Messages in this thread | | | Subject | Re: [PATCH] tracing: add trace console | From | Johannes Berg <> | Date | Wed, 16 Nov 2011 19:33:00 +0100 |
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On Wed, 2011-11-16 at 12:00 -0500, Steven Rostedt wrote: > On Wed, 2011-11-16 at 17:45 +0100, Johannes Berg wrote: > > > I briefly looked at it just after writing the email, but quickly got > > lost in printk.c because of the multi-line handling it has. We could > > instead trace each call to printk(), so the multi-line stuff would end > > up in multiple events, but all of that code is too much vodoo for me :) > > Here's what can go into printk.c: > > diff --git a/kernel/printk.c b/kernel/printk.c > index 1455a0d..4b8445a 100644 > --- a/kernel/printk.c > +++ b/kernel/printk.c > @@ -542,6 +542,7 @@ MODULE_PARM_DESC(ignore_loglevel, "ignore loglevel setting, to" > static void _call_console_drivers(unsigned start, > unsigned end, int msg_log_level) > { > + trace_console(&LOG_BUF(start), end - start); > if ((msg_log_level < console_loglevel || ignore_loglevel) && > console_drivers && start != end) { > if ((start & LOG_BUF_MASK) > (end & LOG_BUF_MASK)) { > > > And then you can make a TRACE_EVENT(console) that takes a buffer and a > len, and write that to the ring buffer.
Yes, of course, but if we're going to modify the code then I thought we should probably trace everything independent of the console printk level.
johannes
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