block: remove artifical max_hw_sectors cap
Set max_sectors to the value the drivers provides as hardware limit by
default. Linux had proper I/O throttling for a long time and doesn't
rely on a artifically small maximum I/O size anymore. By not limiting
the I/O size by default we remove an annoying tuning step required for
most Linux installation.
Note that both the user, and if absolutely required the driver can still
impose a limit for FS requests below max_hw_sectors_kb.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-settings.c b/block/blk-settings.c
index aa02247..6ed2cbe 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -257,9 +257,7 @@
__func__, max_hw_sectors);
}
- limits->max_hw_sectors = max_hw_sectors;
- limits->max_sectors = min_t(unsigned int, max_hw_sectors,
- BLK_DEF_MAX_SECTORS);
+ limits->max_sectors = limits->max_hw_sectors = max_hw_sectors;
}
EXPORT_SYMBOL(blk_limits_max_hw_sectors);
diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c
index dd73e1f..46c282f 100644
--- a/drivers/block/aoe/aoeblk.c
+++ b/drivers/block/aoe/aoeblk.c
@@ -395,7 +395,7 @@
WARN_ON(d->flags & DEVFL_TKILL);
WARN_ON(d->gd);
WARN_ON(d->flags & DEVFL_UP);
- blk_queue_max_hw_sectors(q, BLK_DEF_MAX_SECTORS);
+ blk_queue_max_hw_sectors(q, 1024);
q->backing_dev_info.name = "aoe";
q->backing_dev_info.ra_pages = READ_AHEAD / PAGE_CACHE_SIZE;
d->bufpool = mp;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 0207a78..74d14db 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1186,7 +1186,6 @@
enum blk_default_limits {
BLK_MAX_SEGMENTS = 128,
BLK_SAFE_MAX_SECTORS = 255,
- BLK_DEF_MAX_SECTORS = 1024,
BLK_MAX_SEGMENT_SIZE = 65536,
BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
};