Roger Pau Monne
2013-Jun-21 10:56 UTC
[PATCH 4/4] xen-blkfront: increase the default number of indirect segments
When using certain storage devices (like RAID) having a bigger number of segments per request provides better performance. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reported-by: Steven Haigh <netwiz@crc.id.au> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- drivers/block/xen-blkfront.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 2e1ee34..4e3ab34 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 = 64; 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 64)"); #define BLK_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE) -- 1.7.7.5 (Apple Git-26) _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Jan Beulich
2013-Jun-21 11:49 UTC
Re: [PATCH 4/4] xen-blkfront: increase the default number of indirect segments
>>> On 21.06.13 at 12:56, Roger Pau Monne <roger.pau@citrix.com> wrote: > When using certain storage devices (like RAID) having a bigger number > of segments per request provides better performance.And there's no drawback (higher memory foot print if nothing else) on "certain other storage devices"? Adjusting defaults just because it is beneficial for some devices, but may adversely affect others is not really a good thing - in such an event, you'd be better off determining the default dynamically per device. Jan> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> > Reported-by: Steven Haigh <netwiz@crc.id.au> > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > --- > drivers/block/xen-blkfront.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c > index 2e1ee34..4e3ab34 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 = 64; > 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 64)"); > > #define BLK_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE) > > -- > 1.7.7.5 (Apple Git-26) > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel_______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel