From f92c8dd7a0eb18124521e2b549f88422e17f707b Mon Sep 17 00:00:00 2001
From: Bob Peterson <rpeterso@redhat.com>
Date: Fri, 12 Nov 2010 11:15:20 -0600
Subject: dlm: reduce cond_resched during send
Calling cond_resched() after every send can unnecessarily
degrade performance. Go back to an old method of scheduling
after 25 messages.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
---
fs/dlm/lowcomms.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
(limited to 'fs/dlm')
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index 2bedb0ac5f92..0e75f152eac2 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -63,6 +63,9 @@
#define NEEDED_RMEM (4*1024*1024)
#define CONN_HASH_SIZE 32
+/* Number of messages to send before rescheduling */
+#define MAX_SEND_MSG_COUNT 25
+
struct cbuf {
unsigned int base;
unsigned int len;
@@ -1318,6 +1321,7 @@ static void send_to_sock(struct connection *con)
const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
struct writequeue_entry *e;
int len, offset;
+ int count = 0;
mutex_lock(&con->sock_mutex);
if (con->sock == NULL)
@@ -1355,8 +1359,12 @@ static void send_to_sock(struct connection *con)
if (ret <= 0)
goto send_error;
}
- /* Don't starve people filling buffers */
+
+ /* Don't starve people filling buffers */
+ if (++count >= MAX_SEND_MSG_COUNT) {
cond_resched();
+ count = 0;
+ }
spin_lock(&con->writequeue_lock);
e->offset += ret;
--
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