In case one wants to show stats via debugfs.
Signed-off-by: Andrzej Hajda <[email protected]>
Reviewed-by: Chris Wilson <[email protected]>
---
include/linux/ref_tracker.h | 8 ++++++
lib/ref_tracker.c | 56 +++++++++++++++++++++++++++++++------
2 files changed, 56 insertions(+), 8 deletions(-)
diff --git a/include/linux/ref_tracker.h b/include/linux/ref_tracker.h
index a2cf1f6309adb..2fdbfd2e14797 100644
--- a/include/linux/ref_tracker.h
+++ b/include/linux/ref_tracker.h
@@ -50,6 +50,8 @@ void __ref_tracker_dir_print(struct ref_tracker_dir *dir,
void ref_tracker_dir_print(struct ref_tracker_dir *dir,
unsigned int display_limit);
+int ref_tracker_dir_snprint(struct ref_tracker_dir *dir, char *buf, size_t size);
+
int ref_tracker_alloc(struct ref_tracker_dir *dir,
struct ref_tracker **trackerp, gfp_t gfp);
@@ -78,6 +80,12 @@ static inline void ref_tracker_dir_print(struct ref_tracker_dir *dir,
{
}
+static inline int ref_tracker_dir_snprint(struct ref_tracker_dir *dir,
+ char *buf, size_t size)
+{
+ return 0;
+}
+
static inline int ref_tracker_alloc(struct ref_tracker_dir *dir,
struct ref_tracker **trackerp,
gfp_t gfp)
diff --git a/lib/ref_tracker.c b/lib/ref_tracker.c
index ab1253fde244e..2ef4596b6b36f 100644
--- a/lib/ref_tracker.c
+++ b/lib/ref_tracker.c
@@ -62,8 +62,27 @@ ref_tracker_get_stats(struct ref_tracker_dir *dir, unsigned int limit)
return stats;
}
-void __ref_tracker_dir_print(struct ref_tracker_dir *dir,
- unsigned int display_limit)
+struct ostream {
+ char *buf;
+ int size, used;
+};
+
+#define pr_ostream(stream, fmt, args...) \
+({ \
+ struct ostream *_s = (stream); \
+\
+ if (!_s->buf) { \
+ pr_err(fmt, ##args); \
+ } else { \
+ int ret, len = _s->size - _s->used; \
+ ret = snprintf(_s->buf + _s->used, len, pr_fmt(fmt), ##args); \
+ _s->used += min(ret, len); \
+ } \
+})
+
+static void
+__ref_tracker_dir_pr_ostream(struct ref_tracker_dir *dir,
+ unsigned int display_limit, struct ostream *s)
{
struct ref_tracker_dir_stats *stats;
unsigned int i = 0, skipped;
@@ -77,8 +96,8 @@ void __ref_tracker_dir_print(struct ref_tracker_dir *dir,
stats = ref_tracker_get_stats(dir, display_limit);
if (IS_ERR(stats)) {
- pr_err("%s@%pK: couldn't get stats, error %pe\n",
- dir->name, dir, stats);
+ pr_ostream(s, "%s@%pK: couldn't get stats, error %pe\n",
+ dir->name, dir, stats);
return;
}
@@ -88,19 +107,27 @@ void __ref_tracker_dir_print(struct ref_tracker_dir *dir,
stack = stats->stacks[i].stack_handle;
if (sbuf && !stack_depot_snprint(stack, sbuf, STACK_BUF_SIZE, 4))
sbuf[0] = 0;
- pr_err("%s@%pK has %d/%d users at\n%s\n", dir->name, dir,
- stats->stacks[i].count, stats->total, sbuf);
+ pr_ostream(s, "%s@%pK has %d/%d users at\n%s\n", dir->name, dir,
+ stats->stacks[i].count, stats->total, sbuf);
skipped -= stats->stacks[i].count;
}
if (skipped)
- pr_err("%s@%pK skipped reports about %d/%d users.\n",
- dir->name, dir, skipped, stats->total);
+ pr_ostream(s, "%s@%pK skipped reports about %d/%d users.\n",
+ dir->name, dir, skipped, stats->total);
kfree(sbuf);
kfree(stats);
}
+
+void __ref_tracker_dir_print(struct ref_tracker_dir *dir,
+ unsigned int display_limit)
+{
+ struct ostream os = {};
+
+ __ref_tracker_dir_pr_ostream(dir, display_limit, &os);
+}
EXPORT_SYMBOL(__ref_tracker_dir_print);
void ref_tracker_dir_print(struct ref_tracker_dir *dir,
@@ -114,6 +141,19 @@ void ref_tracker_dir_print(struct ref_tracker_dir *dir,
}
EXPORT_SYMBOL(ref_tracker_dir_print);
+int ref_tracker_dir_snprint(struct ref_tracker_dir *dir, char *buf, size_t size)
+{
+ struct ostream os = { .buf = buf, .size = size };
+ unsigned long flags;
+
+ spin_lock_irqsave(&dir->lock, flags);
+ __ref_tracker_dir_pr_ostream(dir, 16, &os);
+ spin_unlock_irqrestore(&dir->lock, flags);
+
+ return os.used;
+}
+EXPORT_SYMBOL(ref_tracker_dir_snprint);
+
void ref_tracker_dir_exit(struct ref_tracker_dir *dir)
{
struct ref_tracker *tracker, *n;
--
2.25.1