Messages in this thread Patch in this message | | | From | Namhyung Kim <> | Subject | [PATCH 2/4] perf tools: Add cgroup_is_v2() helper | Date | Fri, 25 Jun 2021 00:18:24 -0700 |
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The cgroup_is_v2() is to check if the given subsystem is mounted on cgroup v2 or not. It'll be used by BPF cgroup code later.
Signed-off-by: Namhyung Kim <namhyung@kernel.org> --- tools/perf/util/cgroup.c | 19 +++++++++++++++++++ tools/perf/util/cgroup.h | 2 ++ 2 files changed, 21 insertions(+)
diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c index ef18c988c681..e819a4f30fc2 100644 --- a/tools/perf/util/cgroup.c +++ b/tools/perf/util/cgroup.c @@ -9,6 +9,7 @@ #include <linux/zalloc.h> #include <sys/types.h> #include <sys/stat.h> +#include <sys/statfs.h> #include <fcntl.h> #include <stdlib.h> #include <string.h> @@ -70,6 +71,24 @@ int read_cgroup_id(struct cgroup *cgrp) } #endif /* HAVE_FILE_HANDLE */ +#ifndef CGROUP2_SUPER_MAGIC +#define CGROUP2_SUPER_MAGIC 0x63677270 +#endif + +int cgroup_is_v2(const char *subsys) +{ + char mnt[PATH_MAX + 1]; + struct statfs stbuf; + + if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1, subsys)) + return -1; + + if (statfs(mnt, &stbuf) < 0) + return -1; + + return (stbuf.f_type == CGROUP2_SUPER_MAGIC); +} + static struct cgroup *evlist__find_cgroup(struct evlist *evlist, const char *str) { struct evsel *counter; diff --git a/tools/perf/util/cgroup.h b/tools/perf/util/cgroup.h index 707adbe25123..1549ec2fd348 100644 --- a/tools/perf/util/cgroup.h +++ b/tools/perf/util/cgroup.h @@ -47,4 +47,6 @@ int read_cgroup_id(struct cgroup *cgrp) } #endif /* HAVE_FILE_HANDLE */ +int cgroup_is_v2(const char *subsys); + #endif /* __CGROUP_H__ */ -- 2.32.0.93.g670b81a890-goog
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