| Message ID | 20200623123141.27747-2-liwei391@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | perf tools: Fix record failure when mixed with ARM SPE event | expand |
On Tue, Jun 23, 2020 at 08:31:40PM +0800, Wei Li wrote: > Remove the useless check code to make it clear. > > Signed-off-by: Wei Li <liwei391@huawei.com> > --- > tools/perf/arch/arm/util/auxtrace.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/tools/perf/arch/arm/util/auxtrace.c b/tools/perf/arch/arm/util/auxtrace.c > index 0a6e75b8777a..62b7b03d691a 100644 > --- a/tools/perf/arch/arm/util/auxtrace.c > +++ b/tools/perf/arch/arm/util/auxtrace.c > @@ -57,7 +57,7 @@ struct auxtrace_record > struct evsel *evsel; > bool found_etm = false; > bool found_spe = false; > - static struct perf_pmu **arm_spe_pmus = NULL; > + static struct perf_pmu **arm_spe_pmus; > static int nr_spes = 0; > int i = 0; > > @@ -65,9 +65,7 @@ struct auxtrace_record > return NULL; > > cs_etm_pmu = perf_pmu__find(CORESIGHT_ETM_PMU_NAME); > - > - if (!arm_spe_pmus) > - arm_spe_pmus = find_all_arm_spe_pmus(&nr_spes, err); > + arm_spe_pmus = find_all_arm_spe_pmus(&nr_spes, err); Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> > > evlist__for_each_entry(evlist, evsel) { > if (cs_etm_pmu && > -- > 2.17.1 >
Hi Wei, On Tue, Jun 23, 2020 at 08:31:40PM +0800, Wei Li wrote: > Remove the useless check code to make it clear. > > Signed-off-by: Wei Li <liwei391@huawei.com> > --- > tools/perf/arch/arm/util/auxtrace.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/tools/perf/arch/arm/util/auxtrace.c b/tools/perf/arch/arm/util/auxtrace.c > index 0a6e75b8777a..62b7b03d691a 100644 > --- a/tools/perf/arch/arm/util/auxtrace.c > +++ b/tools/perf/arch/arm/util/auxtrace.c > @@ -57,7 +57,7 @@ struct auxtrace_record > struct evsel *evsel; > bool found_etm = false; > bool found_spe = false; > - static struct perf_pmu **arm_spe_pmus = NULL; > + static struct perf_pmu **arm_spe_pmus; Here the 'static' should be removed as well. Just for more complete background info, IIUC, at the beginning to enable SPE's PMU event, since SPE is micro-architecture dependent (though it's defined in ARMv8-ARM, but it might be different for different ARM micro-architectures). So this is why here it uses 'static' for varaible "arm_spe_pmus", it wants to initialize the variable with finding all SPE PMU structure at the first time when invoke the function auxtrace_record__init(), and afterwards we can reuse the variable "arm_spe_pmus" and without calling find_all_arm_spe_pmus() anymore. So I struggled to figure out what's good thing to do with multiple SPE PMU events, and your change is good thing to me. The reason is: - Firstly, the function auxtrace_record__init() will be invoked only once, the variable "arm_spe_pmus" will not be used afterwards, thus we don't need to check "arm_spe_pmus" is NULL or not; - Another reason is, even though SPE is micro-architecture dependent, but so far it only supports "statistical-profiling-extension-v1" and we have no chance to use multiple SPE's PMU events in Perf command. So after removing 'static' for varaible "arm_spe_pmus": Reviewed-by: Leo Yan <leo.yan@linaro.org> P.s. Sorry if it's my reason that James Clark's patch [1] has not been merged in the mainline kernel and introduced duplicate efforts at here. James's patch used similiar method to resolve this same issue. [1] https://lkml.org/lkml/2019/12/20/293 > static int nr_spes = 0; > int i = 0; > > @@ -65,9 +65,7 @@ struct auxtrace_record > return NULL; > > cs_etm_pmu = perf_pmu__find(CORESIGHT_ETM_PMU_NAME); > - > - if (!arm_spe_pmus) > - arm_spe_pmus = find_all_arm_spe_pmus(&nr_spes, err); > + arm_spe_pmus = find_all_arm_spe_pmus(&nr_spes, err); > > evlist__for_each_entry(evlist, evsel) { > if (cs_etm_pmu && > -- > 2.17.1 >
diff --git a/tools/perf/arch/arm/util/auxtrace.c b/tools/perf/arch/arm/util/auxtrace.c index 0a6e75b8777a..62b7b03d691a 100644 --- a/tools/perf/arch/arm/util/auxtrace.c +++ b/tools/perf/arch/arm/util/auxtrace.c @@ -57,7 +57,7 @@ struct auxtrace_record struct evsel *evsel; bool found_etm = false; bool found_spe = false; - static struct perf_pmu **arm_spe_pmus = NULL; + static struct perf_pmu **arm_spe_pmus; static int nr_spes = 0; int i = 0; @@ -65,9 +65,7 @@ struct auxtrace_record return NULL; cs_etm_pmu = perf_pmu__find(CORESIGHT_ETM_PMU_NAME); - - if (!arm_spe_pmus) - arm_spe_pmus = find_all_arm_spe_pmus(&nr_spes, err); + arm_spe_pmus = find_all_arm_spe_pmus(&nr_spes, err); evlist__for_each_entry(evlist, evsel) { if (cs_etm_pmu &&
Remove the useless check code to make it clear. Signed-off-by: Wei Li <liwei391@huawei.com> --- tools/perf/arch/arm/util/auxtrace.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)