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;