tracing: splice support for tracing_pipe

Added and implemented tracing_pipe_fops->splice_read(). This allows
userspace programs to get tracing data more efficiently.

Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 7b0518adf6d7..dbff0207b213 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -353,6 +353,12 @@ struct tracer {
         ssize_t                 (*read)(struct trace_iterator *iter,
                                         struct file *filp, char __user *ubuf,
                                         size_t cnt, loff_t *ppos);
+        ssize_t                 (*splice_read)(struct trace_iterator *iter,
+                                               struct file *filp,
+                                               loff_t *ppos,
+                                               struct pipe_inode_info *pipe,
+                                               size_t len,
+                                               unsigned int flags);
 #ifdef CONFIG_FTRACE_STARTUP_TEST
         int                     (*selftest)(struct tracer *trace,
                                             struct trace_array *tr);