sched: scheduler debugging, core

scheduler debugging core: implement /proc/sched_debug and
/proc/<PID>/sched files for scheduler debugging.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 69 insertions, 0 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 0f40e820c7fd..46ea5d56e1bb 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -929,6 +929,69 @@ static const struct file_operations proc_fault_inject_operations = {
 };
 #endif
 
+#ifdef CONFIG_SCHED_DEBUG
+/*
+ * Print out various scheduling related per-task fields:
+ */
+static int sched_show(struct seq_file *m, void *v)
+{
+        struct inode *inode = m->private;
+        struct task_struct *p;
+
+        WARN_ON(!inode);
+
+        p = get_proc_task(inode);
+        if (!p)
+                return -ESRCH;
+        proc_sched_show_task(p, m);
+
+        put_task_struct(p);
+
+        return 0;
+}
+
+static ssize_t
+sched_write(struct file *file, const char __user *buf,
+            size_t count, loff_t *offset)
+{
+        struct inode *inode = file->f_path.dentry->d_inode;
+        struct task_struct *p;
+
+        WARN_ON(!inode);
+
+        p = get_proc_task(inode);
+        if (!p)
+                return -ESRCH;
+        proc_sched_set_task(p);
+
+        put_task_struct(p);
+
+        return count;
+}
+
+static int sched_open(struct inode *inode, struct file *filp)
+{
+        int ret;
+
+        ret = single_open(filp, sched_show, NULL);
+        if (!ret) {
+                struct seq_file *m = filp->private_data;
+
+                m->private = inode;
+        }
+        return ret;
+}
+
+static const struct file_operations proc_pid_sched_operations = {
+        .open           = sched_open,
+        .read           = seq_read,
+        .write          = sched_write,
+        .llseek         = seq_lseek,
+        .release        = seq_release,
+};
+
+#endif
+
 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
         struct inode *inode = dentry->d_inode;
@@ -1963,6 +2026,9 @@ static const struct pid_entry tgid_base_stuff[] = {
         INF("environ",    S_IRUSR, pid_environ),
         INF("auxv",       S_IRUSR, pid_auxv),
         INF("status",     S_IRUGO, pid_status),
+#ifdef CONFIG_SCHED_DEBUG
+        REG("sched",      S_IRUGO|S_IWUSR, pid_sched),
+#endif
         INF("cmdline",    S_IRUGO, pid_cmdline),
         INF("stat",       S_IRUGO, tgid_stat),
         INF("statm",      S_IRUGO, pid_statm),
@@ -2247,6 +2313,9 @@ static const struct pid_entry tid_base_stuff[] = {
         INF("environ",   S_IRUSR, pid_environ),
         INF("auxv",      S_IRUSR, pid_auxv),
         INF("status",    S_IRUGO, pid_status),
+#ifdef CONFIG_SCHED_DEBUG
+        REG("sched",     S_IRUGO|S_IWUSR, pid_sched),
+#endif
         INF("cmdline",   S_IRUGO, pid_cmdline),
         INF("stat",      S_IRUGO, tid_stat),
         INF("statm",     S_IRUGO, pid_statm),