Commit 69e874db authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
Browse files

perf tools: Add read_cgroup_id() function 



The read_cgroup_id() is to read a cgroup id from a file handle using
name_to_handle_at(2) for the given cgroup.  It'll be used by bperf
cgroup stat later.

Committer notes:

  -int read_cgroup_id(struct cgroup *cgrp)
  +static inline int read_cgroup_id(struct cgroup *cgrp __maybe_unused)

To fix the build when HAVE_FILE_HANDLE is not defined.

Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.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/20210625071826.608504-2-namhyung@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent f20510d5

tools/perf/util/cgroup.c

+25 −0
Original line number Diff line number Diff line
@@ -45,6 +45,31 @@ static int open_cgroup(const char *name) 
	return fd;

}



#ifdef HAVE_FILE_HANDLE

int read_cgroup_id(struct cgroup *cgrp)

{

	char path[PATH_MAX + 1];

	char mnt[PATH_MAX + 1];

	struct {

		struct file_handle fh;

		uint64_t cgroup_id;

	} handle;

	int mount_id;



	if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1, "perf_event"))

		return -1;



	scnprintf(path, PATH_MAX, "%s/%s", mnt, cgrp->name);



	handle.fh.handle_bytes = sizeof(handle.cgroup_id);

	if (name_to_handle_at(AT_FDCWD, path, &handle.fh, &mount_id, 0) < 0)

		return -1;



	cgrp->id = handle.cgroup_id;

	return 0;

}

#endif  /* HAVE_FILE_HANDLE */



static struct cgroup *evlist__find_cgroup(struct evlist *evlist, const char *str)

{

	struct evsel *counter;

tools/perf/util/cgroup.h

+10 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
#ifndef __CGROUP_H__

#define __CGROUP_H__



#include <linux/compiler.h>

#include <linux/refcount.h>

#include <linux/rbtree.h>

#include "util/env.h"
@@ -38,4 +39,13 @@ struct cgroup *cgroup__find(struct perf_env *env, uint64_t id); 


void perf_env__purge_cgroups(struct perf_env *env);



#ifdef HAVE_FILE_HANDLE

int read_cgroup_id(struct cgroup *cgrp);

#else

static inline int read_cgroup_id(struct cgroup *cgrp __maybe_unused)

{

	return -1;

}

#endif  /* HAVE_FILE_HANDLE */



#endif /* __CGROUP_H__ */