aboutsummaryrefslogtreecommitdiffstats
path: root/tools/perf/perf.c
diff options
context:
space:
mode:
authorJason Baron <jbaron@redhat.com>2009-07-21 14:16:29 -0400
committerPeter Zijlstra <a.p.zijlstra@chello.nl>2009-07-22 18:05:57 +0200
commit5beeded123c5befa21f1c6e16219f2a3eb7dd197 (patch)
tree4ac812126910994516300c53171c7267b97f6f5d /tools/perf/perf.c
parentf6bdafef2ab911f03321fa83d8da1df99878009e (diff)
downloadmrst-s0i3-test-5beeded123c5befa21f1c6e16219f2a3eb7dd197.tar.gz
mrst-s0i3-test-5beeded123c5befa21f1c6e16219f2a3eb7dd197.tar.xz
mrst-s0i3-test-5beeded123c5befa21f1c6e16219f2a3eb7dd197.zip
perf_counter: Detect debugfs location
If "/sys/kernel/debug" is not a debugfs mount point, search for the debugfs filesystem in /proc/mounts, but also allows the user to specify '--debugfs-dir=blah' or set the environment variable: 'PERF_DEBUGFS_DIR' Signed-off-by: Jason Baron <jbaron@redhat.com> [ also made it probe "/debug" by default ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090721181629.GA3094@redhat.com>
Diffstat (limited to 'tools/perf/perf.c')
-rw-r--r--tools/perf/perf.c77
1 files changed, 76 insertions, 1 deletions
diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index c5656784c61..31982ad064b 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -12,6 +12,8 @@
#include "util/cache.h"
#include "util/quote.h"
#include "util/run-command.h"
+#include "util/parse-events.h"
+#include "util/string.h"
const char perf_usage_string[] =
"perf [--version] [--help] COMMAND [ARGS]";
@@ -25,6 +27,8 @@ struct pager_config {
int val;
};
+static char debugfs_mntpt[MAXPATHLEN];
+
static int pager_command_config(const char *var, const char *value, void *data)
{
struct pager_config *c = data;
@@ -56,6 +60,15 @@ static void commit_pager_choice(void) {
}
}
+static void set_debugfs_path(void)
+{
+ char *path;
+
+ path = getenv(PERF_DEBUGFS_ENVIRONMENT);
+ snprintf(debugfs_path, MAXPATHLEN, "%s/%s", path ?: debugfs_mntpt,
+ "tracing/events");
+}
+
static int handle_options(const char*** argv, int* argc, int* envchanged)
{
int handled = 0;
@@ -122,6 +135,22 @@ static int handle_options(const char*** argv, int* argc, int* envchanged)
setenv(PERF_WORK_TREE_ENVIRONMENT, cmd + 12, 1);
if (envchanged)
*envchanged = 1;
+ } else if (!strcmp(cmd, "--debugfs-dir")) {
+ if (*argc < 2) {
+ fprintf(stderr, "No directory given for --debugfs-dir.\n");
+ usage(perf_usage_string);
+ }
+ strncpy(debugfs_mntpt, (*argv)[1], MAXPATHLEN);
+ debugfs_mntpt[MAXPATHLEN - 1] = '\0';
+ if (envchanged)
+ *envchanged = 1;
+ (*argv)++;
+ (*argc)--;
+ } else if (!prefixcmp(cmd, "--debugfs-dir=")) {
+ strncpy(debugfs_mntpt, cmd + 14, MAXPATHLEN);
+ debugfs_mntpt[MAXPATHLEN - 1] = '\0';
+ if (envchanged)
+ *envchanged = 1;
} else {
fprintf(stderr, "Unknown option: %s\n", cmd);
usage(perf_usage_string);
@@ -228,6 +257,7 @@ static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
if (use_pager == -1 && p->option & USE_PAGER)
use_pager = 1;
commit_pager_choice();
+ set_debugfs_path();
status = p->fn(argc, argv, prefix);
if (status)
@@ -346,6 +376,49 @@ static int run_argv(int *argcp, const char ***argv)
return done_alias;
}
+/* mini /proc/mounts parser: searching for "^blah /mount/point debugfs" */
+static void get_debugfs_mntpt(void)
+{
+ FILE *file;
+ char fs_type[100];
+ char debugfs[MAXPATHLEN];
+
+ /*
+ * try the standard location
+ */
+ if (valid_debugfs_mount("/sys/kernel/debug/") == 0) {
+ strcpy(debugfs_mntpt, "/sys/kernel/debug/");
+ return;
+ }
+
+ /*
+ * try the sane location
+ */
+ if (valid_debugfs_mount("/debug/") == 0) {
+ strcpy(debugfs_mntpt, "/debug/");
+ return;
+ }
+
+ /*
+ * give up and parse /proc/mounts
+ */
+ file = fopen("/proc/mounts", "r");
+ if (file == NULL)
+ return;
+
+ while (fscanf(file, "%*s %"
+ STR(MAXPATHLEN)
+ "s %99s %*s %*d %*d\n",
+ debugfs, fs_type) == 2) {
+ if (strcmp(fs_type, "debugfs") == 0)
+ break;
+ }
+ fclose(file);
+ if (strcmp(fs_type, "debugfs") == 0) {
+ strncpy(debugfs_mntpt, debugfs, MAXPATHLEN);
+ debugfs_mntpt[MAXPATHLEN - 1] = '\0';
+ }
+}
int main(int argc, const char **argv)
{
@@ -354,7 +427,8 @@ int main(int argc, const char **argv)
cmd = perf_extract_argv0_path(argv[0]);
if (!cmd)
cmd = "perf-help";
-
+ /* get debugfs mount point from /proc/mounts */
+ get_debugfs_mntpt();
/*
* "perf-xxxx" is the same as "perf xxxx", but we obviously:
*
@@ -377,6 +451,7 @@ int main(int argc, const char **argv)
argc--;
handle_options(&argv, &argc, NULL);
commit_pager_choice();
+ set_debugfs_path();
if (argc > 0) {
if (!prefixcmp(argv[0], "--"))
argv[0] += 2;