Commit 5f43ba29 authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Alasdair G Kergon
Browse files

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: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent bda8efec

drivers/md/dm-kcopyd.c

+3 −3
Original line number Diff line number Diff line
@@ -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 @@ int kcopyd_cancel(struct kcopyd_job *job, int block) 
/*-----------------------------------------------------------------

 * 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 @@ int dm_kcopyd_client_create(unsigned min_pages, 


	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;

drivers/md/dm-raid1.c

+1 −2
Original line number Diff line number Diff line
@@ -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 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
		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;

drivers/md/dm-snap.c

+1 −6
Original line number Diff line number Diff line
@@ -39,11 +39,6 @@ static const char dm_snapshot_merge_target_name[] = "snapshot-merge"; 
 */

#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.

 */
@@ -1116,7 +1111,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
		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;

include/linux/dm-kcopyd.h

+1 −2
Original line number Diff line number Diff line
@@ -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);



/*

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