When this file is read, we print a human-readable listing of histogram
buckets, as well as the number of samples recorded in each bucket.
Signed-off-by: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
---
fs/proc/base.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index a96377557db7..42d706474971 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -96,6 +96,8 @@
#include <linux/posix-timers.h>
#include <linux/time_namespace.h>
#include <linux/resctrl.h>
+#include <linux/histogram.h>
+#include <linux/mm_types.h>
#include <trace/events/oom.h>
#include "internal.h"
#include "fd.h"
@@ -3115,6 +3117,26 @@ static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
}
#endif /* CONFIG_STACKLEAK_METRICS */
+#ifdef CONFIG_MMAP_LOCK_HISTOGRAMS
+static int proc_pid_mmap_lock_contention_show(struct seq_file *m,
+ struct pid_namespace *ns,
+ struct pid *pid,
+ struct task_struct *task)
+{
+ int rc;
+
+ if (unlikely(!task->mm->mmap_lock_contention))
+ return 0;
+
+ rc = histogram_print_buckets_rcu(
+ task->mm->mmap_lock_contention,
+ m->buf + m->count, m->size - m->count);
+ if (rc > 0)
+ m->count += rc;
+ return 0;
+}
+#endif /* CONFIG_MMAP_LOCK_HISTOGRAMS */
+
/*
* Thread groups
*/
@@ -3228,6 +3250,9 @@ static const struct pid_entry tgid_base_stuff[] = {
#ifdef CONFIG_PROC_PID_ARCH_STATUS
ONE("arch_status", S_IRUGO, proc_pid_arch_status),
#endif
+#ifdef CONFIG_MMAP_LOCK_HISTOGRAMS
+ ONE("mmap_lock_contention", S_IRUGO, proc_pid_mmap_lock_contention_show),
+#endif
};
static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
--
2.27.0.rc0.183.gde8f92d652-goog
