Messages in this thread Patch in this message | | | From | Valentin Schneider <> | Subject | [PATCH 2/2] lib/smp_processor_id: Use is_percpu_thread() instead of nr_cpus_allowed | Date | Mon, 10 May 2021 16:10:24 +0100 |
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From: Yejune Deng <yejune.deng@gmail.com>
is_percpu_thread() more elegantly handles SMP vs UP, and further checks the presence of PF_NO_SETAFFINITY. This lets us catch cases where check_preemption_disabled() can race with a concurrent sched_setaffinity().
Signed-off-by: Yejune Deng <yejune.deng@gmail.com> [Amended changelog] Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> --- lib/smp_processor_id.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c index 1c1dbd300325..046ac6297c78 100644 --- a/lib/smp_processor_id.c +++ b/lib/smp_processor_id.c @@ -19,11 +19,7 @@ unsigned int check_preemption_disabled(const char *what1, const char *what2) if (irqs_disabled()) goto out; - /* - * Kernel threads bound to a single CPU can safely use - * smp_processor_id(): - */ - if (current->nr_cpus_allowed == 1) + if (is_percpu_thread()) goto out; #ifdef CONFIG_SMP -- 2.25.1
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