Re: [libvirt] [PATCH] doc: blkio: add some notification

On 07/02/2013 02:44 AM, Gao feng wrote: > If the I/O elevator of disk is not cfq, the setting > of blkio.weight is ineffective. And the setting up > blkio.weight_device will fail. > > Add notification for this situation. > > Signed-off-by: Gao feng <gaofeng(a)cn.fujitsu.com&gt; > --- > docs/formatdomain.html.in | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in > index 47d91ab..8d048be 100644 > --- a/docs/formatdomain.html.in > +++ b/docs/formatdomain.html.in > @@ -740,7 +740,8 @@ > <dd> The optional <code>blkiotune</code> element provides the ability > to tune Blkio cgroup tunable parameters for the domain. If this is > omitted, it defaults to the OS provided > - defaults. <span class="since">Since 0.8.8</span></dd> > + defaults. Notice: blkiotune is effective only when the I/O elevator > + of disk is cfq. <span class="since">Since 0.8.8</span></dd> This is terminology specific to the Linux kernel; would it help to add a phrase explaining that? Maybe something like: Notice: blkiotune is effective only when the host kernel uses the 'cfq' I/O elevator for the disk.

I like the idea of the patch, but am not sure that I know enough about kernel internals to state whether your wording or my alternative is good enough at getting the point across correctly to someone else not very familiar with kernel concepts.