dm kcopyd: reserve fewer pages
Reserve just the minimum of pages needed to process one job.
Because we allocate pages from page allocator, we don't need to reserve
a large number of pages. The maximum job size is SUB_JOB_SIZE and we
calculate the number of reserved pages based on this.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-kcopyd.c b/drivers/md/dm-kcopyd.c
index 7196933..579647f 100644
--- a/drivers/md/dm-kcopyd.c
+++ b/drivers/md/dm-kcopyd.c
@@ -30,6 +30,7 @@
#define SUB_JOB_SIZE 128
#define SPLIT_COUNT 8
#define MIN_JOBS 8
+#define RESERVE_PAGES (DIV_ROUND_UP(SUB_JOB_SIZE << SECTOR_SHIFT, PAGE_SIZE))
/*-----------------------------------------------------------------
* Each kcopyd client has its own little pool of preallocated
@@ -636,8 +637,7 @@
/*-----------------------------------------------------------------
* Client setup
*---------------------------------------------------------------*/
-int dm_kcopyd_client_create(unsigned min_pages,
- struct dm_kcopyd_client **result)
+int dm_kcopyd_client_create(struct dm_kcopyd_client **result)
{
int r = -ENOMEM;
struct dm_kcopyd_client *kc;
@@ -663,7 +663,7 @@
kc->pages = NULL;
kc->nr_reserved_pages = kc->nr_free_pages = 0;
- r = client_reserve_pages(kc, min_pages);
+ r = client_reserve_pages(kc, RESERVE_PAGES);
if (r)
goto bad_client_pages;
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 53089aa..9defad0 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -22,7 +22,6 @@
#define DM_MSG_PREFIX "raid1"
#define MAX_RECOVERY 1 /* Maximum number of regions recovered in parallel. */
-#define DM_KCOPYD_PAGES 64
#define DM_RAID1_HANDLE_ERRORS 0x01
#define errors_handled(p) ((p)->features & DM_RAID1_HANDLE_ERRORS)
@@ -1116,7 +1115,7 @@
goto err_destroy_wq;
}
- r = dm_kcopyd_client_create(DM_KCOPYD_PAGES, &ms->kcopyd_client);
+ r = dm_kcopyd_client_create(&ms->kcopyd_client);
if (r)
goto err_destroy_wq;
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index a2d3309..5a2296d 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -40,11 +40,6 @@
#define SNAPSHOT_COPY_PRIORITY 2
/*
- * Reserve 1MB for each snapshot initially (with minimum of 1 page).
- */
-#define SNAPSHOT_PAGES (((1UL << 20) >> PAGE_SHIFT) ? : 1)
-
-/*
* The size of the mempool used to track chunks in use.
*/
#define MIN_IOS 256
@@ -1116,7 +1111,7 @@
goto bad_hash_tables;
}
- r = dm_kcopyd_client_create(SNAPSHOT_PAGES, &s->kcopyd_client);
+ r = dm_kcopyd_client_create(&s->kcopyd_client);
if (r) {
ti->error = "Could not create kcopyd client";
goto bad_kcopyd;
diff --git a/include/linux/dm-kcopyd.h b/include/linux/dm-kcopyd.h
index 5db21631..312513d 100644
--- a/include/linux/dm-kcopyd.h
+++ b/include/linux/dm-kcopyd.h
@@ -25,8 +25,7 @@
* To use kcopyd you must first create a dm_kcopyd_client object.
*/
struct dm_kcopyd_client;
-int dm_kcopyd_client_create(unsigned num_pages,
- struct dm_kcopyd_client **result);
+int dm_kcopyd_client_create(struct dm_kcopyd_client **result);
void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc);
/*