diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2017-10-31 19:33:02 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-11-30 08:39:02 +0000 |
| commit | 67246fb9449a0cb060a7bcac72b5169fb4fb9f75 (patch) | |
| tree | ec6c30e2126a9a4d43f3bf36d2b2193566557803 /drivers/md | |
| parent | 6609a3cdfca457d4783b4e18fc91c462353927f4 (diff) | |
dm: allocate struct mapped_device with kvzalloc
commit 856eb0916d181da6d043cc33e03f54d5c5bbe54a upstream.
The structure srcu_struct can be very big, its size is proportional to the
value CONFIG_NR_CPUS. The Fedora kernel has CONFIG_NR_CPUS 8192, the field
io_barrier in the struct mapped_device has 84kB in the debugging kernel
and 50kB in the non-debugging kernel. The large size may result in failure
of the function kzalloc_node.
In order to avoid the allocation failure, we use the function
kvzalloc_node, this function falls back to vmalloc if a large contiguous
chunk of memory is not available. This patch also moves the field
io_barrier to the last position of struct mapped_device - the reason is
that on many processor architectures, short memory offsets result in
smaller code than long memory offsets - on x86-64 it reduces code size by
320 bytes.
Note to stable kernel maintainers - the kernels 4.11 and older don't have
the function kvzalloc_node, you can use the function vzalloc_node instead.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-core.h | 3 | ||||
| -rw-r--r-- | drivers/md/dm.c | 7 |
2 files changed, 6 insertions, 4 deletions
diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h index 40ceba1fe8be..1609d4971104 100644 --- a/drivers/md/dm-core.h +++ b/drivers/md/dm-core.h @@ -29,7 +29,6 @@ struct dm_kobject_holder { * DM targets must _not_ deference a mapped_device to directly access its members! */ struct mapped_device { - struct srcu_struct io_barrier; struct mutex suspend_lock; /* @@ -127,6 +126,8 @@ struct mapped_device { struct blk_mq_tag_set *tag_set; bool use_blk_mq:1; bool init_tio_pdu:1; + + struct srcu_struct io_barrier; }; void dm_init_md_queue(struct mapped_device *md); diff --git a/drivers/md/dm.c b/drivers/md/dm.c index e66f4040d84b..d9206a3ebe5a 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -21,6 +21,7 @@ #include <linux/delay.h> #include <linux/wait.h> #include <linux/pr.h> +#include <linux/vmalloc.h> #define DM_MSG_PREFIX "core" @@ -1511,7 +1512,7 @@ static struct mapped_device *alloc_dev(int minor) struct mapped_device *md; void *old_md; - md = kzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id); + md = vzalloc_node(sizeof(*md), numa_node_id); if (!md) { DMWARN("unable to allocate device, out of memory."); return NULL; @@ -1605,7 +1606,7 @@ bad_io_barrier: bad_minor: module_put(THIS_MODULE); bad_module_get: - kfree(md); + kvfree(md); return NULL; } @@ -1624,7 +1625,7 @@ static void free_dev(struct mapped_device *md) free_minor(minor); module_put(THIS_MODULE); - kfree(md); + kvfree(md); } static void __bind_mempools(struct mapped_device *md, struct dm_table *t) |