From: Keith Busch <kbusch@meta.com>
To: <linux-block@vger.kernel.org>, <axboe@kernel.dk>
Cc: <hch@lst.de>, <ming.lei@redhat.com>, <martin.petersen@oracle.com>,
Keith Busch <kbusch@kernel.org>
Subject: [PATCHv2] block: rename min_segment_size
Date: Mon, 20 Oct 2025 13:47:15 -0700 [thread overview]
Message-ID: <20251020204715.3664483-1-kbusch@meta.com> (raw)
From: Keith Busch <kbusch@kernel.org>
Despite its name, the block layer is fine with segments smaller that the
"min_segment_size" limit. The value is an optimization limit indicating
the largest segment that can be used without considering boundary
limits. Smaller segments can take a fast path, so give it a name that
reflects that: max_fast_segment_size.
Signed-off-by: Keith Busch <kbusch@kernel.org>
---
v1->v2:
Going with "max_fast_segment_size" in this version.
block/blk-merge.c | 2 +-
block/blk-settings.c | 4 ++--
block/blk.h | 2 +-
include/linux/blkdev.h | 2 +-
4 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 37864c5d287ef..c47d18587a0b6 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -336,7 +336,7 @@ int bio_split_io_at(struct bio *bio, const struct queue_limits *lim,
if (nsegs < lim->max_segments &&
bytes + bv.bv_len <= max_bytes &&
- bv.bv_offset + bv.bv_len <= lim->min_segment_size) {
+ bv.bv_offset + bv.bv_len <= lim->max_fast_segment_size) {
nsegs++;
bytes += bv.bv_len;
} else {
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 54cffaae4df49..345b6a271cc35 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -457,12 +457,12 @@ int blk_validate_limits(struct queue_limits *lim)
return -EINVAL;
}
- /* setup min segment size for building new segment in fast path */
+ /* setup max segment size for building new segment in fast path */
if (lim->seg_boundary_mask > lim->max_segment_size - 1)
seg_size = lim->max_segment_size;
else
seg_size = lim->seg_boundary_mask + 1;
- lim->min_segment_size = min_t(unsigned int, seg_size, PAGE_SIZE);
+ lim->max_fast_segment_size = min_t(unsigned int, seg_size, PAGE_SIZE);
/*
* We require drivers to at least do logical block aligned I/O, but
diff --git a/block/blk.h b/block/blk.h
index 170794632135d..32a10024efbaa 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -377,7 +377,7 @@ static inline bool bio_may_need_split(struct bio *bio,
if (bio->bi_vcnt != 1)
return true;
return bio->bi_io_vec->bv_len + bio->bi_io_vec->bv_offset >
- lim->min_segment_size;
+ lim->max_fast_segment_size;
}
/**
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 70b671a9a7f77..99be263b31ab5 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -378,7 +378,7 @@ struct queue_limits {
unsigned int max_sectors;
unsigned int max_user_sectors;
unsigned int max_segment_size;
- unsigned int min_segment_size;
+ unsigned int max_fast_segment_size;
unsigned int physical_block_size;
unsigned int logical_block_size;
unsigned int alignment_offset;
--
2.47.3
next reply other threads:[~2025-10-20 20:47 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-20 20:47 Keith Busch [this message]
2025-10-20 23:28 ` [PATCHv2] block: rename min_segment_size Chaitanya Kulkarni
2025-10-21 1:45 ` Ming Lei
2025-10-21 2:22 ` Martin K. Petersen
2025-10-22 6:11 ` Christoph Hellwig
2025-10-22 13:39 ` Jens Axboe
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