Message-ID: <1337368492.7562.8.camel@gandalf.stny.rr.com>
Subject: Re: [PATCH] power, trace: add tracing for device_resume
From: Steven Rostedt <rostedt@goodmis.org>
To: Sameer Nanda <snanda@chromium.org>
Cc: Greg KH <gregkh@linuxfoundation.org>, rob@landley.net, len.brown@intel.com,
        pavel@ucw.cz, rjw@sisk.pl, fweisbec@gmail.com, mingo@redhat.com,
        jkosina@suse.cz, standby24x7@gmail.com, jj@chaosbits.net,
        paulmck@linux.vnet.ibm.com, josh@joshtriplett.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-pm@vger.kernel.org
Date: Fri, 18 May 2012 15:14:52 -0400
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	 <20120518183756.GA3216@kroah.com>
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On Fri, 2012-05-18 at 11:57 -0700, Sameer Nanda wrote:

> AFAICT, they are used for something completely different -- help solve
> suspend/resume issues by saving a hash in the RTC of the last device
> that suspended/resumed.  They don't use the perf tracing mechanism at
> all.
> 

Also note that all tracepoints have timestamps attached to them. You do
not need to add deltas. Do that in the userspace tools that read the
timestamps and events. This way you can have one DECLARE_EVENT_CLASS and
three DEFINE_EVENTs. This will save space.

-- Steve


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