Messages in this thread | | | Date | Tue, 19 May 2015 10:49:51 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH] perf tools: rework of handling lack of sched_getcpu in old glibc |
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Em Tue, May 19, 2015 at 03:20:47PM +0200, Petr Holasek escreveu: > Commit e1e455f4f4d3 ("perf tools: Work around lack of sched_getcpu in > glibc < 2.6.") introduced weak function sched_getcpu() which should > be overridden by sched_getcpu() provided by glibc >= 2.6. Unfortunately, > the weak function was linked to sched_getcpu() used in perf bench numa > and made the benchmark heavily relying on this function unusable. > > This patch alternates weak function magic for preprocessor defines.
With this you break the build again on RHEL5, right? That "fix" was a quickie, the good thing would be to have this sched_getcpu() thing somewhere else, far from its user, i.e. cloexec has no business doing this if there are other places (perf bench numa) that need this, right?
- Arnaldo
> Signed-off-by: Petr Holasek <pholasek@redhat.com> > --- > tools/perf/util/cloexec.c | 13 +++++++++++-- > tools/perf/util/cloexec.h | 6 ------ > 2 files changed, 11 insertions(+), 8 deletions(-) > > diff --git a/tools/perf/util/cloexec.c b/tools/perf/util/cloexec.c > index 85b5238..23b8aa9 100644 > --- a/tools/perf/util/cloexec.c > +++ b/tools/perf/util/cloexec.c > @@ -7,11 +7,20 @@ > > static unsigned long flag = PERF_FLAG_FD_CLOEXEC; > > -int __weak sched_getcpu(void) > +#ifdef __GLIBC_PREREQ > +#if !__GLIBC_PREREQ(2, 6) > +static int do_sched_getcpu(void) > { > errno = ENOSYS; > return -1; > } > +#else > +static int do_sched_getcpu(void) > +{ > + return sched_getcpu(); > +} > +#endif > +#endif > > static int perf_flag_probe(void) > { > @@ -27,7 +36,7 @@ static int perf_flag_probe(void) > pid_t pid = -1; > char sbuf[STRERR_BUFSIZE]; > > - cpu = sched_getcpu(); > + cpu = do_sched_getcpu(); > if (cpu < 0) > cpu = 0; > > diff --git a/tools/perf/util/cloexec.h b/tools/perf/util/cloexec.h > index 68888c2..94a5a7d 100644 > --- a/tools/perf/util/cloexec.h > +++ b/tools/perf/util/cloexec.h > @@ -3,10 +3,4 @@ > > unsigned long perf_event_open_cloexec_flag(void); > > -#ifdef __GLIBC_PREREQ > -#if !__GLIBC_PREREQ(2, 6) > -extern int sched_getcpu(void) __THROW; > -#endif > -#endif > - > #endif /* __PERF_CLOEXEC_H */ > -- > 2.1.0
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