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authorJens Axboe <jens.axboe@oracle.com>2007-04-02 10:06:42 +0200
committerJens Axboe <axboe@nelson.home.kernel.dk>2007-04-30 09:08:17 +0200
commit5972511b77809cb7c9ccdb79b825c54921c5c546 (patch)
tree8dec5821badf9750be04f339f0f621fab2114c8a
parentMerge branch 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/netdev-2.6 (diff)
downloadlinux-dev-5972511b77809cb7c9ccdb79b825c54921c5c546.tar.xz
linux-dev-5972511b77809cb7c9ccdb79b825c54921c5c546.zip
[BLOCK] Don't pin lots of memory in mempools
Currently we scale the mempool sizes depending on memory installed in the machine, except for the bio pool itself which sits at a fixed 256 entry pre-allocation. There's really no point in "optimizing" this OOM path, we just need enough preallocated to make progress. A single unit is enough, lets scale it down to 2 just to be on the safe side. This patch saves ~150kb of pinned kernel memory on a 32-bit box. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
-rw-r--r--drivers/md/dm-crypt.c2
-rw-r--r--drivers/md/dm-io.c2
-rw-r--r--drivers/md/dm.c2
-rw-r--r--drivers/scsi/scsi_lib.c2
-rw-r--r--fs/bio.c41
-rw-r--r--include/linux/bio.h2
6 files changed, 11 insertions, 40 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 4c2471ee054a..d8121234c347 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -867,7 +867,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
goto bad4;
}
- cc->bs = bioset_create(MIN_IOS, MIN_IOS, 4);
+ cc->bs = bioset_create(MIN_IOS, MIN_IOS);
if (!cc->bs) {
ti->error = "Cannot allocate crypt bioset";
goto bad_bs;
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 4eb73d395213..8bdc8a87b249 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -60,7 +60,7 @@ static int resize_pool(unsigned int new_ios)
if (!_io_pool)
return -ENOMEM;
- _bios = bioset_create(16, 16, 4);
+ _bios = bioset_create(16, 16);
if (!_bios) {
mempool_destroy(_io_pool);
_io_pool = NULL;
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 3668b170ea68..11a98df298ec 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1012,7 +1012,7 @@ static struct mapped_device *alloc_dev(int minor)
if (!md->tio_pool)
goto bad3;
- md->bs = bioset_create(16, 16, 4);
+ md->bs = bioset_create(16, 16);
if (!md->bs)
goto bad_no_bioset;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 9f7482d0b594..05d79af5ab90 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -31,7 +31,7 @@
#define SG_MEMPOOL_NR ARRAY_SIZE(scsi_sg_pools)
-#define SG_MEMPOOL_SIZE 32
+#define SG_MEMPOOL_SIZE 2
struct scsi_host_sg_pool {
size_t size;
diff --git a/fs/bio.c b/fs/bio.c
index 7618bcb18368..693940da4090 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -28,7 +28,7 @@
#include <linux/blktrace_api.h>
#include <scsi/sg.h> /* for struct sg_iovec */
-#define BIO_POOL_SIZE 256
+#define BIO_POOL_SIZE 2
static struct kmem_cache *bio_slab __read_mostly;
@@ -38,7 +38,7 @@ static struct kmem_cache *bio_slab __read_mostly;
* a small number of entries is fine, not going to be performance critical.
* basically we just need to survive
*/
-#define BIO_SPLIT_ENTRIES 8
+#define BIO_SPLIT_ENTRIES 2
mempool_t *bio_split_pool __read_mostly;
struct biovec_slab {
@@ -1120,7 +1120,7 @@ struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors)
* create memory pools for biovec's in a bio_set.
* use the global biovec slabs created for general use.
*/
-static int biovec_create_pools(struct bio_set *bs, int pool_entries, int scale)
+static int biovec_create_pools(struct bio_set *bs, int pool_entries)
{
int i;
@@ -1128,9 +1128,6 @@ static int biovec_create_pools(struct bio_set *bs, int pool_entries, int scale)
struct biovec_slab *bp = bvec_slabs + i;
mempool_t **bvp = bs->bvec_pools + i;
- if (pool_entries > 1 && i >= scale)
- pool_entries >>= 1;
-
*bvp = mempool_create_slab_pool(pool_entries, bp->slab);
if (!*bvp)
return -ENOMEM;
@@ -1161,7 +1158,7 @@ void bioset_free(struct bio_set *bs)
kfree(bs);
}
-struct bio_set *bioset_create(int bio_pool_size, int bvec_pool_size, int scale)
+struct bio_set *bioset_create(int bio_pool_size, int bvec_pool_size)
{
struct bio_set *bs = kzalloc(sizeof(*bs), GFP_KERNEL);
@@ -1172,7 +1169,7 @@ struct bio_set *bioset_create(int bio_pool_size, int bvec_pool_size, int scale)
if (!bs->bio_pool)
goto bad;
- if (!biovec_create_pools(bs, bvec_pool_size, scale))
+ if (!biovec_create_pools(bs, bvec_pool_size))
return bs;
bad:
@@ -1196,38 +1193,12 @@ static void __init biovec_init_slabs(void)
static int __init init_bio(void)
{
- int megabytes, bvec_pool_entries;
- int scale = BIOVEC_NR_POOLS;
-
bio_slab = kmem_cache_create("bio", sizeof(struct bio), 0,
SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
biovec_init_slabs();
- megabytes = nr_free_pages() >> (20 - PAGE_SHIFT);
-
- /*
- * find out where to start scaling
- */
- if (megabytes <= 16)
- scale = 0;
- else if (megabytes <= 32)
- scale = 1;
- else if (megabytes <= 64)
- scale = 2;
- else if (megabytes <= 96)
- scale = 3;
- else if (megabytes <= 128)
- scale = 4;
-
- /*
- * Limit number of entries reserved -- mempools are only used when
- * the system is completely unable to allocate memory, so we only
- * need enough to make progress.
- */
- bvec_pool_entries = 1 + scale;
-
- fs_bio_set = bioset_create(BIO_POOL_SIZE, bvec_pool_entries, scale);
+ fs_bio_set = bioset_create(BIO_POOL_SIZE, 2);
if (!fs_bio_set)
panic("bio: can't allocate bios\n");
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 08daf3272c02..4d85262b4fa4 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -276,7 +276,7 @@ extern struct bio_pair *bio_split(struct bio *bi, mempool_t *pool,
extern mempool_t *bio_split_pool;
extern void bio_pair_release(struct bio_pair *dbio);
-extern struct bio_set *bioset_create(int, int, int);
+extern struct bio_set *bioset_create(int, int);
extern void bioset_free(struct bio_set *);
extern struct bio *bio_alloc(gfp_t, int);