From 82b95800b256205cff2eeab5bbd03430d2d0f20d Mon Sep 17 00:00:00 2001 From: Boris Ostrovsky Date: Mon, 17 Feb 2014 09:12:33 -0500 Subject: [PATCH] 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 Cc: Juri Lelli Cc: Steven Rostedt Reported-by: Konrad Rzeszutek Wilk Signed-off-by: Boris Ostrovsky Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1392646353-1874-1-git-send-email-boris.ostrovsky@oracle.com Signed-off-by: Thomas Gleixner --- kernel/sched/cpudeadline.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c index 045fc74e3f09..5b8838b56d1c 100644 --- a/kernel/sched/cpudeadline.c +++ b/kernel/sched/cpudeadline.c @@ -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) { - 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)) { cp->elements[idx].dl = new_dl; @@ -117,7 +117,7 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p, } out: - WARN_ON(best_cpu > num_present_cpus() && best_cpu != -1); + WARN_ON(!cpu_present(best_cpu) && best_cpu != -1); 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; unsigned long flags; - WARN_ON(cpu > num_present_cpus()); + WARN_ON(!cpu_present(cpu)); raw_spin_lock_irqsave(&cp->lock, flags); old_idx = cp->cpu_to_idx[cpu]; -- 2.30.2