On 2015/09/24 08:32AM, Stephane Eranian wrote: > On Thu, Sep 24, 2015 at 5:57 AM, Jiri Olsa <[email protected]> wrote: > > > > On Thu, Sep 24, 2015 at 05:41:58PM +0530, Naveen N. Rao wrote: > > > perf build currently fails on powerpc: > > > > > > LINK perf > > > libperf.a(libperf-in.o):(.toc+0x120): undefined reference to > > > `sample_reg_masks' > > > libperf.a(libperf-in.o):(.toc+0x130): undefined reference to > > > `sample_reg_masks' > > > collect2: error: ld returned 1 exit status > > > make[1]: *** [perf] Error 1 > > > make: *** [all] Error 2 > > > > > > This is due to parse-regs-options.c using sample_reg_masks, which is > > > defined only with CONFIG_PERF_REGS. > > > > > > In addition, perf record -I is only useful if the arch supports > > > PERF_REGS. Hence, let's expose -I conditionally. > > > > > > Signed-off-by: Naveen N. Rao <[email protected]> > > > > hum, I wonder why we have sample_reg_masks defined as weak in > > util/perf_regs.c > > which is also built only via CONFIG_PERF_REGS > > > > I wonder we could get rid of the weak definition via attached patch, > > Stephane? > > > But the whole point of having it weak is to avoid this error scenario > on any arch without support > and avoid ugly #ifdef HAVE_ in generic files. > > if perf_regs.c is compiled on PPC, then why do we get the undefined?
As Jiri Olsa pointed out, powerpc and many other architectures don't (yet) have support for perf regs. But, the larger reason to introduce #ifdef is so the user doesn't see options (s)he can't use on a specific architecture, along the same lines as builtin-probe.c Regards, Naveen -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
