From c23acfac10786ac5062a0615e23e68b913ac8da0 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 6 May 2025 17:47:25 +0530 Subject: [PATCH] block: introduce a write_stream_granularity queue limit Export the granularity that write streams should be discarded with, as it is essential for making good use of them. Reviewed-by: Hannes Reinecke Reviewed-by: Nitesh Shetty Signed-off-by: Christoph Hellwig Signed-off-by: Keith Busch Signed-off-by: Kanchan Joshi Link: https://lore.kernel.org/r/20250506121732.8211-5-joshi.k@samsung.com Signed-off-by: Jens Axboe --- Documentation/ABI/stable/sysfs-block | 8 ++++++++ block/blk-sysfs.c | 3 +++ include/linux/blkdev.h | 1 + 3 files changed, 12 insertions(+) diff --git a/Documentation/ABI/stable/sysfs-block b/Documentation/ABI/stable/sysfs-block index 8bbe1eca28df..4ba771b56b3b 100644 --- a/Documentation/ABI/stable/sysfs-block +++ b/Documentation/ABI/stable/sysfs-block @@ -555,6 +555,14 @@ Description: supported. If supported, valid values are 1 through max_write_streams, inclusive. +What: /sys/block//queue/write_stream_granularity +Date: November 2024 +Contact: linux-block@vger.kernel.org +Description: + [RO] Granularity of a write stream in bytes. The granularity + of a write stream is the size that should be discarded or + overwritten together to avoid write amplification in the device. + What: /sys/block//queue/max_segments Date: March 2010 Contact: linux-block@vger.kernel.org diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 5934150d4204..386374ff655b 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -135,6 +135,7 @@ QUEUE_SYSFS_LIMIT_SHOW(max_discard_segments) QUEUE_SYSFS_LIMIT_SHOW(max_integrity_segments) QUEUE_SYSFS_LIMIT_SHOW(max_segment_size) QUEUE_SYSFS_LIMIT_SHOW(max_write_streams) +QUEUE_SYSFS_LIMIT_SHOW(write_stream_granularity) QUEUE_SYSFS_LIMIT_SHOW(logical_block_size) QUEUE_SYSFS_LIMIT_SHOW(physical_block_size) QUEUE_SYSFS_LIMIT_SHOW(chunk_sectors) @@ -490,6 +491,7 @@ QUEUE_LIM_RO_ENTRY(queue_max_segments, "max_segments"); QUEUE_LIM_RO_ENTRY(queue_max_integrity_segments, "max_integrity_segments"); QUEUE_LIM_RO_ENTRY(queue_max_segment_size, "max_segment_size"); QUEUE_LIM_RO_ENTRY(queue_max_write_streams, "max_write_streams"); +QUEUE_LIM_RO_ENTRY(queue_write_stream_granularity, "write_stream_granularity"); QUEUE_RW_ENTRY(elv_iosched, "scheduler"); QUEUE_LIM_RO_ENTRY(queue_logical_block_size, "logical_block_size"); @@ -645,6 +647,7 @@ static struct attribute *queue_attrs[] = { &queue_max_integrity_segments_entry.attr, &queue_max_segment_size_entry.attr, &queue_max_write_streams_entry.attr, + &queue_write_stream_granularity_entry.attr, &queue_hw_sector_size_entry.attr, &queue_logical_block_size_entry.attr, &queue_physical_block_size_entry.attr, diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 13e1426ad38d..52b7a27c46e8 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -405,6 +405,7 @@ struct queue_limits { unsigned short max_discard_segments; unsigned short max_write_streams; + unsigned int write_stream_granularity; unsigned int max_open_zones; unsigned int max_active_zones; -- 2.50.1