1
0
mirror of https://gitlab.com/libvirt/libvirt.git synced 2025-03-07 17:28:15 +00:00

Expand docs for timer tick policy

This commit is contained in:
Daniel P. Berrange 2012-03-26 13:29:41 +01:00
parent bd6b0a052e
commit 05e981df2d

View File

@ -1016,11 +1016,32 @@
</dd>
<dt><code>tickpolicy</code></dt>
<dd>
The <code>tickpolicy</code> attribute determines how
missed ticks in the guest are handled, and can be "delay",
"catchup", "merge", or "discard". If the policy is
"catchup", there can be further details in
the <code>catchup</code> sub-element.
<p>
The <code>tickpolicy</code> attribute determines what
happens whens QEMU misses a deadline for injecting a
tick to the guest:
</p>
<dl>
<dt><code>delay</code></dt>
<dd>Continue to deliver ticks at the normal rate.
The guest time will be delayed due to the late
tick</dd>
<dt><code>catchup</code></dt>
<dd>Deliver ticks at a higher rate to catch up
with the missed tick. The guest time should
not be delayed once catchup is complete.</dd>
<dt><code>merge</code></dt>
<dd>Merge the missed tick(s) into one tick and
inject. The guest time may be delayed, depending
on how the OS reacts to the merging of ticks</dd>
<dt><code>discard</code></dt>
<dd>Throw away the missed tick(s) and continue
with future injection normally. The guest time
may be delayed, unless the OS has explicit
handling of lost ticks</dd>
</dl>
<p>If the policy is "catchup", there can be further details in
the <code>catchup</code> sub-element.</p>
<dl>
<dt><code>catchup</code></dt>
<dd>
@ -1030,6 +1051,9 @@
and <code>limit</code>.
</dd>
</dl>
<p>
Note that hypervisors are not required to support all policies across all time sources
</p>
</dd>
<dt><code>frequency</code></dt>
<dd>