Messages in this thread | | | Date | Mon, 17 Feb 2014 16:49:26 +0100 | From | Juri Lelli <> | Subject | Re: [PATCH] sched/deadline: Test for CPU's presence explicitly |
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On 02/17/2014 03:50 PM, Peter Zijlstra wrote: > On Mon, Feb 17, 2014 at 09:12:33AM -0500, Boris Ostrovsky wrote: >> 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(). >> >> Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> >> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> > > Thanks!, please also always CC the author of the code in question. >
Thanks!
- Juri
>> --- >> 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 045fc74..5b8838b 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]; >> -- >> 1.8.1.4 >>
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