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authorJuri Lelli <juri.lelli@arm.com>2014-09-19 11:22:39 +0200
committerIngo Molnar <mingo@kernel.org>2014-09-24 14:46:56 +0200
commita5e7be3b28a235108c59561bea55eea1072b23b0 (patch)
tree57e8b7c8c7059cf4775a5742ea0cfd69e71a04ee /kernel/sched/sched.h
parentsched/numa: Kill the wrong/dead TASK_DEAD check in task_numa_fault() (diff)
downloadlinux-a5e7be3b28a235108c59561bea55eea1072b23b0.tar.xz
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sched/deadline: Clear dl_entity params when setscheduling to different class
When a task is using SCHED_DEADLINE and the user setschedules it to a different class its sched_dl_entity static parameters are not cleaned up. This causes a bug if the user sets it back to SCHED_DEADLINE with the same parameters again. The problem resides in the check we perform at the very beginning of dl_overflow(): if (new_bw == p->dl.dl_bw) return 0; This condition is met in the case depicted above, so the function returns and dl_b->total_bw is not updated (the p->dl.dl_bw is not added to it). After this, admission control is broken. This patch fixes the thing, properly clearing static parameters for a task that ceases to use SCHED_DEADLINE. Reported-by: Daniele Alessandrelli <daniele.alessandrelli@gmail.com> Reported-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Reported-by: Vincent Legout <vincent@legout.info> Tested-by: Luca Abeni <luca.abeni@unitn.it> Tested-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Tested-by: Vincent Legout <vincent@legout.info> Signed-off-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Fabio Checconi <fchecconi@gmail.com> Cc: Dario Faggioli <raistlin@linux.it> Cc: Michael Trimarchi <michael@amarulasolutions.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1411118561-26323-2-git-send-email-juri.lelli@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/sched.h')
-rw-r--r--kernel/sched/sched.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 1bc6aad1391a..76f3a38a401c 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -130,6 +130,9 @@ struct rt_bandwidth {
u64 rt_runtime;
struct hrtimer rt_period_timer;
};
+
+void __dl_clear_params(struct task_struct *p);
+
/*
* To keep the bandwidth of -deadline tasks and groups under control
* we need some place where: