mars/kernel/mars_buf.h

100 lines
2.3 KiB
C

// (c) 2010 Thomas Schoebel-Theuer / 1&1 Internet AG
#ifndef MARS_BUF_H
#define MARS_BUF_H
#include <linux/list.h>
#include <asm/atomic.h>
//#define MARS_BUF_HASH_MAX 512
#define MARS_BUF_HASH_MAX 2048
#define LIST_FREE 0
#define LIST_FORGET 1
#define LIST_LRU 2
#define LIST_MAX 3
struct buf_mref_aspect {
GENERIC_ASPECT(mref);
struct buf_head *rfa_bf;
//struct list_head rfa_bf_head;
struct list_head rfa_pending_head;
//struct list_head tmp_head;
};
struct cache_anchor {
spinlock_t hash_lock;
struct list_head hash_anchor;
};
struct buf_brick {
MARS_BRICK(buf);
/* brick parameters */
int backing_order;
int backing_size;
int max_count;
bool optimize_chains;
/* internals */
spinlock_t brick_lock;
atomic_t alloc_count;
atomic_t list_count[LIST_MAX];
atomic_t hashed_count;
atomic_t nr_io_pending;
atomic_t nr_collisions;
struct mars_info base_info;
bool got_info;
// lists for caching
struct list_head list_anchor[LIST_MAX]; // members are hashed and not in use
struct list_head forget_anchor; // like lru_anchor, but likely
struct cache_anchor cache_anchors[MARS_BUF_HASH_MAX]; // hash table
// statistics
unsigned long last_jiffies;
atomic_t hit_count;
atomic_t miss_count;
atomic_t opt_count;
atomic_t chain_count;
atomic_t post_count;
atomic_t write_count;
atomic_t io_count;
};
struct buf_input {
MARS_INPUT(buf);
};
struct buf_output {
MARS_OUTPUT(buf);
};
MARS_TYPES(buf);
struct buf_head {
void *bf_data; // this MUST come first
spinlock_t bf_lock;
struct buf_brick *bf_brick;
loff_t bf_pos;
loff_t bf_base_index;
int bf_flags;
int bf_error;
atomic_t bf_hash_count; // # references pinning the hash
atomic_t bf_mref_count; // # mrefs (only used for checking, no real semantics)
atomic_t bf_io_count; // # IOs in flight
// statistics / data for strategic decisions
atomic_t bf_mfu_stat;
atomic_t bf_chain_len;
bool bf_chain_detected;
// lists for caching
//struct list_head bf_mref_anchor; // all current mref members
struct list_head bf_list_head;
struct list_head bf_hash_head;
unsigned long bf_jiffies;
int bf_member;
// lists for IO
struct list_head bf_io_pending_anchor;
struct list_head bf_postpone_anchor;
};
#endif