Re: [PATCH -next] tracepoint: ipi: don't trace IPI on offline CPUs

From: Sudeep Holla
Date: Wed Mar 09 2016 - 11:40:27 EST

On 09/03/16 16:05, Steven Rostedt wrote:
On Wed, 9 Mar 2016 12:22:22 +0000
Sudeep Holla <sudeep.holla@xxxxxxx> wrote:

Hi Steven,

I observed that in "include/linux/tracepoint.h", we have
#define __DO_TRACE(tp, proto, args, cond, prercu, postrcu)
if (!cpu_online(raw_smp_processor_id()))

if (!(cond))

where !cond check seems reduntant if it's cpu_online check.
So, does this patch handle the warning correctly or is there any better
way ? I did see few traces with same condition, just thought of checking
with you.

Bah, I forgot that we have lockdep checks for when the event isn't

Yes I was about to ask you the same. I did further digging to check if I
was missing something after seeing your series[1] especially patch 2/12
(tracing: Remove duplicate checks for online CPUs)

Can you try this patch:

It works. Thanks for the quick fix.

Tested-by: Sudeep Holla <sudeep.holla@xxxxxxx>