Hi
Here I'm sending new kcopyd throttling patches that allow the throttle to
be set per module (i.e. one throttle for mirror and the other for
snapshots).
Mikulas
---
dm-kcopyd: introduce per-module throttle structure
The structure contains the throttle parameter (it could be set in
/sys/module/*/parameters and auxulary variables for activity counting.
The throttle does nothing, it will be activated in the next patch.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
---
drivers/md/dm-kcopyd.c | 2 +-
drivers/md/dm-raid1.c | 5 ++++-
drivers/md/dm-snap.c | 5 ++++-
include/linux/dm-kcopyd.h | 15 ++++++++++++++-
4 files changed, 23 insertions(+), 4 deletions(-)
Index: linux-2.6.39-fast/drivers/md/dm-kcopyd.c
===================================================================
--- linux-2.6.39-fast.orig/drivers/md/dm-kcopyd.c 2011-05-31 23:46:18.000000000 +0200
+++ linux-2.6.39-fast/drivers/md/dm-kcopyd.c 2011-05-31 23:49:47.000000000 +0200
@@ -617,7 +617,7 @@ int kcopyd_cancel(struct kcopyd_job *job
/*-----------------------------------------------------------------
* Client setup
*---------------------------------------------------------------*/
-struct dm_kcopyd_client *dm_kcopyd_client_create(void)
+struct dm_kcopyd_client *dm_kcopyd_client_create(struct dm_kcopyd_throttle *throttle)
{
int r = -ENOMEM;
struct dm_kcopyd_client *kc;
Index: linux-2.6.39-fast/drivers/md/dm-raid1.c
===================================================================
--- linux-2.6.39-fast.orig/drivers/md/dm-raid1.c 2011-05-31 23:46:18.000000000 +0200
+++ linux-2.6.39-fast/drivers/md/dm-raid1.c 2011-05-31 23:46:22.000000000 +0200
@@ -83,6 +83,9 @@ struct mirror_set {
struct mirror mirror[0];
};
+dm_kcopyd_throttle_declare(raid1_resync_throttle,
+ "A percentage of time allocated for raid resynchronization");
+
static void wakeup_mirrord(void *context)
{
struct mirror_set *ms = context;
@@ -1115,7 +1118,7 @@ static int mirror_ctr(struct dm_target *
goto err_destroy_wq;
}
- ms->kcopyd_client = dm_kcopyd_client_create();
+ ms->kcopyd_client = dm_kcopyd_client_create(&dm_kcopyd_throttle);
if (IS_ERR(ms->kcopyd_client)) {
r = PTR_ERR(ms->kcopyd_client);
goto err_destroy_wq;
Index: linux-2.6.39-fast/drivers/md/dm-snap.c
===================================================================
--- linux-2.6.39-fast.orig/drivers/md/dm-snap.c 2011-05-31 23:46:18.000000000 +0200
+++ linux-2.6.39-fast/drivers/md/dm-snap.c 2011-05-31 23:46:22.000000000 +0200
@@ -135,6 +135,9 @@ struct dm_snapshot {
#define RUNNING_MERGE 0
#define SHUTDOWN_MERGE 1
+dm_kcopyd_throttle_declare(snapshot_copy_throttle,
+ "A percentage of time allocated for copy on write");
+
struct dm_dev *dm_snap_origin(struct dm_snapshot *s)
{
return s->origin;
@@ -1111,7 +1114,7 @@ static int snapshot_ctr(struct dm_target
goto bad_hash_tables;
}
- s->kcopyd_client = dm_kcopyd_client_create();
+ s->kcopyd_client = dm_kcopyd_client_create(&dm_kcopyd_throttle);
if (IS_ERR(s->kcopyd_client)) {
r = PTR_ERR(s->kcopyd_client);
ti->error = "Could not create kcopyd client";
Index: linux-2.6.39-fast/include/linux/dm-kcopyd.h
===================================================================
--- linux-2.6.39-fast.orig/include/linux/dm-kcopyd.h 2011-05-31 23:46:18.000000000 +0200
+++ linux-2.6.39-fast/include/linux/dm-kcopyd.h 2011-05-31 23:46:22.000000000 +0200
@@ -21,11 +21,24 @@
#define DM_KCOPYD_IGNORE_ERROR 1
+struct dm_kcopyd_throttle {
+ unsigned throttle;
+ unsigned long num_io_jobs;
+ unsigned io_period;
+ unsigned total_period;
+ unsigned last_jiffies;
+};
+
+#define dm_kcopyd_throttle_declare(name, description) \
+static struct dm_kcopyd_throttle dm_kcopyd_throttle = { 100, 0, 0, 0, 0 }; \
+module_param_named(name, dm_kcopyd_throttle.throttle, uint, 0644); \
+MODULE_PARM_DESC(name, description)
+
/*
* To use kcopyd you must first create a dm_kcopyd_client object.
*/
struct dm_kcopyd_client;
-struct dm_kcopyd_client *dm_kcopyd_client_create(void);
+struct dm_kcopyd_client *dm_kcopyd_client_create(struct dm_kcopyd_throttle *throttle);
void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc);
/*
--
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