Commit 2dc8f095 authored by Steven Rostedt's avatar Steven Rostedt Committed by Thomas Gleixner
Browse files

ftrace: trace_pipe implement NONBLOCK



This patch implements "NONBLOCK" for trace_pipe. If the trace_pipe is opened
with O_NONBLOCK, then the trace_pipe read will not block when buffer is empty.
Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 84527997
......@@ -2233,6 +2233,10 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
start = 0;
while (trace_empty(iter)) {
if ((filp->f_flags & O_NONBLOCK))
return -EAGAIN;
/*
* This is a make-shift waitqueue. The reason we don't use
* an actual wait queue is because:
......
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