| Message ID | 20210412091006.468557-2-leo.yan@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | perf arm-spe: Enable timestamp | expand |
On 12/04/2021 12:10, Leo Yan wrote: > The enum value 'ARM_SPE_PER_CPU_MMAPS' is never used so remove it. Hi Leo, I think this causes an error when attempting to open a newly recorded file with an old version of perf. The value ARM_SPE_AUXTRACE_PRIV_MAX is used here: size_t min_sz = sizeof(u64) * ARM_SPE_AUXTRACE_PRIV_MAX; struct perf_record_time_conv *tc = &session->time_conv; struct arm_spe *spe; int err; if (auxtrace_info->header.size < sizeof(struct perf_record_auxtrace_info) + min_sz) return -EINVAL; And removing ARM_SPE_PER_CPU_MMAPS changes the value of ARM_SPE_AUXTRACE_PRIV_MAX. At least I think that's what's causing the problem. I get this error: ./perf report -i per-thread-spe-time.data 0x1c0 [0x18]: failed to process type: 70 [Invalid argument] Error: failed to process sample # To display the perf.data header info, please use --header/--header-only options. # James > > Signed-off-by: Leo Yan <leo.yan@linaro.org> > --- > tools/perf/util/arm-spe.h | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/tools/perf/util/arm-spe.h b/tools/perf/util/arm-spe.h > index 98d3235781c3..105ce0ea0a01 100644 > --- a/tools/perf/util/arm-spe.h > +++ b/tools/perf/util/arm-spe.h > @@ -11,7 +11,6 @@ > > enum { > ARM_SPE_PMU_TYPE, > - ARM_SPE_PER_CPU_MMAPS, > ARM_SPE_AUXTRACE_PRIV_MAX, > }; > >
Hi James, On Thu, Apr 15, 2021 at 05:13:36PM +0300, James Clark wrote: > On 12/04/2021 12:10, Leo Yan wrote: > > The enum value 'ARM_SPE_PER_CPU_MMAPS' is never used so remove it. > > Hi Leo, > > I think this causes an error when attempting to open a newly recorded file > with an old version of perf. The value ARM_SPE_AUXTRACE_PRIV_MAX is used here: > > size_t min_sz = sizeof(u64) * ARM_SPE_AUXTRACE_PRIV_MAX; > struct perf_record_time_conv *tc = &session->time_conv; > struct arm_spe *spe; > int err; > > if (auxtrace_info->header.size < sizeof(struct perf_record_auxtrace_info) + > min_sz) > return -EINVAL; > > And removing ARM_SPE_PER_CPU_MMAPS changes the value of ARM_SPE_AUXTRACE_PRIV_MAX. > > At least I think that's what's causing the problem. I get this error: > > ./perf report -i per-thread-spe-time.data > 0x1c0 [0x18]: failed to process type: 70 [Invalid argument] > Error: > failed to process sample > # To display the perf.data header info, please use --header/--header-only options. > # Yes, when working on this patch I had concern as well. I carefully thought that the perf tool should be backwards-compatible, but there have no requirement for forwards-compatibility. This is the main reason why I kept this patch. If you or anyone could confirm the forwards-compatibility is required, it's quite fine for me to drop this patch. Thanks a lot for the reviewing and testing! Leo
On 15/04/2021 17:41, Leo Yan wrote: > Hi James, > > On Thu, Apr 15, 2021 at 05:13:36PM +0300, James Clark wrote: >> On 12/04/2021 12:10, Leo Yan wrote: >>> The enum value 'ARM_SPE_PER_CPU_MMAPS' is never used so remove it. >> >> Hi Leo, >> >> I think this causes an error when attempting to open a newly recorded file >> with an old version of perf. The value ARM_SPE_AUXTRACE_PRIV_MAX is used here: >> >> size_t min_sz = sizeof(u64) * ARM_SPE_AUXTRACE_PRIV_MAX; >> struct perf_record_time_conv *tc = &session->time_conv; >> struct arm_spe *spe; >> int err; >> >> if (auxtrace_info->header.size < sizeof(struct perf_record_auxtrace_info) + >> min_sz) >> return -EINVAL; >> >> And removing ARM_SPE_PER_CPU_MMAPS changes the value of ARM_SPE_AUXTRACE_PRIV_MAX. >> >> At least I think that's what's causing the problem. I get this error: >> >> ./perf report -i per-thread-spe-time.data >> 0x1c0 [0x18]: failed to process type: 70 [Invalid argument] >> Error: >> failed to process sample >> # To display the perf.data header info, please use --header/--header-only options. >> # > > Yes, when working on this patch I had concern as well. > > I carefully thought that the perf tool should be backwards-compatible, > but there have no requirement for forwards-compatibility. This is the > main reason why I kept this patch. > > If you or anyone could confirm the forwards-compatibility is required, > it's quite fine for me to drop this patch. > Personally, I can easily imagine sending a file to someone to open with an older version and it causing friction where it could be easily avoided. And it even made testing a bit more difficult because I wanted to compare opening the same file with the patched and un-patched version. But if there is no hard requirement I can't really put too much pressure to not remove it. > Thanks a lot for the reviewing and testing! > Leo >
diff --git a/tools/perf/util/arm-spe.h b/tools/perf/util/arm-spe.h index 98d3235781c3..105ce0ea0a01 100644 --- a/tools/perf/util/arm-spe.h +++ b/tools/perf/util/arm-spe.h @@ -11,7 +11,6 @@ enum { ARM_SPE_PMU_TYPE, - ARM_SPE_PER_CPU_MMAPS, ARM_SPE_AUXTRACE_PRIV_MAX, };
The enum value 'ARM_SPE_PER_CPU_MMAPS' is never used so remove it. Signed-off-by: Leo Yan <leo.yan@linaro.org> --- tools/perf/util/arm-spe.h | 1 - 1 file changed, 1 deletion(-)