Messages in this thread | | | Subject | Re: [PATCH 1/3] printk: Release console_sem after logbuf_lock | From | Peter Zijlstra <> | Date | Fri, 10 Jun 2011 14:41:54 +0200 |
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On Fri, 2011-06-10 at 14:34 +0200, Ingo Molnar wrote: > * Peter Zijlstra <peterz@infradead.org> 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..
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