From a4e7d46407d73f35d217013b363b79a8f8eafcaa Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 28 Jul 2009 09:07:29 +0200 Subject: block: always assign default lock to queues Move the assignment of a default lock below blk_init_queue() to blk_queue_make_request(), so we also get to set the default lock for ->make_request_fn() based drivers. This is important since the queue flag locking requires a lock to be in place. Signed-off-by: Jens Axboe --- block/blk-settings.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'block/blk-settings.c') diff --git a/block/blk-settings.c b/block/blk-settings.c index bd582a7f531..8a3ea3bba10 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -164,6 +164,13 @@ void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn) blk_set_default_limits(&q->limits); + /* + * If the caller didn't supply a lock, fall back to our embedded + * per-queue locks + */ + if (!q->queue_lock) + q->queue_lock = &q->__queue_lock; + /* * by default assume old behaviour and bounce for any highmem page */ -- cgit v1.2.3-18-g5258 From fef246672b009cf3f7a74e2fc9a76932ef2eeed2 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Fri, 31 Jul 2009 11:49:10 -0400 Subject: block: Make blk_queue_stack_limits use the new stacking interface blk_queue_stack_limits() has been superceded by blk_stack_limits() and disk_stack_limits(). Wrap the function call for now, we'll deprecate it later. Signed-off-by: Martin K. Petersen Signed-off-by: Jens Axboe --- block/blk-settings.c | 22 +--------------------- 1 file changed, 1 insertion(+), 21 deletions(-) (limited to 'block/blk-settings.c') diff --git a/block/blk-settings.c b/block/blk-settings.c index 8a3ea3bba10..8e86e2d2b14 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -433,27 +433,7 @@ EXPORT_SYMBOL(blk_queue_io_opt); **/ void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b) { - /* zero is "infinity" */ - t->limits.max_sectors = min_not_zero(queue_max_sectors(t), - queue_max_sectors(b)); - - t->limits.max_hw_sectors = min_not_zero(queue_max_hw_sectors(t), - queue_max_hw_sectors(b)); - - t->limits.seg_boundary_mask = min_not_zero(queue_segment_boundary(t), - queue_segment_boundary(b)); - - t->limits.max_phys_segments = min_not_zero(queue_max_phys_segments(t), - queue_max_phys_segments(b)); - - t->limits.max_hw_segments = min_not_zero(queue_max_hw_segments(t), - queue_max_hw_segments(b)); - - t->limits.max_segment_size = min_not_zero(queue_max_segment_size(t), - queue_max_segment_size(b)); - - t->limits.logical_block_size = max(queue_logical_block_size(t), - queue_logical_block_size(b)); + blk_stack_limits(&t->limits, &b->limits, 0); if (!t->queue_lock) WARN_ON_ONCE(1); -- cgit v1.2.3-18-g5258 From 7c958e32649e0c35801762878fb0b6da8c55a515 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Fri, 31 Jul 2009 11:49:11 -0400 Subject: block: Add a wrapper for setting minimum request size without a queue Introduce blk_limits_io_min() and make blk_queue_io_min() call it. Signed-off-by: Mike Snitzer Signed-off-by: Martin K. Petersen Signed-off-by: Jens Axboe --- block/blk-settings.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) (limited to 'block/blk-settings.c') diff --git a/block/blk-settings.c b/block/blk-settings.c index 8e86e2d2b14..1f719743416 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -383,6 +383,29 @@ void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset) } EXPORT_SYMBOL(blk_queue_alignment_offset); +/** + * blk_limits_io_min - set minimum request size for a device + * @limits: the queue limits + * @min: smallest I/O size in bytes + * + * Description: + * Some devices have an internal block size bigger than the reported + * hardware sector size. This function can be used to signal the + * smallest I/O the device can perform without incurring a performance + * penalty. + */ +void blk_limits_io_min(struct queue_limits *limits, unsigned int min) +{ + limits->io_min = min; + + if (limits->io_min < limits->logical_block_size) + limits->io_min = limits->logical_block_size; + + if (limits->io_min < limits->physical_block_size) + limits->io_min = limits->physical_block_size; +} +EXPORT_SYMBOL(blk_limits_io_min); + /** * blk_queue_io_min - set minimum request size for the queue * @q: the request queue for the device @@ -396,13 +419,7 @@ EXPORT_SYMBOL(blk_queue_alignment_offset); */ void blk_queue_io_min(struct request_queue *q, unsigned int min) { - q->limits.io_min = min; - - if (q->limits.io_min < q->limits.logical_block_size) - q->limits.io_min = q->limits.logical_block_size; - - if (q->limits.io_min < q->limits.physical_block_size) - q->limits.io_min = q->limits.physical_block_size; + blk_limits_io_min(&q->limits, min); } EXPORT_SYMBOL(blk_queue_io_min); -- cgit v1.2.3-18-g5258 From 70dd5bf3b99964d52862ad2810c24cc32a553535 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Fri, 31 Jul 2009 11:49:12 -0400 Subject: block: Stack optimal I/O size When stacking block devices ensure that optimal I/O size is scaled accordingly. Signed-off-by: Martin K. Petersen Reviewed-by: Mike Snitzer Signed-off-by: Jens Axboe --- block/blk-settings.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'block/blk-settings.c') diff --git a/block/blk-settings.c b/block/blk-settings.c index 1f719743416..e1327ddfc13 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -7,6 +7,7 @@ #include #include #include /* for max_pfn/max_low_pfn */ +#include #include "blk.h" @@ -520,6 +521,16 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, return -1; } + /* Find lcm() of optimal I/O size */ + if (t->io_opt && b->io_opt) + t->io_opt = (t->io_opt * b->io_opt) / gcd(t->io_opt, b->io_opt); + else if (b->io_opt) + t->io_opt = b->io_opt; + + /* Verify that optimal I/O size is a multiple of io_min */ + if (t->io_min && t->io_opt % t->io_min) + return -1; + return 0; } EXPORT_SYMBOL(blk_stack_limits); -- cgit v1.2.3-18-g5258 From 7e5f5fb09e6fc657f21816b5a18ba645a913368e Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Fri, 31 Jul 2009 11:49:13 -0400 Subject: block: Update topology documentation Update topology comments and sysfs documentation based upon discussions with Neil Brown. Signed-off-by: Martin K. Petersen Signed-off-by: Jens Axboe --- block/blk-settings.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) (limited to 'block/blk-settings.c') diff --git a/block/blk-settings.c b/block/blk-settings.c index e1327ddfc13..476d8706507 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -413,10 +413,13 @@ EXPORT_SYMBOL(blk_limits_io_min); * @min: smallest I/O size in bytes * * Description: - * Some devices have an internal block size bigger than the reported - * hardware sector size. This function can be used to signal the - * smallest I/O the device can perform without incurring a performance - * penalty. + * Storage devices may report a granularity or preferred minimum I/O + * size which is the smallest request the device can perform without + * incurring a performance penalty. For disk drives this is often the + * physical block size. For RAID arrays it is often the stripe chunk + * size. A properly aligned multiple of minimum_io_size is the + * preferred request size for workloads where a high number of I/O + * operations is desired. */ void blk_queue_io_min(struct request_queue *q, unsigned int min) { @@ -430,8 +433,12 @@ EXPORT_SYMBOL(blk_queue_io_min); * @opt: optimal request size in bytes * * Description: - * Drivers can call this function to set the preferred I/O request - * size for devices that report such a value. + * Storage devices may report an optimal I/O size, which is the + * device's preferred unit for sustained I/O. This is rarely reported + * for disk drives. For RAID arrays it is usually the stripe width or + * the internal track size. A properly aligned multiple of + * optimal_io_size is the preferred request size for workloads where + * sustained throughput is desired. */ void blk_queue_io_opt(struct request_queue *q, unsigned int opt) { -- cgit v1.2.3-18-g5258