----- Original Message ----- > From: "Steven Rostedt" <[email protected]> > To: "Mathieu Desnoyers" <[email protected]> > Cc: [email protected], "Linus Torvalds" > <[email protected]>, "Ingo Molnar" <[email protected]>, > "Andrew Morton" <[email protected]>, "Thomas Gleixner" > <[email protected]>, "Paul E. McKenney" > <[email protected]> > Sent: Sunday, December 14, 2014 12:21:36 PM > Subject: Re: [PATCH 1/3] tracepoints: Do not use call_rcu_sched() before > early_initcall() > > On Sun, 14 Dec 2014 12:14:57 -0500 > Steven Rostedt <[email protected]> wrote: > > > If IRQ setup, or other core pieces of code can use this, then I would > > agree that rcu should be changed. But until then, I rather not add > > another conditional to the core RCU code. > > Also, call_rcu*() is called from several hot paths. This location is > not a hot path, and actually, it is in fact rather slow. That's another > reason not to add the logic into the RCU code if just adding it to > tracepoints is sufficient.
Given that your reason for having this RCU-specific logic in tracepoint.c rather than within call_rcu*() is not slowing down a fast-path, how about creating a new call_rcu_early() and call_rcu_sched_early() which can be called in normal operation and at early boot ? This would allow us to keep the RCU logic within the RCU implementation rather than strongly coupling it with the tracepoint code. 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/
