From: Steven Rostedt <rostedt@goodmis.org>
Date: Mon, 12 May 2008 19:20:58 +0000 (+0200)
Subject: ftrace: allow trace_pipe to block on all reads
X-Git-Tag: v2.6.27-rc1~1102^2^2~1^2~57
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8487c23765b6e0444ec6b5f1530766d63fe68e35;p=linux-2.6

ftrace: allow trace_pipe to block on all reads

We expect things like "cat" to block on reads to trace_pipe. That's what
trace_pipe is for.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 9197782d15..fd4ecc2920 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2231,8 +2231,6 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
 	start = 0;
 
 	while (trace_empty(iter)) {
-		if (!(trace_flags & TRACE_ITER_BLOCK))
-			return -EWOULDBLOCK;
 		/*
 		 * This is a make-shift waitqueue. The reason we don't use
 		 * an actual wait queue is because: