diff options
| -rw-r--r-- | block/blk-settings.c | 1 | ||||
| -rw-r--r-- | block/blk-sysfs.c | 1 | ||||
| -rw-r--r-- | include/linux/backing-dev-defs.h | 1 | ||||
| -rw-r--r-- | mm/readahead.c | 39 |
4 files changed, 31 insertions, 11 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c index f679ae122843..65f16cf4f850 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -249,6 +249,7 @@ void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_secto max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors); max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS); limits->max_sectors = max_sectors; + q->backing_dev_info.io_pages = max_sectors >> (PAGE_SHIFT - 9); } EXPORT_SYMBOL(blk_queue_max_hw_sectors); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 9cc8d7c5439a..ea374e820775 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -212,6 +212,7 @@ queue_max_sectors_store(struct request_queue *q, const char *page, size_t count) spin_lock_irq(q->queue_lock); q->limits.max_sectors = max_sectors_kb << 1; + q->backing_dev_info.io_pages = max_sectors_kb >> (PAGE_SHIFT - 10); spin_unlock_irq(q->queue_lock); return ret; diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index c357f27d5483..b8144b2d59ce 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -136,6 +136,7 @@ struct bdi_writeback { struct backing_dev_info { struct list_head bdi_list; unsigned long ra_pages; /* max readahead in PAGE_SIZE units */ + unsigned long io_pages; /* max allowed IO size */ unsigned int capabilities; /* Device capabilities */ congested_fn *congested_fn; /* Function pointer if device is md/dm */ void *congested_data; /* Pointer to aux data for congested func */ diff --git a/mm/readahead.c b/mm/readahead.c index c8a955b1297e..c4ca70239233 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -207,12 +207,21 @@ out: * memory at once. */ int force_page_cache_readahead(struct address_space *mapping, struct file *filp, - pgoff_t offset, unsigned long nr_to_read) + pgoff_t offset, unsigned long nr_to_read) { + struct backing_dev_info *bdi = inode_to_bdi(mapping->host); + struct file_ra_state *ra = &filp->f_ra; + unsigned long max_pages; + if (unlikely(!mapping->a_ops->readpage && !mapping->a_ops->readpages)) return -EINVAL; - nr_to_read = min(nr_to_read, inode_to_bdi(mapping->host)->ra_pages); + /* + * If the request exceeds the readahead window, allow the read to + * be up to the optimal hardware IO size + */ + max_pages = max_t(unsigned long, bdi->io_pages, ra->ra_pages); + nr_to_read = min(nr_to_read, max_pages); while (nr_to_read) { int err; @@ -369,10 +378,18 @@ ondemand_readahead(struct address_space *mapping, bool hit_readahead_marker, pgoff_t offset, unsigned long req_size) { - unsigned long max = ra->ra_pages; + struct backing_dev_info *bdi = inode_to_bdi(mapping->host); + unsigned long max_pages = ra->ra_pages; pgoff_t prev_offset; /* + * If the request exceeds the readahead window, allow the read to + * be up to the optimal hardware IO size + */ + if (req_size > max_pages && bdi->io_pages > max_pages) + max_pages = min(req_size, bdi->io_pages); + + /* * start of file */ if (!offset) @@ -385,7 +402,7 @@ ondemand_readahead(struct address_space *mapping, if ((offset == (ra->start + ra->size - ra->async_size) || offset == (ra->start + ra->size))) { ra->start += ra->size; - ra->size = get_next_ra_size(ra, max); + ra->size = get_next_ra_size(ra, max_pages); ra->async_size = ra->size; goto readit; } @@ -400,16 +417,16 @@ ondemand_readahead(struct address_space *mapping, pgoff_t start; rcu_read_lock(); - start = page_cache_next_hole(mapping, offset + 1, max); + start = page_cache_next_hole(mapping, offset + 1, max_pages); rcu_read_unlock(); - if (!start || start - offset > max) + if (!start || start - offset > max_pages) return 0; ra->start = start; ra->size = start - offset; /* old async_size */ ra->size += req_size; - ra->size = get_next_ra_size(ra, max); + ra->size = get_next_ra_size(ra, max_pages); ra->async_size = ra->size; goto readit; } @@ -417,7 +434,7 @@ ondemand_readahead(struct address_space *mapping, /* * oversize read */ - if (req_size > max) + if (req_size > max_pages) goto initial_readahead; /* @@ -433,7 +450,7 @@ ondemand_readahead(struct address_space *mapping, * Query the page cache and look for the traces(cached history pages) * that a sequential stream would leave behind. */ - if (try_context_readahead(mapping, ra, offset, req_size, max)) + if (try_context_readahead(mapping, ra, offset, req_size, max_pages)) goto readit; /* @@ -444,7 +461,7 @@ ondemand_readahead(struct address_space *mapping, initial_readahead: ra->start = offset; - ra->size = get_init_ra_size(req_size, max); + ra->size = get_init_ra_size(req_size, max_pages); ra->async_size = ra->size > req_size ? ra->size - req_size : ra->size; readit: @@ -454,7 +471,7 @@ readit: * the resulted next readahead window into the current one. */ if (offset == ra->start && ra->size == ra->async_size) { - ra->async_size = get_next_ra_size(ra, max); + ra->async_size = get_next_ra_size(ra, max_pages); ra->size += ra->async_size; } |