linux-stable/include/linux/ceph/msgpool.h

#ifndef _FS_CEPH_MSGPOOL
#define _FS_CEPH_MSGPOOL

#include <linux/mempool.h>

/*
 * we use memory pools for preallocating messages we may receive, to
 * avoid unexpected OOM conditions.
 */
struct ceph_msgpool {
	const char *name;
	mempool_t *pool;
	int type;               /* preallocated message type */
	int front_len;          /* preallocated payload size */
};

extern int ceph_msgpool_init(struct ceph_msgpool *pool, int type,
			     int front_len, int size, bool blocking,
			     const char *name);
extern void ceph_msgpool_destroy(struct ceph_msgpool *pool);
extern struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *,
					 int front_len);
extern void ceph_msgpool_put(struct ceph_msgpool *, struct ceph_msg *);

#endif
ceph: message pools The msgpool is a basic mempool_t-like structure to preallocate messages we expect to receive over the wire. This ensures we have the necessary memory preallocated to process replies to requests, or to process unsolicited messages from various servers. Signed-off-by: Sage Weil <sage@newdream.net> 2009-10-06 18:31:13 +00:00			`#ifndef _FS_CEPH_MSGPOOL`
			`#define _FS_CEPH_MSGPOOL`

ceph: rewrite msgpool using mempool_t Since we don't need to maintain large pools of messages, we can just use the standard mempool_t. We maintain a msgpool 'wrapper' because we need the mempool_t* in the alloc function, and mempool gives us only pool_data. Signed-off-by: Sage Weil <sage@newdream.net> 2010-04-01 22:23:14 +00:00			`#include <linux/mempool.h>`
ceph: message pools The msgpool is a basic mempool_t-like structure to preallocate messages we expect to receive over the wire. This ensures we have the necessary memory preallocated to process replies to requests, or to process unsolicited messages from various servers. Signed-off-by: Sage Weil <sage@newdream.net> 2009-10-06 18:31:13 +00:00
			`/*`
			`* we use memory pools for preallocating messages we may receive, to`
			`* avoid unexpected OOM conditions.`
			`*/`
			`struct ceph_msgpool {`
ceph: name msgpools; useful error messages Signed-off-by: Sage Weil <sage@newdream.net> 2010-04-24 16:56:35 +00:00			`const char *name;`
ceph: rewrite msgpool using mempool_t Since we don't need to maintain large pools of messages, we can just use the standard mempool_t. We maintain a msgpool 'wrapper' because we need the mempool_t* in the alloc function, and mempool gives us only pool_data. Signed-off-by: Sage Weil <sage@newdream.net> 2010-04-01 22:23:14 +00:00			`mempool_t *pool;`
libceph: initialize msgpool message types Initialize the type field for messages in a msgpool. The caller was doing this for osd ops, but not for the reply messages. Reported-by: Alex Elder <elder@inktank.com> Signed-off-by: Sage Weil <sage@inktank.com> 2012-07-09 21:22:34 +00:00			`int type; /* preallocated message type */`
ceph: message pools The msgpool is a basic mempool_t-like structure to preallocate messages we expect to receive over the wire. This ensures we have the necessary memory preallocated to process replies to requests, or to process unsolicited messages from various servers. Signed-off-by: Sage Weil <sage@newdream.net> 2009-10-06 18:31:13 +00:00			`int front_len; /* preallocated payload size */`
			`};`

libceph: initialize msgpool message types Initialize the type field for messages in a msgpool. The caller was doing this for osd ops, but not for the reply messages. Reported-by: Alex Elder <elder@inktank.com> Signed-off-by: Sage Weil <sage@inktank.com> 2012-07-09 21:22:34 +00:00			`extern int ceph_msgpool_init(struct ceph_msgpool *pool, int type,`
ceph: name msgpools; useful error messages Signed-off-by: Sage Weil <sage@newdream.net> 2010-04-24 16:56:35 +00:00			`int front_len, int size, bool blocking,`
			`const char *name);`
ceph: message pools The msgpool is a basic mempool_t-like structure to preallocate messages we expect to receive over the wire. This ensures we have the necessary memory preallocated to process replies to requests, or to process unsolicited messages from various servers. Signed-off-by: Sage Weil <sage@newdream.net> 2009-10-06 18:31:13 +00:00			`extern void ceph_msgpool_destroy(struct ceph_msgpool *pool);`
ceph: warn on allocation from msgpool with larger front_len Pass the front_len we need when pulling a message off a msgpool, and WARN if it is greater than the pool's size. Then try to allocate a new message (to continue without failing). Signed-off-by: Sage Weil <sage@newdream.net> 2009-10-15 00:36:07 +00:00			`extern struct ceph_msg ceph_msgpool_get(struct ceph_msgpool ,`
			`int front_len);`
ceph: message pools The msgpool is a basic mempool_t-like structure to preallocate messages we expect to receive over the wire. This ensures we have the necessary memory preallocated to process replies to requests, or to process unsolicited messages from various servers. Signed-off-by: Sage Weil <sage@newdream.net> 2009-10-06 18:31:13 +00:00			`extern void ceph_msgpool_put(struct ceph_msgpool , struct ceph_msg );`

			`#endif`