diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-block | 37 | ||||
| -rw-r--r-- | block/Kconfig | 11 | ||||
| -rw-r--r-- | block/blk-settings.c | 77 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 1 |
4 files changed, 77 insertions, 49 deletions
diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block index cbbd3e0..5f3beda 100644 --- a/Documentation/ABI/testing/sysfs-block +++ b/Documentation/ABI/testing/sysfs-block @@ -94,28 +94,37 @@ What: /sys/block/<disk>/queue/physical_block_size Date: May 2009 Contact: Martin K. Petersen <martin.petersen@oracle.com> Description: - This is the smallest unit the storage device can write - without resorting to read-modify-write operation. It is - usually the same as the logical block size but may be - bigger. One example is SATA drives with 4KB sectors - that expose a 512-byte logical block size to the - operating system. + This is the smallest unit a physical storage device can + write atomically. It is usually the same as the logical + block size but may be bigger. One example is SATA + drives with 4KB sectors that expose a 512-byte logical + block size to the operating system. For stacked block + devices the physical_block_size variable contains the + maximum physical_block_size of the component devices. What: /sys/block/<disk>/queue/minimum_io_size Date: April 2009 Contact: Martin K. Petersen <martin.petersen@oracle.com> Description: - Storage devices may report a preferred minimum I/O size, - which is the smallest request the device can perform - without incurring a read-modify-write penalty. For disk - drives this is often the physical block size. For RAID - arrays it is often the stripe chunk size. + 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. What: /sys/block/<disk>/queue/optimal_io_size Date: April 2009 Contact: Martin K. Petersen <martin.petersen@oracle.com> Description: Storage devices may report an optimal I/O size, which is - the device's preferred unit of receiving I/O. This is - rarely reported for disk drives. For RAID devices it is - usually the stripe width or the internal block size. + 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. If no optimal I/O size is + reported this file contains 0. diff --git a/block/Kconfig b/block/Kconfig index 95a86ad..9be0b56 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -48,9 +48,9 @@ config LBDAF If unsure, say Y. config BLK_DEV_BSG - bool "Block layer SG support v4 (EXPERIMENTAL)" - depends on EXPERIMENTAL - ---help--- + bool "Block layer SG support v4" + default y + help Saying Y here will enable generic SG (SCSI generic) v4 support for any block device. @@ -60,7 +60,10 @@ config BLK_DEV_BSG protocols (e.g. Task Management Functions and SMP in Serial Attached SCSI). - If unsure, say N. + This option is required by recent UDEV versions to properly + access device serial numbers, etc. + + If unsure, say Y. config BLK_DEV_INTEGRITY bool "Block layer data integrity support" diff --git a/block/blk-settings.c b/block/blk-settings.c index 8a3ea3b..476d870 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -7,6 +7,7 @@ #include <linux/bio.h> #include <linux/blkdev.h> #include <linux/bootmem.h> /* for max_pfn/max_low_pfn */ +#include <linux/gcd.h> #include "blk.h" @@ -384,8 +385,8 @@ void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset) EXPORT_SYMBOL(blk_queue_alignment_offset); /** - * blk_queue_io_min - set minimum request size for the queue - * @q: the request queue for the device + * blk_limits_io_min - set minimum request size for a device + * @limits: the queue limits * @min: smallest I/O size in bytes * * Description: @@ -394,15 +395,35 @@ EXPORT_SYMBOL(blk_queue_alignment_offset); * smallest I/O the device can perform without incurring a performance * penalty. */ -void blk_queue_io_min(struct request_queue *q, unsigned int min) +void blk_limits_io_min(struct queue_limits *limits, unsigned int min) { - q->limits.io_min = min; + limits->io_min = min; - if (q->limits.io_min < q->limits.logical_block_size) - q->limits.io_min = q->limits.logical_block_size; + if (limits->io_min < limits->logical_block_size) + limits->io_min = limits->logical_block_size; - if (q->limits.io_min < q->limits.physical_block_size) - q->limits.io_min = q->limits.physical_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 + * @min: smallest I/O size in bytes + * + * Description: + * 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) +{ + blk_limits_io_min(&q->limits, min); } EXPORT_SYMBOL(blk_queue_io_min); @@ -412,8 +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) { @@ -433,27 +458,7 @@ 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); @@ -523,6 +528,16 @@ 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); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index e7cb5db..69103e0 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -913,6 +913,7 @@ extern void blk_queue_logical_block_size(struct request_queue *, unsigned short) extern void blk_queue_physical_block_size(struct request_queue *, unsigned short); extern void blk_queue_alignment_offset(struct request_queue *q, unsigned int alignment); +extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); extern void blk_queue_io_min(struct request_queue *q, unsigned int min); extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); extern void blk_set_default_limits(struct queue_limits *lim); |
