On Mon, 2021-07-19 at 10:26 +0800, chao.qin@xxxxxxxxx wrote: > From: Chao Qin <chao.qin@xxxxxxxxx> > > There is msleep in pr_flush(). If call WARN() in the early boot > stage such as in early_initcall, pr_flush() will run into msleep > when process scheduler is not ready yet. And then the system will > sleep forever. > > Before the system_state is SYSTEM_RUNNING, make sure DO NOT sleep > in pr_flush(). Makes sense, thanks. > diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c [] > @@ -3620,7 +3620,8 @@ bool pr_flush(int timeout_ms, bool reset_on_progress) > u64 diff; > u64 seq; > > - may_sleep = (preemptible() && !in_softirq()); > + may_sleep = (preemptible() && !in_softirq() > + && (system_state >= SYSTEM_RUNNING)); trivial style note: Logic continuations are typically at the end of the previous line. And there are few too many parentheses for my taste. Maybe exceed 80 columns in a single line may_sleep = preemptible() && !in_softirq() && system_state >= SYSTEM_RUNNING; or align the continuation may_sleep = (preemptible() && !in_softirq() && system_state >= SYSTEM_RUNNING); or use individual lines may_sleep = (preemptible() && !in_softirq() && system_state >= SYSTEM_RUNNING);
