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authorJuri Lelli <juri.lelli@arm.com>2014-10-07 12:52:11 +0400
committerIngo Molnar <mingo@kernel.org>2014-10-28 12:48:00 +0300
commitf82f80426f7afcf55953924e71555984a4bd6ce6 (patch)
tree3a3e15c85f04c11d8f9bc0708b4c8ca439d3431b /include/linux/sched.h
parent7f51412a415d87ea8598d14722fb31e4f5701257 (diff)
downloadlinux-f82f80426f7afcf55953924e71555984a4bd6ce6.tar.xz
sched/deadline: Ensure that updates to exclusive cpusets don't break AC
How we deal with updates to exclusive cpusets is currently broken. As an example, suppose we have an exclusive cpuset composed of two cpus: A[cpu0,cpu1]. We can assign SCHED_DEADLINE task to it up to the allowed bandwidth. If we want now to modify cpusetA's cpumask, we have to check that removing a cpu's amount of bandwidth doesn't break AC guarantees. This thing isn't checked in the current code. This patch fixes the problem above, denying an update if the new cpumask won't have enough bandwidth for SCHED_DEADLINE tasks that are currently active. Signed-off-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Li Zefan <lizefan@huawei.com> Cc: cgroups@vger.kernel.org Link: http://lkml.kernel.org/r/5433E6AF.5080105@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/sched.h')
-rw-r--r--include/linux/sched.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 1d1fa081d44f..320a9779f1b4 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2052,6 +2052,8 @@ static inline void tsk_restore_flags(struct task_struct *task,
task->flags |= orig_flags & flags;
}
+extern int cpuset_cpumask_can_shrink(const struct cpumask *cur,
+ const struct cpumask *trial);
extern int task_can_attach(struct task_struct *p,
const struct cpumask *cs_cpus_allowed);
#ifdef CONFIG_SMP