On Tue, 12 Sep 2017 20:18:35 +0800 "Ziqian SUN (Zamir)" <z...@redhat.com> wrote:
> >> I feel the core trace printed by WARN is not so meaningful, so I use > >> pr_warn instead. > > > > I'm fine with pr_warn, but I'm curious to what you mean by "not so > > meaningful"? A WARN() will cause a dump stack, which usually shows up > > as a bug in systems and more likely to be seen. But if someone is > > adding this to the kernel command line and it's not working, they > > should be looking for the tracer name within the dmesg anyway. > > > > Following is the log I tried with WARN before. With WARN we have both > the warning message, and the stack trace. The stack trace goes into > stacing_set_tracer, but not showing mmiotrace. I mean, this is useful > for debugging, but maybe confusing for users who is willing to report > bugs but not a kernel geek. With pr_warn we already indicate mmiotrace > is ignored, and is neat. > I'm now leaning towards WARN() over pr_warn(). Sure it's more useful for a kernel geek and not an everyday user, but I will counter that an everyday user should most definitely not be enabling mmiotrace! Or other traces for that matter. But then again, it's not really a bug (it's a feature), so I guess I'll just take this patch as is. -- Steve
