Commit 34b48db6 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

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: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent c2661b80

block/blk-settings.c

+1 −3
Original line number Original line Diff line number Diff line
@@ -257,9 +257,7 @@ void blk_limits_max_hw_sectors(struct queue_limits *limits, unsigned int max_hw_ 
		       __func__, max_hw_sectors);

		       __func__, max_hw_sectors);

	}

	}





	limits->max_hw_sectors = max_hw_sectors;

	limits->max_sectors = limits->max_hw_sectors = max_hw_sectors;

	limits->max_sectors = min_t(unsigned int, max_hw_sectors,

				    BLK_DEF_MAX_SECTORS);

}

}

EXPORT_SYMBOL(blk_limits_max_hw_sectors);

EXPORT_SYMBOL(blk_limits_max_hw_sectors);

drivers/block/aoe/aoeblk.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -395,7 +395,7 @@ aoeblk_gdalloc(void *vp) 
	WARN_ON(d->flags & DEVFL_TKILL);

	WARN_ON(d->flags & DEVFL_TKILL);

	WARN_ON(d->gd);

	WARN_ON(d->gd);

	WARN_ON(d->flags & DEVFL_UP);

	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.name = "aoe";

	q->backing_dev_info.ra_pages = READ_AHEAD / PAGE_CACHE_SIZE;

	q->backing_dev_info.ra_pages = READ_AHEAD / PAGE_CACHE_SIZE;

	d->bufpool = mp;

	d->bufpool = mp;

include/linux/blkdev.h

+0 −1
Original line number Original line Diff line number Diff line
@@ -1186,7 +1186,6 @@ extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); 
enum blk_default_limits {

enum blk_default_limits {

	BLK_MAX_SEGMENTS	= 128,

	BLK_MAX_SEGMENTS	= 128,

	BLK_SAFE_MAX_SECTORS	= 255,

	BLK_SAFE_MAX_SECTORS	= 255,

	BLK_DEF_MAX_SECTORS	= 1024,

	BLK_MAX_SEGMENT_SIZE	= 65536,

	BLK_MAX_SEGMENT_SIZE	= 65536,

	BLK_SEG_BOUNDARY_MASK	= 0xFFFFFFFFUL,

	BLK_SEG_BOUNDARY_MASK	= 0xFFFFFFFFUL,

};

};

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