[dm-devel] [PATCH] dm-kcopyd: Add a throttle parameter

[Mikulas Patocka <mpatocka redhat com>]

dm-kcopyd: Add a throttle parameter

This patch adds a kcopyd throttle parameter accessible in
/sys/module/dm_mod/parameters/dm_kcopyd_throttle

So far, this parameter does nothing, it will be used in the next patch.

Signed-off-by: Mikulas Patocka <mpatocka redhat com>

---
 drivers/md/dm-kcopyd.c |    5 +++++
 1 file changed, 5 insertions(+)

Index: linux-2.6.39-fast/drivers/md/dm-kcopyd.c
===================================================================
--- linux-2.6.39-fast.orig/drivers/md/dm-kcopyd.c	2011-05-26 18:36:47.000000000 +0200
+++ linux-2.6.39-fast/drivers/md/dm-kcopyd.c	2011-05-26 19:23:15.000000000 +0200
@@ -66,6 +66,11 @@ struct dm_kcopyd_client {
 	struct list_head pages_jobs;
 };
 
+static unsigned dm_kcopyd_throttle = 100;
+
+module_param(dm_kcopyd_throttle, uint, 0644);
+MODULE_PARM_DESC(dm_kcopyd_throttle, "A percentage of time allocated for copying");
+
 static DEFINE_SPINLOCK(activity_spinlock);
 static unsigned long num_io_jobs = 0;