Re: [PATCH 0/2 v2] [GIT PULL][v3.2] tracing: queued updates

[Steven Rostedt <rostedt@goodmis.org>]

[ Added Peter Zijlstra ]

On Thu, 2011-10-13 at 10:59 +0200, Ingo Molnar wrote:
> * Ingo Molnar <mingo@elte.hu> wrote:
> 
> > Tests are also looking good so far.
> 
> there's a cross-build failure on the m32r architecture:

Hmm, I don't have a m32r cross compiler in my arsenal.

 
> 
> /home/mingo/tip/kernel/trace/trace_clock.c:117: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'trace_counter'
> /home/mingo/tip/kernel/trace/trace_clock.c: In function 'trace_clock_counter':
> /home/mingo/tip/kernel/trace/trace_clock.c:126: error: implicit declaration of function 'atomic64_add_return'
> /home/mingo/tip/kernel/trace/trace_clock.c:126: error: 'trace_counter' undeclared (first use in this function)
> /home/mingo/tip/kernel/trace/trace_clock.c:126: error: (Each undeclared identifier is reported only once
> /home/mingo/tip/kernel/trace/trace_clock.c:126: error: for each function it appears in.)

At that line there's:

static atomic64_t trace_counter;

I take it that m32r does not define an atomic64_t. Does this mean that
we can not use it? This code was taken from Peter, as it stated in the
commit log:

commit 6249687f76b69cc0b2ad34636f4a18d693ef3262
tracing: Add a counter clock for those that do not trust clocks

[...]

    The trace_clock_counter() is added from the attempt by Peter Zijlstra
    trying to convert the trace_clock_global() to it. I took Peter's counter
    code and made trace_clock_counter() instead, and added it to the choice
    of clocks. Just echo counter > /debug/tracing/trace_clock to activate
    it.

I think the fix to this is to add:

CONFIG_GENERIC_ATOMIC64 to m32r.

-- Steve