| Message ID | 20210807005807.1083943-2-valentin.schneider@arm.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | rcu, arm64: PREEMPT_RT fixlets | expand |
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index eecd1caef71d..4f3db1d3170d 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1548,6 +1548,8 @@ rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp) * them on non-RT. */ if (IS_ENABLED(CONFIG_PREEMPT_RT)) { + /* Can't disable bh in atomic context under PREEMPT_RT */ + mask &= ~(RCUTORTURE_RDR_ATOM_BH | RCUTORTURE_RDR_ATOM_RBH); /* * Can't release the outermost rcu lock in an irq disabled * section without preemption also being disabled, if irqs
Running RCU torture with CONFIG_PREEMPT_RT under v5.14-rc4-rt6 triggers: [ 8.755472] DEBUG_LOCKS_WARN_ON(this_cpu_read(softirq_ctrl.cnt)) [ 8.755482] WARNING: CPU: 1 PID: 137 at kernel/softirq.c:172 __local_bh_disable_ip (kernel/softirq.c:172 (discriminator 31)) [ 8.755500] Modules linked in: [ 8.755506] CPU: 1 PID: 137 Comm: rcu_torture_rea Not tainted 5.14.0-rc4-rt6 #171 [ 8.755514] Hardware name: ARM Juno development board (r0) (DT) [ 8.755518] pstate: 60000005 (nZCv daif -PAN -UAO -TCO BTYPE=--) [ 8.755622] Call trace: [ 8.755624] __local_bh_disable_ip (kernel/softirq.c:172 (discriminator 31)) [ 8.755633] rcutorture_one_extend (kernel/rcu/rcutorture.c:1453) [ 8.755640] rcu_torture_one_read (kernel/rcu/rcutorture.c:1601 kernel/rcu/rcutorture.c:1645) [ 8.755645] rcu_torture_reader (kernel/rcu/rcutorture.c:1737) [ 8.755650] kthread (kernel/kthread.c:327) [ 8.755656] ret_from_fork (arch/arm64/kernel/entry.S:783) [ 8.755663] irq event stamp: 11959 [ 8.755666] hardirqs last enabled at (11959): __rcu_read_unlock (kernel/rcu/tree_plugin.h:695 kernel/rcu/tree_plugin.h:451) [ 8.755675] hardirqs last disabled at (11958): __rcu_read_unlock (kernel/rcu/tree_plugin.h:661 kernel/rcu/tree_plugin.h:451) [ 8.755683] softirqs last enabled at (11950): __local_bh_enable_ip (./arch/arm64/include/asm/irqflags.h:85 kernel/softirq.c:261) [ 8.755692] softirqs last disabled at (11942): rcutorture_one_extend (./include/linux/bottom_half.h:19 kernel/rcu/rcutorture.c:1441) Per this warning, softirqs cannot be disabled in a non-preemptible region under CONFIG_PREEMPT_RT. Adjust RCU torture accordingly. Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> --- kernel/rcu/rcutorture.c | 2 ++ 1 file changed, 2 insertions(+)