Re: [PATCH v2 0/4] Fix perf bench numa, futex and epoll to work with machines having #CPUs > 1K

[Arnaldo Carvalho de Melo]

Em Sat, Apr 09, 2022 at 12:28:01PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Wed, Apr 06, 2022 at 11:21:09PM +0530, Athira Rajeev escreveu:
> > The perf benchmark for collections: numa, futex and epoll
> > hits failure in system configuration with CPU's more than 1024.
> > These benchmarks uses "sched_getaffinity" and "sched_setaffinity"
> > in the code to work with affinity.
> 
> Applied 1-3, 4 needs some reworking and can wait for v5.19, the first 3
> are fixes, so can go now.

Now trying to fix this:

  26     7.89 debian:9                      : FAIL gcc version 6.3.0 20170516 (Debian 6.3.0-18+deb9u1)
    bench/numa.c: In function 'alloc_data':
    bench/numa.c:359:6: error: 'orig_mask' may be used uninitialized in this function [-Werror=maybe-uninitialized]
      ret = sched_setaffinity(0, size, mask);
      ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    bench/numa.c:409:13: note: 'orig_mask' was declared here
      cpu_set_t *orig_mask;
                 ^~~~~~~~~
    cc1: all warnings being treated as errors
    /git/perf-5.18.0-rc1/tools/build/Makefile.build:139: recipe for target 'bench' failed
    make[3]: *** [bench] Error 2


Happened in several distros.

- Arnaldo