On Fri, 2011-06-10 at 14:41 +0200, Peter Zijlstra wrote: > On Fri, 2011-06-10 at 14:34 +0200, Ingo Molnar wrote: > > * Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > > > > thinking that that would have my printk stmts appear on both the > > > fbcon as well as the serial line. But they fail to appear on the > > > latency tracer (current max was 165us waking an idle cpu). > > > > Have you removed this bit: > > > > spin_unlock(&logbuf_lock); > > stop_critical_timings(); /* don't trace print latency */ > > call_console_drivers(_con_start, _log_end); > > start_critical_timings(); > > local_irq_restore(flags); > > > > which hides the latencies from the latency tracer? > > it shouldn't those flags come from spin_lock_irqsave(), which already > has IRQs disabled, so the restore shouldn't re-enable them. > > Hmm,. that might actually already be true for mainline too, yeah, looks > like we call vprintk()->console_unlock() with IRQs-disabled. > > Hohumm.. Also, I used the preemptirqoff tracer, so even if it did re-enable interrupts we should still have preemption disabled and still catch the latency. -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
