Commit d2be537c authored Aug 13, 2015 by Jeff Moyer Committed by Jens Axboe Aug 18, 2015

block: bump BLK_DEF_MAX_SECTORS to 2560



A value of 2560 (1280k) will accommodate a 10-data-disk stripe
write with chunk size 128k.  In the testing I've done using
iozone, fio, and aio-stress across a number of different storage
devices, a value of 1280 does not show a big performance
difference from 512, but will hopefully help software RAID
setups using SATA disks, as reported by Christoph.

NOTE: drivers/block/aoe/aoeblk.c sets its own max_hw_sectors_kb to
BLK_DEF_MAX_SECTORS.  So, this patch essentially changes aeoblk to
Use a larger maximum sector size, and I did not test this.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

parent 30e2bc08

include/linux/blkdev.h

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -1132,7 +1132,7 @@ 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_DEF_MAX_SECTORS = 2560,
	BLK_MAX_SEGMENT_SIZE = 65536,		BLK_MAX_SEGMENT_SIZE = 65536,
	BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,		BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
	};		};

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