Commit 82b95800 authored by Boris Ostrovsky's avatar Boris Ostrovsky Committed by Thomas Gleixner
Browse files

sched/deadline: Test for CPU's presence explicitly 



A hot-removed CPU may have ID that is numerically larger than the number of
existing CPUs in the system (e.g. we can unplug CPU 4 from a system that
has CPUs 0, 1 and 4).

Thus the WARN_ONs should check whether the CPU in question is currently
present, not whether its ID value is less than num_present_cpus().

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Reported-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392646353-1874-1-git-send-email-boris.ostrovsky@oracle.com


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 6d35ab48

kernel/sched/cpudeadline.c

+3 −3
Original line number Original line Diff line number Diff line
@@ -70,7 +70,7 @@ static void cpudl_heapify(struct cpudl *cp, int idx) 




static void cpudl_change_key(struct cpudl *cp, int idx, u64 new_dl)

static void cpudl_change_key(struct cpudl *cp, int idx, u64 new_dl)

{

{

	WARN_ON(idx > num_present_cpus() || idx == IDX_INVALID);

	WARN_ON(!cpu_present(idx) || idx == IDX_INVALID);





	if (dl_time_before(new_dl, cp->elements[idx].dl)) {

	if (dl_time_before(new_dl, cp->elements[idx].dl)) {

		cp->elements[idx].dl = new_dl;

		cp->elements[idx].dl = new_dl;
@@ -117,7 +117,7 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p, 
	}

	}





out:

out:

	WARN_ON(best_cpu > num_present_cpus() && best_cpu != -1);

	WARN_ON(!cpu_present(best_cpu) && best_cpu != -1);





	return best_cpu;

	return best_cpu;

}

}
@@ -137,7 +137,7 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid) 
	int old_idx, new_cpu;

	int old_idx, new_cpu;

	unsigned long flags;

	unsigned long flags;





	WARN_ON(cpu > num_present_cpus());

	WARN_ON(!cpu_present(cpu));





	raw_spin_lock_irqsave(&cp->lock, flags);

	raw_spin_lock_irqsave(&cp->lock, flags);

	old_idx = cp->cpu_to_idx[cpu];

	old_idx = cp->cpu_to_idx[cpu];