Re: [was: libtraceevent: Increase libtraceevent logging when verbose]

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Mon, Jan 03, 2022 at 09:25:26AM +0100, Jiri Slaby escreveu:
> Ping -- perf build is still broken in 5.16-rc8 due to this.
> 
> On 16. 12. 21, 9:07, Jiri Slaby wrote:
> > Hi,
> > 
> > On 23. 09. 21, 2:10, Ian Rogers wrote:
> > > libtraceevent has added more levels of debug printout and with changes
> > > like:
> > > https://lore.kernel.org/linux-trace-devel/20210507095022.1079364-3-tz.stoyanov@gmail.com
> > > 
> > > previously generated output like "registering plugin" is no longer
> > > displayed. This change makes it so that if perf's verbose debug output
> > > is enabled then the debug and info libtraceevent messages can be
> > > displayed.
> > > The code is conditionally enabled based on the libtraceevent version as
> > > discussed in the RFC:
> > > https://lore.kernel.org/lkml/20210610060643.595673-1-irogers@google.com/
> > > 
> > > v2. Is a rebase and handles the case of building without
> > >      LIBTRACEEVENT_DYNAMIC.
> > 
> > It breaks build with LIBTRACEEVENT_DYNAMIC and version 1.3.0:
> >  > util/debug.c: In function ‘perf_debug_option’:
> >  > util/debug.c:243:17: error: implicit declaration of function
> > ‘tep_set_loglevel’ [-Werror=implicit-function-declaration]
> >  >   243 |                 tep_set_loglevel(TEP_LOG_INFO);
> >  >       |                 ^~~~~~~~~~~~~~~~
> >  > util/debug.c:243:34: error: ‘TEP_LOG_INFO’ undeclared (first use in
> > this function); did you mean ‘TEP_PRINT_INFO’?
> >  >   243 |                 tep_set_loglevel(TEP_LOG_INFO);
> >  >       |                                  ^~~~~~~~~~~~
> >  >       |                                  TEP_PRINT_INFO
> >  > util/debug.c:243:34: note: each undeclared identifier is reported
> > only once for each function it appears in
> >  > util/debug.c:245:34: error: ‘TEP_LOG_DEBUG’ undeclared (first use in
> > this function)
> >  >   245 |                 tep_set_loglevel(TEP_LOG_DEBUG);
> >  >       |                                  ^~~~~~~~~~~~~
> >  > util/debug.c:247:34: error: ‘TEP_LOG_ALL’ undeclared (first use in
> > this function)
> >  >   247 |                 tep_set_loglevel(TEP_LOG_ALL);
> >  >       |                                  ^~~~~~~~~~~
> > 
> > It is because the gcc's command line looks like:
> > gcc
> > ...
> > -I/home/abuild/rpmbuild/BUILD/tools/lib/
> > ...
> > -DLIBTRACEEVENT_VERSION=65790
> > ...
> > 
> > So:
> > 
> > 
> > > --- a/tools/perf/util/debug.c
> > > +++ b/tools/perf/util/debug.c
> > > @@ -24,6 +24,16 @@
> > >   #include "util/parse-sublevel-options.h"
> > >   #include <linux/ctype.h>
> > > +#include <traceevent/event-parse.h>
> > 
> > /home/abuild/rpmbuild/BUILD/tools/lib/traceevent/event-parse.h is taken
> > here.
> > 
> > > @@ -228,6 +238,15 @@ int perf_debug_option(const char *str)
> > >       /* Allow only verbose value in range (0, 10), otherwise set 0. */
> > >       verbose = (verbose < 0) || (verbose > 10) ? 0 : verbose;
> > > +#if MAKE_LIBTRACEEVENT_VERSION(1, 3, 0) <= LIBTRACEEVENT_VERSION
> > 
> > But
> > -DLIBTRACEEVENT_VERSION=65790
> > is taken here (which is 1.3.0).
> > 
> > > +    if (verbose == 1)
> > > +        tep_set_loglevel(TEP_LOG_INFO);
> > > +    else if (verbose == 2)
> > > +        tep_set_loglevel(TEP_LOG_DEBUG);
> > > +    else if (verbose >= 3)
> > > +        tep_set_loglevel(TEP_LOG_ALL);
> > > +#endif
> > > +
> > >       return 0;
> > >   }

Tried reproducing here on fedora 34 but it is at 1.1.1:

make: Leaving directory '/var/home/acme/git/perf/tools/perf'

 Performance counter stats for 'make -k LIBTRACEEVENT_DYNAMIC=1 BUILD_BPF_SKEL=1 CORESIGHT=1 PYTHON=python3 O=/tmp/build/perf -C tools/perf install-bin':

   397,176,418,790      cycles:u                                                    
   493,885,896,752      instructions:u            #    1.24  insn per cycle         

       8.664957770 seconds time elapsed

      97.706894000 seconds user
      23.714293000 seconds sys


On branch perf/urgent
Your branch is ahead of 'quaco/perf/urgent' by 369 commits.
  (use "git push" to publish your local commits)

nothing to commit, working tree clean
19: 'import perf' in python                                         : Ok
⬢[acme@toolbox perf]$ git diff
⬢[acme@toolbox perf]$ rpm -q libtraceevent-devel
libtraceevent-devel-1.1.1-2.fc34.x86_64

Lemme see in a container so that I can also test the fix.

- Arnaldo