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From: Chris Metcalf <cmetcalf@tilera.com>
To: linux-kernel@vger.kernel.org
To: linuxppc-dev@lists.ozlabs.org
Subject: [PATCH] drivers/char/hvc_console.c: reduce max idle timeout
Date: Wed, 27 Oct 2010 12:54:27 -0400	[thread overview]
Message-ID: <201010271659.o9RGxrMc009847@farm-0002.internal.tilera.com> (raw)

The tile architecture uses this framework for our serial console,
and our users complain that the delay of up to two seconds feels like
the machine has gone non-responsive and is disturbing.  By contrast,
a delay of up to half a second feels like just the normal sort of
delay caused by swapping, network lag, etc. and is not noticeable.
The overhead is obviously not much greater.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
---

I'm happy to push this via the tile tree if the linuxppc-dev folks
want to give me an acked-by, or you can take it into your tree.  Thanks!

 drivers/char/hvc_console.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c
index 3afd62e..1df5431 100644
--- a/drivers/char/hvc_console.c
+++ b/drivers/char/hvc_console.c
@@ -565,11 +565,11 @@ static int hvc_chars_in_buffer(struct tty_struct *tty)
  * and during console activity we will use a default MIN_TIMEOUT of 10.  When
  * the console is idle, we increase the timeout value on each pass through
  * msleep until we reach the max.  This may be noticeable as a brief (average
- * one second) delay on the console before the console responds to input when
+ * 0.25 second) delay on the console before the console responds to input when
  * there has been no input for some time.
  */
 #define MIN_TIMEOUT		(10)
-#define MAX_TIMEOUT		(2000)
+#define MAX_TIMEOUT		(500)
 static u32 timeout = MIN_TIMEOUT;
 
 #define HVC_POLL_READ	0x00000001
-- 
1.6.5.2


             reply	other threads:[~2010-10-27 16:59 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-27 16:54 Chris Metcalf [this message]
2010-10-27 19:21 ` [PATCH] drivers/char/hvc_console.c: reduce max idle timeout Alan Cox
2010-10-27 19:21   ` Alan Cox
2010-10-27 19:46   ` Chris Metcalf
2010-10-27 19:46     ` Chris Metcalf
2010-11-02  0:35 ` Michael Ellerman
2010-11-02  0:35   ` Michael Ellerman
2010-11-02  2:21   ` Chris Metcalf
2010-11-02  2:21     ` Chris Metcalf

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