Commit 21bcc726 authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
Browse files

perf tools: Add cgroup_is_v2() helper 



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: default avatarNamhyung Kim <namhyung@kernel.org>
Acked-by: default avatarIan Rogers <irogers@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210625071826.608504-3-namhyung@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 69e874db

tools/perf/util/cgroup.c

+19 −0
Original line number Diff line number Diff line
@@ -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;

tools/perf/util/cgroup.h

+2 −0
Original line number Diff line number Diff line
@@ -48,4 +48,6 @@ static inline int read_cgroup_id(struct cgroup *cgrp __maybe_unused) 
}

#endif  /* HAVE_FILE_HANDLE */



int cgroup_is_v2(const char *subsys);



#endif /* __CGROUP_H__ */