----- Original Message ----- > From: "Steven Rostedt" <[email protected]> > To: "Mathieu Desnoyers" <[email protected]> > Cc: "LKML" <[email protected]>, "Andrew Morton" > <[email protected]>, "Javi Merino" > <[email protected]>, "David Howells" <[email protected]>, "Ingo Molnar" > <[email protected]> > Sent: Tuesday, May 6, 2014 5:06:40 PM > Subject: Re: [RFA][PATCH] tracing: Add trace_<tracepoint>_enabled() function > > On Tue, 6 May 2014 20:53:41 +0000 (UTC) > Mathieu Desnoyers <[email protected]> wrote: > [...] > > > > The first time I thought about using this was with David's code, which > > > does this: > > > > > > if (static_key_false(&i2c_trace_msg)) { > > > int i; > > > for (i = 0; i < ret; i++) > > > if (msgs[i].flags & I2C_M_RD) > > > trace_i2c_reply(adap, &msgs[i], i); > > > trace_i2c_result(adap, i, ret); > > > } > > > > > > That would look rather silly in a tracepoint. > > > > Which goes with a mandatory silly question: how do you intend mapping > > the single key to two different tracepoints ? > > Could always do: > > if (trace_i2c_result_enabled() || trace_i2c_reply_enabled()) { > > I wounder what the assembly of that would look like.
I would expect it to generate two static jump sites back to back. > > Still, having "side-effects" in the tracepoint parameters just seems > odd to me. I agree that the "enabled" static inline approach is more flexible. So if we document it well enough, it might be OK in the end. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
