hi, Thomas Gleixner, On Wed, Aug 06, 2025 at 12:39:09PM +0200, Thomas Gleixner wrote: > On Wed, Aug 06 2025 at 16:35, Oliver Sang wrote: > > > On Wed, Aug 06, 2025 at 10:19:36AM +0200, Thomas Gleixner wrote: > >> Oliver! > >> > >> On Wed, Aug 06 2025 at 16:01, Oliver Sang wrote: > >> > On Thu, Jul 31, 2025 at 04:03:01PM +0200, Thomas Gleixner wrote: > >> >> On Thu, Jul 31 2025 at 14:34, Thomas Gleixner wrote: > >> >> > Either you make the timeout longer or try the following on the kernel > >> >> > command line instead of 'ftrace_dump_on_cpu': > >> >> > >> >> instead of 'ftrace_dump_ooops' > >> > > >> > sorry for late, I just took several-day off. > >> > >> I hope you had a good time! > >> > >> > attached dmesg FYI. > >> > >> Thanks for doing this. Now the buffer is too short and as nothing stops > >> the tracer the interesting stuff goes out of sight. > >> > >> Can you please apply the patch below and try again? > > > > got it! > > > > just want to confirm, still use below params or need some modification? > > > > trace_event=preemptirq:preempt_disable,preemptirq:preempt_enable ftrace_dump_on_oops=orig_cpu trace_buf_size=100K panic_on_warn=1 > > Those should be good. Let's see. > I applied your patch upon 56180dd20c: * cdf0aafee2bddf test patch for 56180dd20c from Thomas Gleixner * 56180dd20c19e5 futex: Use RCU-based per-CPU reference counting instead of rcuref_t commit cdf0aafee2bddf948281bed5eb0574bf33a09802 Author: 0day robot Date: Wed Aug 6 21:38:42 2025 +0800 test patch for 56180dd20c from Thomas Gleixner diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ec68fc686bd742..2e7d7b5b8e7589 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5900,6 +5900,8 @@ void preempt_count_sub(int val) /* * Underflow? */ + if (val > preempt_count()) + tracing_off(); if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) return; /* attached one dmesg FYI.