diff -urN linux-2.4.19-pre4/drivers/block/ll_rw_blk.c linux-2.4.19-pre5/drivers/block/ll_rw_blk.c --- linux-2.4.19-pre4/drivers/block/ll_rw_blk.c Fri Mar 29 14:49:08 2002 +++ linux-2.4.19-pre5/drivers/block/ll_rw_blk.c Fri Mar 29 14:49:29 2002 @@ -117,16 +117,6 @@ */ int * max_sectors[MAX_BLKDEV]; -/* - * The total number of requests in each queue. - */ -static int queue_nr_requests; - -/* - * The threshold around which we make wakeup decisions - */ -static int batch_requests; - static inline int get_max_sectors(kdev_t dev) { if (!max_sectors[MAJOR(dev)]) @@ -180,7 +170,7 @@ **/ void blk_cleanup_queue(request_queue_t * q) { - int count = queue_nr_requests; + int count = q->nr_requests; count -= __blk_cleanup_queue(&q->rq[READ]); count -= __blk_cleanup_queue(&q->rq[WRITE]); @@ -330,31 +320,64 @@ spin_unlock_irqrestore(&io_request_lock, flags); } +/** blk_grow_request_list + * @q: The &request_queue_t + * @nr_requests: how many requests are desired + * + * More free requests are added to the queue's free lists, bringing + * the total number of requests to @nr_requests. + * + * The requests are added equally to the request queue's read + * and write freelists. + * + * This function can sleep. + * + * Returns the (new) number of requests which the queue has available. + */ +int blk_grow_request_list(request_queue_t *q, int nr_requests) +{ + spin_lock_irq(&io_request_lock); + while (q->nr_requests < nr_requests) { + struct request *rq; + int rw; + + spin_unlock_irq(&io_request_lock); + rq = kmem_cache_alloc(request_cachep, SLAB_KERNEL); + spin_lock_irq(&io_request_lock); + if (rq == NULL) + break; + memset(rq, 0, sizeof(*rq)); + rq->rq_status = RQ_INACTIVE; + rw = q->nr_requests & 1; + list_add(&rq->queue, &q->rq[rw].free); + q->rq[rw].count++; + q->nr_requests++; + } + q->batch_requests = q->nr_requests / 4; + if (q->batch_requests > 32) + q->batch_requests = 32; + spin_unlock_irq(&io_request_lock); + return q->nr_requests; +} + static void blk_init_free_list(request_queue_t *q) { - struct request *rq; - int i; + struct sysinfo si; + int megs; /* Total memory, in megabytes */ + int nr_requests; INIT_LIST_HEAD(&q->rq[READ].free); INIT_LIST_HEAD(&q->rq[WRITE].free); q->rq[READ].count = 0; q->rq[WRITE].count = 0; + q->nr_requests = 0; - /* - * Divide requests in half between read and write - */ - for (i = 0; i < queue_nr_requests; i++) { - rq = kmem_cache_alloc(request_cachep, SLAB_KERNEL); - if (rq == NULL) { - /* We'll get a `leaked requests' message from blk_cleanup_queue */ - printk(KERN_EMERG "blk_init_free_list: error allocating requests\n"); - break; - } - memset(rq, 0, sizeof(struct request)); - rq->rq_status = RQ_INACTIVE; - list_add(&rq->queue, &q->rq[i&1].free); - q->rq[i&1].count++; - } + si_meminfo(&si); + megs = si.totalram >> (20 - PAGE_SHIFT); + nr_requests = 128; + if (megs < 32) + nr_requests /= 2; + blk_grow_request_list(q, nr_requests); init_waitqueue_head(&q->wait_for_requests[0]); init_waitqueue_head(&q->wait_for_requests[1]); @@ -610,7 +633,7 @@ */ if (q) { list_add(&req->queue, &q->rq[rw].free); - if (++q->rq[rw].count >= batch_requests && + if (++q->rq[rw].count >= q->batch_requests && waitqueue_active(&q->wait_for_requests[rw])) wake_up(&q->wait_for_requests[rw]); } @@ -802,7 +825,7 @@ * See description above __get_request_wait() */ if (rw_ahead) { - if (q->rq[rw].count < batch_requests) { + if (q->rq[rw].count < q->batch_requests) { spin_unlock_irq(&io_request_lock); goto end_io; } @@ -958,6 +981,7 @@ BUG(); set_bit(BH_Req, &bh->b_state); + set_bit(BH_Launder, &bh->b_state); /* * First step, 'identity mapping' - RAID or LVM might @@ -1149,12 +1173,9 @@ blkdev_release_request(req); } -#define MB(kb) ((kb) << 10) - int __init blk_dev_init(void) { struct blk_dev_struct *dev; - int total_ram; request_cachep = kmem_cache_create("blkdev_requests", sizeof(struct request), @@ -1170,22 +1191,6 @@ memset(max_readahead, 0, sizeof(max_readahead)); memset(max_sectors, 0, sizeof(max_sectors)); - total_ram = nr_free_pages() << (PAGE_SHIFT - 10); - - /* - * Free request slots per queue. - * (Half for reads, half for writes) - */ - queue_nr_requests = 64; - if (total_ram > MB(32)) - queue_nr_requests = 128; - - /* - * Batch frees according to queue length - */ - batch_requests = queue_nr_requests/4; - printk("block: %d slots per queue, batch=%d\n", queue_nr_requests, batch_requests); - #ifdef CONFIG_AMIGA_Z2RAM z2_init(); #endif @@ -1296,6 +1301,7 @@ EXPORT_SYMBOL(io_request_lock); EXPORT_SYMBOL(end_that_request_first); EXPORT_SYMBOL(end_that_request_last); +EXPORT_SYMBOL(blk_grow_request_list); EXPORT_SYMBOL(blk_init_queue); EXPORT_SYMBOL(blk_get_queue); EXPORT_SYMBOL(blk_cleanup_queue);