tip revision: 5aa5050787f449e7eaef2c5ec93c7b357aa7dcdc authored by Luca Abeni on 16 October 2015, 08:06:21 UTC
sched/deadline: Fix migration of SCHED_DEADLINE tasks
sched/deadline: Fix migration of SCHED_DEADLINE tasks
Tip revision: 5aa5050
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crypto | ||
drivers | ||
firmware | ||
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kernel | ||
lib | ||
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COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 94.9 KB |
Kbuild | -rw-r--r-- | 2.6 KB |
Kconfig | -rw-r--r-- | 252 bytes |
MAINTAINERS | -rw-r--r-- | 319.7 KB |
Makefile | -rw-r--r-- | 53.2 KB |
README | -rw-r--r-- | 18.2 KB |
REPORTING-BUGS | -rw-r--r-- | 7.3 KB |
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