Subject: Re: linux-next: tracing tree build failure

From: Ingo Molnar <[email-masked]>
Date: Tue, 10 Mar 2009 10:10:10 +0100

* Tejun Heo <[email-masked]> wrote:

> Stephen Rothwell wrote:
> > Hi all,
> > 
> > Today's linux-next build (x86_64 allmodconfig) failed like this:
> > 
> > kernel/trace/trace_functions_graph.c: In function 'graph_trace_close':
> > kernel/trace/trace_functions_graph.c:836: error: implicit declaration of function 'percpu_free'
> > 
> > The direct cause is commit 422d3c7a577b15e1384c9d4e72a9540896b685fa
> > ("tracing: current tip/master can't enable ftrace") from the tracing tree
> > which exposed an interaction between commit
> > f2a8205c4ef1af917d175c36a4097ae5587791c8 ("percpu: kill percpu_alloc()
> > and friends") from the tip-core tree and commit
> > 9005f3ebebfcfe9ccd731d16c468907a35ac1f9a ("tracing/function-graph-tracer:
> > various fixes and features") from the tracing tree.
> > 
> > I have reverted commit 422d3c7a577b15e1384c9d4e72a9540896b685fa for
> > today.  (As a side note, that commit has no Signed-off-by ...)
> 
> Just in case someone doesn't know yet.  The remedy is using
> free_percpu() instead of percpu_free().

That's exactly how it was resolved more than two weeks ago in 
tip:master - and has been resolved in tip:master since then.

I'm glad to hear about new bugs, but the amount of false 
positives from linux-next is wasting a lot of time - the 
duplication rate is above 90% which is way too much.

tip:master is a full, well-tested integration of all those 
branches. It would be nice if Stephen investigated tip:master 
before reporting such solved-long-ago interactions.

	Ingo