Re: pagefaults and hang with 5.15.11

[John David Anglin <dave.anglin@xxxxxxxx>]

On 2021-12-26 11:21 a.m., Rolf Eike Beer wrote:
> [139181.966881] WARNING: CPU: 1 PID: 0 at kernel/rcu/tree.c:613 rcu_eqs_enter.constprop.0+0x8c/0x98
This is probably not reproducible. You might try this change from Sven

diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index cf92ece20b75..0cd97fa004c5 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -228,11 +228,13 @@ static inline void
 send_IPI_allbutself(enum ipi_message_type op)
 {
        int i;
-
+
+       preempt_disable();
        for_each_online_cpu(i) {
                if (i != smp_processor_id())
                        send_IPI_single(i, op);
        }
+       preempt_enable();
 }

 #ifdef CONFIG_KGDB

and my "[PATCH v3] parisc: Rewrite light-weight syscall and futex code" change. Page faults in the LWS code
can mess up scheduling.

I haven't found 5.15.11 to be stable.

Dave

--
John David Anglin  dave.anglin@xxxxxxxx