Anshuman Khandual <khand...@linux.vnet.ibm.com> wrote: > On 06/06/2013 10:26 AM, Michael Neuling wrote: > > Anshuman Khandual <khand...@linux.vnet.ibm.com> wrote: > > > >> Completely ignore BHRB privilege state filter request as we are > >> already configuring that with privilege state filtering attribute > >> for the accompanying PMU event. This would help achieve cleaner > >> user space interaction for BHRB. > >> > >> This patch fixes a situation like this > >> > >> Before patch:- > >> ------------ > >> ./perf record -j any -e branch-misses:k ls > >> Error: > >> The sys_perf_event_open() syscall returned with 95 (Operation not > >> supported) for event (branch-misses:k). > >> /bin/dmesg may provide additional information. > >> No CONFIG_PERF_EVENTS=y kernel support configured? > >> > >> Here 'perf record' actually copies over ':k' filter request into BHRB > >> privilege state filter config and our previous check in kernel would > >> fail that. > >> > >> After patch:- > >> ------------- > >> ./perf record -j any -e branch-misses:k ls > >> perf perf.data perf.data.old test-mmap-ring > >> [ perf record: Woken up 1 times to write data ] > >> [ perf record: Captured and wrote 0.002 MB perf.data (~102 samples) ] > >> > >> Signed-off-by: Anshuman Khandual <khand...@linux.vnet.ibm.com> > >> --- > >> arch/powerpc/perf/power8-pmu.c | 12 ++++-------- > >> 1 file changed, 4 insertions(+), 8 deletions(-) > >> > >> diff --git a/arch/powerpc/perf/power8-pmu.c > >> b/arch/powerpc/perf/power8-pmu.c > >> index f7d1c4f..3a58416 100644 > >> --- a/arch/powerpc/perf/power8-pmu.c > >> +++ b/arch/powerpc/perf/power8-pmu.c > >> @@ -525,16 +525,12 @@ static u64 power8_bhrb_filter_map(u64 > >> branch_sample_type) > >> u64 pmu_bhrb_filter = 0; > >> u64 br_privilege = branch_sample_type & ONLY_PLM; > >> > >> - /* BHRB and regular PMU events share the same prvillege state > >> + /* BHRB and regular PMU events share the same privilege state > >> * filter configuration. BHRB is always recorded along with a > >> - * regular PMU event. So privilege state filter criteria for BHRB > >> - * and the companion PMU events has to be the same. As a default > >> - * "perf record" tool sets all privillege bits ON when no filter > >> - * criteria is provided in the command line. So as along as all > >> - * privillege bits are ON or they are OFF, we are good to go. > >> + * regular PMU event. As the privilege state filter is handled > >> + * in the basic PMC configuration of the accompanying regular > >> + * PMU event, we ignore any separate BHRB specific request. > >> */ > >> - if ((br_privilege != 7) && (br_privilege != 0)) > >> - return -1; > > > > br_privilege is now unused which causes this compile error. > > > > arch/powerpc/perf/power8-pmu.c:526:6: error: unused variable ‘br_privilege’ > > [-Werror=unused-variable] > > > > I assume since you didn't compile test this code, you also didn't > > runtime test it either?!!?!?!? > > > Always compile with the cross compiler "ARCH=powerpc > CROSS_COMPILE=powerpc64-linux-gnu- make" I copied over > arch/powerpc/config/pseries_defconfig and compiled it. Some how it > missed to be a 64 bit kernel config which resulted in shutting down > compilation of arch/powerpc/perf/power8-pmu.c file. So never > encountered this compiler warning message before. Will fix this.
I don't understand this at all... pseries_defconfig is a 64bit kernel. BTW. you don't need to copy it. Just do "make pseries_defconfig && make vmlinux". Mikey _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
