Currently preempt_count() is always a non-negative int on all archs (PREEMPT_NEED_RESCHED archs will mask out the MSB when return preempt_count()), hence the checking in __cant_migrate() is in fact just checking whether preempt_count() is 0 or not. In a future change, we are going to use all the 32 bits of preempt_count(), which would make negative int values possible from preempt_count(). Therefore convert the "> 0" comparison into a zero checking to prepare for the future change. No functional changes are intended.
Signed-off-by: Boqun Feng <[email protected]> --- kernel/sched/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 75dba7cc09bd..636e6a15f104 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -9207,7 +9207,7 @@ void __cant_migrate(const char *file, int line) if (!IS_ENABLED(CONFIG_PREEMPT_COUNT)) return; - if (preempt_count() > 0) + if (preempt_count()) return; if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) -- 2.50.1 (Apple Git-155)
