### Comments for ChangeSet
Get multipath to use mempool
... rather than maintaining it's own mempool
----------- Diffstat output ------------
./drivers/md/multipath.c | 110 ++++++---------------------------------
./include/linux/raid/multipath.h | 11 ---
2 files changed, 19 insertions(+), 102 deletions(-)
--- ./drivers/md/multipath.c 2002/07/18 11:58:06 1.3
+++ ./drivers/md/multipath.c 2002/07/18 11:59:52 1.4
@@ -58,87 +58,20 @@ struct multipath_bh *multipath_retry_lis
static int multipath_spare_write(mddev_t *, int);
static int multipath_spare_active(mddev_t *mddev, mdp_disk_t **d);
-static struct multipath_bh *multipath_alloc_mpbh(multipath_conf_t *conf)
+static void *mp_pool_alloc(int gfp_flags, void *data)
{
- struct multipath_bh *mp_bh = NULL;
-
- do {
- spin_lock_irq(&conf->device_lock);
- if (!conf->freer1_blocked && conf->freer1) {
- mp_bh = conf->freer1;
- conf->freer1 = mp_bh->next_mp;
- conf->freer1_cnt--;
- mp_bh->next_mp = NULL;
- mp_bh->state = (1 << MPBH_PreAlloc);
- }
- spin_unlock_irq(&conf->device_lock);
- if (mp_bh)
- return mp_bh;
- mp_bh = (struct multipath_bh *) kmalloc(sizeof(struct multipath_bh),
- GFP_NOIO);
- if (mp_bh) {
- memset(mp_bh, 0, sizeof(*mp_bh));
- return mp_bh;
- }
- conf->freer1_blocked = 1;
- wait_disk_event(conf->wait_buffer,
- !conf->freer1_blocked ||
- conf->freer1_cnt > NR_RESERVED_BUFS/2
- );
- conf->freer1_blocked = 0;
- } while (1);
-}
-
-static inline void multipath_free_mpbh(struct multipath_bh *mp_bh)
-{
- multipath_conf_t *conf = mddev_to_conf(mp_bh->mddev);
-
- if (test_bit(MPBH_PreAlloc, &mp_bh->state)) {
- unsigned long flags;
- mp_bh->bio = NULL;
- spin_lock_irqsave(&conf->device_lock, flags);
- mp_bh->next_mp = conf->freer1;
- conf->freer1 = mp_bh;
- conf->freer1_cnt++;
- spin_unlock_irqrestore(&conf->device_lock, flags);
- wake_up(&conf->wait_buffer);
- } else {
- kfree(mp_bh);
- }
-}
-
-static int multipath_grow_mpbh (multipath_conf_t *conf, int cnt)
-{
- int i = 0;
-
- while (i < cnt) {
- struct multipath_bh *mp_bh;
- mp_bh = (struct multipath_bh*)kmalloc(sizeof(*mp_bh), GFP_KERNEL);
- if (!mp_bh)
- break;
- memset(mp_bh, 0, sizeof(*mp_bh));
- set_bit(MPBH_PreAlloc, &mp_bh->state);
- mp_bh->mddev = conf->mddev;
-
- multipath_free_mpbh(mp_bh);
- i++;
- }
- return i;
+ struct multipath_bh *mpb;
+ mpb = kmalloc(sizeof(*mpb), gfp_flags);
+ if (mpb)
+ memset(mpb, 0, sizeof(*mpb));
+ return mpb;
}
-static void multipath_shrink_mpbh(multipath_conf_t *conf)
+static void mp_pool_free(void *mpb, void *data)
{
- spin_lock_irq(&conf->device_lock);
- while (conf->freer1) {
- struct multipath_bh *mp_bh = conf->freer1;
- conf->freer1 = mp_bh->next_mp;
- conf->freer1_cnt--;
- kfree(mp_bh);
- }
- spin_unlock_irq(&conf->device_lock);
+ kfree(mpb);
}
-
static int multipath_map (mddev_t *mddev, struct block_device **bdev)
{
multipath_conf_t *conf = mddev_to_conf(mddev);
@@ -185,10 +118,11 @@ static void multipath_reschedule_retry (
static void multipath_end_bh_io (struct multipath_bh *mp_bh, int uptodate)
{
struct bio *bio = mp_bh->master_bio;
+ multipath_conf_t *conf = mddev_to_conf(mp_bh->mddev);
bio_endio(bio, uptodate);
bio_put(mp_bh->bio);
- multipath_free_mpbh(mp_bh);
+ mempool_free(mp_bh, conf->pool);
}
void multipath_end_request(struct bio *bio)
@@ -251,7 +185,7 @@ static int multipath_make_request (reque
struct multipath_bh * mp_bh;
struct multipath_info *multipath;
- mp_bh = multipath_alloc_mpbh (conf);
+ mp_bh = mempool_alloc(conf->pool, GFP_NOIO);
mp_bh->master_bio = bio;
mp_bh->mddev = mddev;
@@ -864,24 +798,15 @@ static int multipath_run (mddev_t *mddev
conf->mddev = mddev;
conf->device_lock = SPIN_LOCK_UNLOCKED;
- init_waitqueue_head(&conf->wait_buffer);
-
if (!conf->working_disks) {
printk(NONE_OPERATIONAL, mdidx(mddev));
goto out_free_conf;
}
-
- /* pre-allocate some buffer_head structures.
- * As a minimum, 1 mpbh and raid_disks buffer_heads
- * would probably get us by in tight memory situations,
- * but a few more is probably a good idea.
- * For now, try NR_RESERVED_BUFS mpbh and
- * NR_RESERVED_BUFS*raid_disks bufferheads
- * This will allow at least NR_RESERVED_BUFS concurrent
- * reads or writes even if kmalloc starts failing
- */
- if (multipath_grow_mpbh(conf, NR_RESERVED_BUFS) < NR_RESERVED_BUFS) {
+ conf->pool = mempool_create(NR_RESERVED_BUFS,
+ mp_pool_alloc, mp_pool_free,
+ NULL);
+ if (conf->pool == NULL) {
printk(MEM_ERROR, mdidx(mddev));
goto out_free_conf;
}
@@ -916,7 +841,8 @@ static int multipath_run (mddev_t *mddev
return 0;
out_free_conf:
- multipath_shrink_mpbh(conf);
+ if (conf->pool)
+ mempool_destroy(conf->pool);
kfree(conf);
mddev->private = NULL;
out:
@@ -941,7 +867,7 @@ static int multipath_stop (mddev_t *mdde
multipath_conf_t *conf = mddev_to_conf(mddev);
md_unregister_thread(conf->thread);
- multipath_shrink_mpbh(conf);
+ mempool_destroy(conf->pool);
kfree(conf);
mddev->private = NULL;
MOD_DEC_USE_COUNT;
--- ./include/linux/raid/multipath.h 2002/07/18 11:59:50 1.1
+++ ./include/linux/raid/multipath.h 2002/07/18 11:59:52 1.2
@@ -27,16 +27,7 @@ struct multipath_private_data {
struct multipath_info *spare;
spinlock_t device_lock;
- /* buffer pool */
- /* buffer_heads that we have pre-allocated have b_pprev -> &freebh
- * and are linked into a stack using b_next
- * multipath_bh that are pre-allocated have MPBH_PreAlloc set.
- * All these variable are protected by device_lock
- */
- struct multipath_bh *freer1;
- int freer1_blocked;
- int freer1_cnt;
- wait_queue_head_t wait_buffer;
+ mempool_t *pool;
};
typedef struct multipath_private_data multipath_conf_t;
-
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