From c77a5710b7e23847bfdb81fcaa10b585f65c960a Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Wed, 10 Mar 2010 00:48:33 -0500 Subject: block: Export max number of segments and max segment size in sysfs These two values are useful when debugging issues surrounding maximum I/O size. Put them in sysfs with the rest of the queue limits. Signed-off-by: Martin K. Petersen Signed-off-by: Jens Axboe --- block/blk-sysfs.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'block') diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index e85442415db3..fad86550255a 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -106,6 +106,19 @@ static ssize_t queue_max_sectors_show(struct request_queue *q, char *page) return queue_var_show(max_sectors_kb, (page)); } +static ssize_t queue_max_segments_show(struct request_queue *q, char *page) +{ + return queue_var_show(queue_max_segments(q), (page)); +} + +static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page) +{ + if (test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags)) + return queue_var_show(queue_max_segment_size(q), (page)); + + return queue_var_show(PAGE_CACHE_SIZE, (page)); +} + static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page) { return queue_var_show(queue_logical_block_size(q), page); @@ -280,6 +293,16 @@ static struct queue_sysfs_entry queue_max_hw_sectors_entry = { .show = queue_max_hw_sectors_show, }; +static struct queue_sysfs_entry queue_max_segments_entry = { + .attr = {.name = "max_segments", .mode = S_IRUGO }, + .show = queue_max_segments_show, +}; + +static struct queue_sysfs_entry queue_max_segment_size_entry = { + .attr = {.name = "max_segment_size", .mode = S_IRUGO }, + .show = queue_max_segment_size_show, +}; + static struct queue_sysfs_entry queue_iosched_entry = { .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR }, .show = elv_iosched_show, @@ -355,6 +378,8 @@ static struct attribute *default_attrs[] = { &queue_ra_entry.attr, &queue_max_hw_sectors_entry.attr, &queue_max_sectors_entry.attr, + &queue_max_segments_entry.attr, + &queue_max_segment_size_entry.attr, &queue_iosched_entry.attr, &queue_hw_sector_size_entry.attr, &queue_logical_block_size_entry.attr, -- cgit v1.2.1