Messages in this thread Patch in this message | | | From | Bob Liu <> | Subject | [PATCH] xen/blkfront: increase the default value of xen_blkif_max_segments | Date | Tue, 16 Dec 2014 18:11:36 +0800 |
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The default maximum value of segments in indirect requests was 32, IO operations with bigger block size(>32*4k) would be split and performance start to drop.
Nowadays backend device usually support 512k max_sectors_kb on desktop, and may larger on server machines with high-end storage system. The default size 128k was not very appropriate, this patch increases the default maximum value to 128(128*4k=512k).
Signed-off-by: Bob Liu <bob.liu@oracle.com> --- drivers/block/xen-blkfront.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 2236c6f..1bf2429 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -94,9 +94,9 @@ static const struct block_device_operations xlvbd_block_fops; * by the backend driver. */ -static unsigned int xen_blkif_max_segments = 32; +static unsigned int xen_blkif_max_segments = 128; module_param_named(max, xen_blkif_max_segments, int, S_IRUGO); -MODULE_PARM_DESC(max, "Maximum amount of segments in indirect requests (default is 32)"); +MODULE_PARM_DESC(max, "Maximum amount of segments in indirect requests (default is 128)"); #define BLK_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE) -- 1.7.10.4
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