Hi Steve, the following is one for you. The kernel is 2.6.26.1 plus the 2.6.26-rt1 patch (yes it applies against 2.6.26.1) and some of the patches that were discussed in the lists. I don't think it is relevant which patches, but if you need an exact list I will provide it. WARNING: at kernel/trace/trace_hist.c:396 tracing_hist_preempt_stop+0x23d/0x301() Modules linked in: Pid: 1, comm: init Not tainted 2.6.26.1-rt1.jk #4 Call Trace: [<ffffffff802397f4>] warn_on_slowpath+0x5d/0x99 [<ffffffff80212a0d>] ? native_sched_clock+0x2b/0x76 [<ffffffff802127d5>] ? sched_clock+0x9/0xc [<ffffffff80283231>] ? ftrace_now+0x9/0xb [<ffffffff80288439>] ? tracing_hist_preempt_stop+0xd9/0x301 [<ffffffff8020b48c>] ? do_notify_resume+0x14/0x8ef [<ffffffff80286499>] ? trace_hardirqs_on+0x1b/0x138 [<ffffffff8020b48c>] ? do_notify_resume+0x14/0x8ef [<ffffffff8028859d>] tracing_hist_preempt_stop+0x23d/0x301 [<ffffffff8020c4db>] ? sysret_signal+0x30/0x4f [<ffffffff80286499>] trace_hardirqs_on+0x1b/0x138 [<ffffffff8020b478>] ? do_notify_resume+0x0/0x8ef [<ffffffff8020c4db>] ? sysret_signal+0x30/0x4f [<ffffffff8020b4e6>] do_notify_resume+0x6e/0x8ef [<ffffffff8046ce35>] ? rt_spin_lock+0xe/0x10 [<ffffffff8024ea2a>] ? remove_wait_queue+0x3e/0x43 [<ffffffff8023d214>] ? do_wait+0xb6b/0xbf7 [<ffffffff80212a0d>] ? native_sched_clock+0x2b/0x76 [<ffffffff802127d5>] ? sched_clock+0x9/0xc [<ffffffff80283231>] ? ftrace_now+0x9/0xb [<ffffffff80288637>] ? tracing_hist_preempt_stop+0x2d7/0x301 [<ffffffff8020c4b0>] ? sysret_signal+0x5/0x4f [<ffffffff8046ca94>] ? trace_hardirqs_on_thunk+0x3a/0x3c [<ffffffff8020c4db>] ? sysret_signal+0x30/0x4f [<ffffffff8020c8b7>] ptregscall_common+0x67/0xb0 --------------------------- | preempt count: 00000000 ] | 0-level deep critical section nesting: ---------------------------------------- This above is triggered by the WARN_ON in the following code in function tracing_hist_preempt_stop() #if defined(CONFIG_INTERRUPT_OFF_HIST) && defined(CONFIG_PREEMPT_OFF_HIST) if (((!irqs_on && !irqs_disabled()) || (irqs_on && !preempt_count()) || (irqs_on == TRACE_STOP)) && per_cpu(hist_preemptirqsoff_tracing, cpu)) { WARN_ON(!preempt_count() && !irqs_disabled()); if (1 || !stop_set) stop = ftrace_now(cpu); start = per_cpu(hist_preemptirqsoff_start, cpu); latency = (long)nsecs_to_usecs(stop - start); if (latency > 1000000) { printk("%d: latency = %ld (%lu)\n", __LINE__, latency, latency); printk("%d: start=%Ld stop=%Ld\n", __LINE__, start, stop); } barrier(); per_cpu(hist_preemptirqsoff_tracing, cpu) = 0; latency_hist(PREEMPT_INTERRUPT_LATENCY, cpu, latency); } #endif -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html