Allocate "struct io" from a slab.
This patch changes dm-io, so that "struct io" is allocated from a slab cache.
It used to be allocated with kmalloc. Allocating from a slab will be needed
for the next patch, because it requires a special alignment of "struct io"
and kmalloc cannot meet this alignment.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
---
drivers/md/dm-io.c | 19 ++++++++++++++++++-
drivers/md/dm.c | 2 ++
drivers/md/dm.h | 3 +++
3 files changed, 23 insertions(+), 1 deletion(-)
Index: linux-2.6.31.6-fast/drivers/md/dm-io.c
===================================================================
--- linux-2.6.31.6-fast.orig/drivers/md/dm-io.c 2009-11-11 00:51:03.000000000 +0100
+++ linux-2.6.31.6-fast/drivers/md/dm-io.c 2009-11-11 00:51:22.000000000 +0100
@@ -30,6 +30,8 @@ struct io {
void *context;
};
+static struct kmem_cache *_io_cache = NULL;
+
/*
* io contexts are only dynamically allocated for asynchronous
* io. Since async io is likely to be the majority of io we'll
@@ -53,7 +55,7 @@ struct dm_io_client *dm_io_client_create
if (!client)
return ERR_PTR(-ENOMEM);
- client->pool = mempool_create_kmalloc_pool(ios, sizeof(struct io));
+ client->pool = mempool_create_slab_pool(ios, _io_cache);
if (!client->pool)
goto bad;
@@ -476,3 +478,18 @@ int dm_io(struct dm_io_request *io_req,
&dp, io_req->notify.fn, io_req->notify.context);
}
EXPORT_SYMBOL(dm_io);
+
+int __init dm_io_init(void)
+{
+ _io_cache = KMEM_CACHE(io, 0);
+ if (!_io_cache)
+ return -ENOMEM;
+
+ return 0;
+}
+
+void dm_io_exit(void)
+{
+ kmem_cache_destroy(_io_cache);
+ _io_cache = NULL;
+}
Index: linux-2.6.31.6-fast/drivers/md/dm.c
===================================================================
--- linux-2.6.31.6-fast.orig/drivers/md/dm.c 2009-11-11 00:51:04.000000000 +0100
+++ linux-2.6.31.6-fast/drivers/md/dm.c 2009-11-11 00:51:22.000000000 +0100
@@ -275,6 +275,7 @@ static int (*_inits[])(void) __initdata
dm_target_init,
dm_linear_init,
dm_stripe_init,
+ dm_io_init,
dm_kcopyd_init,
dm_interface_init,
};
@@ -284,6 +285,7 @@ static void (*_exits[])(void) = {
dm_target_exit,
dm_linear_exit,
dm_stripe_exit,
+ dm_io_exit,
dm_kcopyd_exit,
dm_interface_exit,
};
Index: linux-2.6.31.6-fast/drivers/md/dm.h
===================================================================
--- linux-2.6.31.6-fast.orig/drivers/md/dm.h 2009-11-11 00:51:04.000000000 +0100
+++ linux-2.6.31.6-fast/drivers/md/dm.h 2009-11-11 00:51:22.000000000 +0100
@@ -118,6 +118,9 @@ int dm_lock_for_deletion(struct mapped_d
void dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
unsigned cookie);
+int dm_io_init(void);
+void dm_io_exit(void);
+
int dm_kcopyd_init(void);
void dm_kcopyd_exit(void);
--
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