From 9745512ce79de686df354dc70a8d1a74d801892d Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <arjan@linux.intel.com>
Date: Fri, 25 Jan 2008 21:08:34 +0100
Subject: sched: latencytop support
LatencyTOP kernel infrastructure; it measures latencies in the
scheduler and tracks it system wide and per process.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
fs/proc/base.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 78 insertions(+)
(limited to 'fs')
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 7411bfb..91fa8e6 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -310,6 +310,77 @@ static int proc_pid_schedstat(struct task_struct *task, char *buffer)
}
#endif
+#ifdef CONFIG_LATENCYTOP
+static int lstats_show_proc(struct seq_file *m, void *v)
+{
+ int i;
+ struct task_struct *task = m->private;
+ seq_puts(m, "Latency Top version : v0.1\n");
+
+ for (i = 0; i < 32; i++) {
+ if (task->latency_record[i].backtrace[0]) {
+ int q;
+ seq_printf(m, "%i %li %li ",
+ task->latency_record[i].count,
+ task->latency_record[i].time,
+ task->latency_record[i].max);
+ for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
+ char sym[KSYM_NAME_LEN];
+ char *c;
+ if (!task->latency_record[i].backtrace[q])
+ break;
+ if (task->latency_record[i].backtrace[q] == ULONG_MAX)
+ break;
+ sprint_symbol(sym, task->latency_record[i].backtrace[q]);
+ c = strchr(sym, '+');
+ if (c)
+ *c = 0;
+ seq_printf(m, "%s ", sym);
+ }
+ seq_printf(m, "\n");
+ }
+
+ }
+ return 0;
+}
+
+static int lstats_open(struct inode *inode, struct file *file)
+{
+ int ret;
+ struct seq_file *m;
+ struct task_struct *task = get_proc_task(inode);
+
+ ret = single_open(file, lstats_show_proc, NULL);
+ if (!ret) {
+ m = file->private_data;
+ m->private = task;
+ }
+ return ret;
+}
+
+static ssize_t lstats_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *offs)
+{
+ struct seq_file *m;
+ struct task_struct *task;
+
+ m = file->private_data;
+ task = m->private;
+ clear_all_latency_tracing(task);
+
+ return count;
+}
+
+static const struct file_operations proc_lstats_operations = {
+ .open = lstats_open,
+ .read = seq_read,
+ .write = lstats_write,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+#endif
+
/* The badness from the OOM killer */
unsigned long badness(struct task_struct *p, unsigned long uptime);
static int proc_oom_score(struct task_struct *task, char *buffer)
@@ -1020,6 +1091,7 @@ static const struct file_operations proc_fault_inject_operations = {
};
#endif
+
#ifdef CONFIG_SCHED_DEBUG
/*
* Print out various scheduling related per-task fields:
@@ -2230,6 +2302,9 @@ static const struct pid_entry tgid_base_stuff[] = {
#ifdef CONFIG_SCHEDSTATS
INF("schedstat", S_IRUGO, pid_schedstat),
#endif
+#ifdef CONFIG_LATENCYTOP
+ REG("latency", S_IRUGO, lstats),
+#endif
#ifdef CONFIG_PROC_PID_CPUSET
REG("cpuset", S_IRUGO, cpuset),
#endif
@@ -2555,6 +2630,9 @@ static const struct pid_entry tid_base_stuff[] = {
#ifdef CONFIG_SCHEDSTATS
INF("schedstat", S_IRUGO, pid_schedstat),
#endif
+#ifdef CONFIG_LATENCYTOP
+ REG("latency", S_IRUGO, lstats),
+#endif
#ifdef CONFIG_PROC_PID_CPUSET
REG("cpuset", S_IRUGO, cpuset),
#endif
--
cgit v1.1