Re: [PATCH 0/2] perf jevents: Enable build warnings

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

Em Wed, Oct 20, 2021 at 03:41:01PM +0100, John Garry escreveu:
> On 20/10/2021 15:31, Arnaldo Carvalho de Melo wrote:
> > Em Sat, Oct 16, 2021 at 12:48:25AM +0800, John Garry escreveu:
> > > Currently jevents builds without any complier warning flags enabled. So
> > > use newly-defined HOSTCFLAGS, which comes from EXTRA_WARNINGS. I am not
> > > 100% confident that this is the best way, but sending out for review.
> > > 
> > > Baseline is be8ecc57f180 (HEAD, acme/perf/core) perf srcline: Use
> > > long-running addr2line per DSO
> > 
> > Thanks, applied.
 
> I was going to send a v2, with changes according to James Clark's review  -
> that was to add -Wall & -Werror, but they caused a problem on your perf/core
> branch as they triggered the warn fixed in commit b94729919db2.
 
> I suppose the best thing now is to send a patch on top once perf/core
> contains that commit. Let me know otherwise.

You can send a v2, as:

  29     8.60 debian:experimental-x-mipsel  : FAIL gcc version 11.2.0 (Debian 11.2.0-9)
    util/intel-pt.c: In function 'intel_pt_synth_pebs_sample':
    util/intel-pt.c:2146:33: error: passing argument 1 of 'find_first_bit' from incompatible pointer type [-Werror=incompatible-pointer-types]
     2146 |         for_each_set_bit(hw_id, &items->applicable_counters, INTEL_PT_MAX_PEBS) {
    /git/perf-5.15.0-rc4/tools/include/linux/bitops.h:37:38: note: in definition of macro 'for_each_set_bit'
       37 |         for ((bit) = find_first_bit((addr), (size));            \
          |                                      ^~~~
    In file included from /git/perf-5.15.0-rc4/tools/include/asm-generic/bitops.h:21,
                     from /git/perf-5.15.0-rc4/tools/include/linux/bitops.h:34,
                     from /git/perf-5.15.0-rc4/tools/include/linux/bitmap.h:6,
                     from util/header.h:10,
                     from util/session.h:7,
                     from util/intel-pt.c:16:
    /git/perf-5.15.0-rc4/tools/include/asm-generic/bitops/find.h:109:51: note: expected 'const long unsigned int *' but argument is of type 'const uint64_t *' {aka 'const long long unsigned int *'}

 Adrian, this is on:

 commit 803a3c9233990e1adac8ea2421e3759c2d380cf8
Author: Adrian Hunter <adrian.hunter@intel.com>
Date:   Tue Sep 7 19:39:03 2021 +0300

    perf intel-pt: Add support for PERF_RECORD_AUX_OUTPUT_HW_ID

    Originally, software only supported redirecting at most one PEBS event to
    Intel PT (PEBS-via-PT) because it was not able to differentiate one event
    from another. To overcome that, add support for the
    PERF_RECORD_AUX_OUTPUT_HW_ID side-band event.

    Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
    Reviewed-by: Andi Kleen <ak@linux.intel.com>


That is still just on tmp.perf/core, so we can fix it, probably its just
making that uint64_t into a unsigned long, will check later if you don't
beat me to it.

- Arnaldo