Re: [PATCH 1/2] tracing: show size of requested buffer

From: Steven Rostedt
Date: Tue Oct 26 2021 - 16:43:59 EST


On Thu, 7 Oct 2021 09:23:58 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> On Thu, 7 Oct 2021 09:11:51 +0200
> Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> > > > +++ b/kernel/trace/trace_event_perf.c
> > > > @@ -400,7 +400,8 @@ void *perf_trace_buf_alloc(int size, struct pt_regs **regs, int *rctxp)
> > > > BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(unsigned long));
> > > >
> > > > if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
> > > > - "perf buffer not large enough"))
> > > > + "perf buffer not large enough, wanted %d, have %d",
> > > > + size, PERF_MAX_TRACE_SIZE))
> >
> > Priting a constant seems daft.. why is any of this important in any way?
>
> I see your point, but it can be useful if you changed it, and want to know
> if you are running the kernel with the change or not.
>
> I've done daft things were I changed a const and was running a kernel
> without the change and couldn't understand why it wasn't working ;-)

Peter,

Do you have any real issue if I just take this patch set through my tree?

-- Steve