| Message ID | 20220922033349.2908447-1-namhyung@kernel.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | BPF |
| Headers | show |
| Series | perf stat: Get a perf cgroup more portably in BPF | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
On Wed, Sep 21, 2022 at 8:33 PM Namhyung Kim <namhyung@kernel.org> wrote: > > The perf_event_cgrp_id can be different on other configurations. > To be more portable as CO-RE, it needs to get the cgroup subsys id > using the bpf_core_enum_value() helper. > > Suggested-by: Ian Rogers <irogers@google.com> > Signed-off-by: Namhyung Kim <namhyung@kernel.org> > --- > tools/perf/util/bpf_skel/bperf_cgroup.bpf.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c b/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c > index c72f8ad96f75..35a8e38d3ee3 100644 > --- a/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c > +++ b/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c > @@ -57,8 +57,10 @@ static inline int get_cgroup_v1_idx(__u32 *cgrps, int size) > __u32 *elem; > int level; > int cnt; > + int perf_id; > > - cgrp = BPF_CORE_READ(p, cgroups, subsys[perf_event_cgrp_id], cgroup); > + perf_id = bpf_core_enum_value(enum cgroup_subsys_id, perf_event_cgrp_id); > + cgrp = BPF_CORE_READ(p, cgroups, subsys[perf_id], cgroup); LGTM, do we need the same fix in off cpu? https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/tree/tools/perf/util/bpf_skel/off_cpu.bpf.c?h=perf/core#n123 Thanks, Ian > level = BPF_CORE_READ(cgrp, level); > > for (cnt = 0; i < MAX_LEVELS; i++) { > -- > 2.37.3.968.ga6b4b080e4-goog >
Hi Ian, On Wed, Sep 21, 2022 at 8:54 PM Ian Rogers <irogers@google.com> wrote: > > On Wed, Sep 21, 2022 at 8:33 PM Namhyung Kim <namhyung@kernel.org> wrote: > > > > The perf_event_cgrp_id can be different on other configurations. > > To be more portable as CO-RE, it needs to get the cgroup subsys id > > using the bpf_core_enum_value() helper. > > > > Suggested-by: Ian Rogers <irogers@google.com> > > Signed-off-by: Namhyung Kim <namhyung@kernel.org> > > --- > > tools/perf/util/bpf_skel/bperf_cgroup.bpf.c | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c b/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c > > index c72f8ad96f75..35a8e38d3ee3 100644 > > --- a/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c > > +++ b/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c > > @@ -57,8 +57,10 @@ static inline int get_cgroup_v1_idx(__u32 *cgrps, int size) > > __u32 *elem; > > int level; > > int cnt; > > + int perf_id; > > > > - cgrp = BPF_CORE_READ(p, cgroups, subsys[perf_event_cgrp_id], cgroup); > > + perf_id = bpf_core_enum_value(enum cgroup_subsys_id, perf_event_cgrp_id); > > + cgrp = BPF_CORE_READ(p, cgroups, subsys[perf_id], cgroup); > > LGTM, do we need the same fix in off cpu? > https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/tree/tools/perf/util/bpf_skel/off_cpu.bpf.c?h=perf/core#n123 Right, will send v2. Thanks, Namhyung
diff --git a/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c b/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c index c72f8ad96f75..35a8e38d3ee3 100644 --- a/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c +++ b/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c @@ -57,8 +57,10 @@ static inline int get_cgroup_v1_idx(__u32 *cgrps, int size) __u32 *elem; int level; int cnt; + int perf_id; - cgrp = BPF_CORE_READ(p, cgroups, subsys[perf_event_cgrp_id], cgroup); + perf_id = bpf_core_enum_value(enum cgroup_subsys_id, perf_event_cgrp_id); + cgrp = BPF_CORE_READ(p, cgroups, subsys[perf_id], cgroup); level = BPF_CORE_READ(cgrp, level); for (cnt = 0; i < MAX_LEVELS; i++) {
The perf_event_cgrp_id can be different on other configurations. To be more portable as CO-RE, it needs to get the cgroup subsys id using the bpf_core_enum_value() helper. Suggested-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> --- tools/perf/util/bpf_skel/bperf_cgroup.bpf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)