diff options
Diffstat (limited to 'fs/xfs/pagebuf/page_buf.c')
| -rw-r--r-- | fs/xfs/pagebuf/page_buf.c | 78 |
1 files changed, 54 insertions, 24 deletions
diff --git a/fs/xfs/pagebuf/page_buf.c b/fs/xfs/pagebuf/page_buf.c index 5663f6d4b4..05e086ad25 100644 --- a/fs/xfs/pagebuf/page_buf.c +++ b/fs/xfs/pagebuf/page_buf.c @@ -119,9 +119,9 @@ pb_trace_func( STATIC kmem_cache_t *pagebuf_cache; STATIC void pagebuf_daemon_wakeup(int); +STATIC void pagebuf_delwri_queue(page_buf_t *, int); STATIC struct workqueue_struct *pagebuf_workqueue; - /* * Pagebuf module configuration parameters, exported via * /proc/sys/vm/pagebuf @@ -155,35 +155,37 @@ struct pbstats pbstats; * Pagebuf hashing */ -#define NBITS 5 -#define NHASH (1<<NBITS) - +/* This structure must be a power of 2 long for the hash to work */ typedef struct { struct list_head pb_hash; int pb_count; spinlock_t pb_hash_lock; } pb_hash_t; -STATIC pb_hash_t pbhash[NHASH]; +static pb_hash_t *pbhash; +static unsigned int pb_hash_mask; +static unsigned int pb_hash_shift; +static unsigned int pb_order; #define pb_hash(pb) &pbhash[pb->pb_hash_index] -STATIC int +/* + * This hash is the same one as used on the Linux buffer cache, + * see fs/buffer.c + */ + +#define _hashfn(dev,block) \ + ((((dev)<<(pb_hash_shift - 6)) ^ ((dev)<<(pb_hash_shift - 9))) ^ \ + (((block)<<(pb_hash_shift - 6)) ^ ((block) >> 13) ^ \ + ((block) << (pb_hash_shift - 12)))) + +static inline int _bhash( dev_t dev, loff_t base) { - int bit, hval; - base >>= 9; - /* - * dev_t is 16 bits, loff_t is always 64 bits - */ - base ^= dev; - for (bit = hval = 0; base != 0 && bit < sizeof(base) * 8; bit += NBITS) { - hval ^= (int)base & (NHASH-1); - base >>= NBITS; - } - return hval; + + return (_hashfn(dev, base) & pb_hash_mask); } /* @@ -1516,7 +1518,7 @@ STATIC int pbd_active = 1; STATIC LIST_HEAD(pbd_delwrite_queue); STATIC spinlock_t pbd_delwrite_lock = SPIN_LOCK_UNLOCKED; -void +STATIC void pagebuf_delwri_queue( page_buf_t *pb, int unlock) @@ -1862,7 +1864,39 @@ pagebuf_shaker(void) int __init pagebuf_init(void) { - int i; + int order, mempages, i; + unsigned int nr_hash; + extern int xfs_physmem; + + mempages = xfs_physmem >>= 16; + mempages *= sizeof(pb_hash_t); + for (order = 0; (1 << order) < mempages; order++) + ; + + if (order > 3) order = 3; /* cap us at 2K buckets */ + + do { + unsigned long tmp; + + nr_hash = (PAGE_SIZE << order) / sizeof(pb_hash_t); + nr_hash = 1 << (ffs(nr_hash) - 1); + pb_hash_mask = (nr_hash - 1); + tmp = nr_hash; + pb_hash_shift = 0; + while((tmp >>= 1UL) != 0UL) + pb_hash_shift++; + + pbhash = (pb_hash_t *) + __get_free_pages(GFP_KERNEL, order); + pb_order = order; + } while (pbhash == NULL && --order > 0); + printk("pagebuf cache hash table entries: %d (order: %d, %ld bytes)\n", + nr_hash, order, (PAGE_SIZE << order)); + + for(i = 0; i < nr_hash; i++) { + spin_lock_init(&pbhash[i].pb_hash_lock); + INIT_LIST_HEAD(&pbhash[i].pb_hash); + } pagebuf_table_header = register_sysctl_table(pagebuf_root_table, 1); @@ -1880,11 +1914,6 @@ pagebuf_init(void) return -ENOMEM; } - for (i = 0; i < NHASH; i++) { - spin_lock_init(&pbhash[i].pb_hash_lock); - INIT_LIST_HEAD(&pbhash[i].pb_hash); - } - #ifdef PAGEBUF_TRACE pb_trace.buf = (pagebuf_trace_t *)kmalloc( PB_TRACE_BUFSIZE * sizeof(pagebuf_trace_t), GFP_KERNEL); @@ -1911,6 +1940,7 @@ pagebuf_terminate(void) kmem_cache_destroy(pagebuf_cache); kmem_shake_deregister(pagebuf_shaker); + free_pages((unsigned long)pbhash, pb_order); unregister_sysctl_table(pagebuf_table_header); #ifdef CONFIG_PROC_FS |