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Diffstat (limited to 'mm/damon/dbgfs.c')
-rw-r--r--mm/damon/dbgfs.c37
1 files changed, 35 insertions, 2 deletions
diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c
index d2e0a547eb3f..e850be4077f5 100644
--- a/mm/damon/dbgfs.c
+++ b/mm/damon/dbgfs.c
@@ -239,6 +239,32 @@ out:
return ret;
}
+static ssize_t dbgfs_kdamond_pid_read(struct file *file,
+ char __user *buf, size_t count, loff_t *ppos)
+{
+ struct damon_ctx *ctx = file->private_data;
+ char *kbuf;
+ ssize_t len;
+
+ kbuf = kmalloc(count, GFP_KERNEL);
+ if (!kbuf)
+ return -ENOMEM;
+
+ mutex_lock(&ctx->kdamond_lock);
+ if (ctx->kdamond)
+ len = scnprintf(kbuf, count, "%d\n", ctx->kdamond->pid);
+ else
+ len = scnprintf(kbuf, count, "none\n");
+ mutex_unlock(&ctx->kdamond_lock);
+ if (!len)
+ goto out;
+ len = simple_read_from_buffer(buf, count, ppos, kbuf, len);
+
+out:
+ kfree(kbuf);
+ return len;
+}
+
static int damon_dbgfs_open(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
@@ -258,10 +284,17 @@ static const struct file_operations target_ids_fops = {
.write = dbgfs_target_ids_write,
};
+static const struct file_operations kdamond_pid_fops = {
+ .open = damon_dbgfs_open,
+ .read = dbgfs_kdamond_pid_read,
+};
+
static void dbgfs_fill_ctx_dir(struct dentry *dir, struct damon_ctx *ctx)
{
- const char * const file_names[] = {"attrs", "target_ids"};
- const struct file_operations *fops[] = {&attrs_fops, &target_ids_fops};
+ const char * const file_names[] = {"attrs", "target_ids",
+ "kdamond_pid"};
+ const struct file_operations *fops[] = {&attrs_fops, &target_ids_fops,
+ &kdamond_pid_fops};
int i;
for (i = 0; i < ARRAY_SIZE(file_names); i++)