[libvirt] [PATCH 3/8] Implement virDomain{Set, Get}BlockIoTune for the qemu driver

[Adam Litke]

On Wed, Nov 23, 2011 at 10:41:32AM -0700, Eric Blake wrote:

> Hmm - passing nparams==1 to set just read_bytes_sec has the side effect
> of wiping out any existing total_iops_sec, even though those two
> parameters seem somewhat orthogonal, all because we zero-initialized the
> struct that we pass on to the monitor command.  Is that intended?  I can
> live with it (but it probably ought to be documented), but we may want
> to consider being more flexible, by using '0' to clear a previous limit,
> but initializing to '-1' to imply the limit does not change.  Then the
> qemu_monitor_json code should only emit the arguments that are actually
> being changed, rather than blindly always outputting 6 parameters even
> when the user only passed in one parameter.  But I'm okay delaying that
> to a separate patch based on whether others think it would be a good
> improvement.

+1.  I believe I had pointed this out previously as well (albeit not as
concisely as this).


-- 
Adam Litke <agl at us.ibm.com>
IBM Linux Technology Center