flamegraphs: Move demo of flamegraph earlier

[libguestfs-talks.git] / 2019-kvm-forum / 8300-tradeoff-poll-v-notify.html

diff --git a/2019-kvm-forum/8300-tradeoff-poll-v-notify.html b/2019-kvm-forum/8300-tradeoff-poll-v-notify.html
index 8e9f729..3ed0051 100644 (file)
--- a/2019-kvm-forum/8300-tradeoff-poll-v-notify.html
+++ b/2019-kvm-forum/8300-tradeoff-poll-v-notify.html
@@ -5,22 +5,24 @@
 <h1>Tradeoff: poll or notify</h1>
 
 <p>
-  Filler - need to demonstrate:
+  Polling:
+  <ul>
+    <li>Server cannot report size unless client asks
+    <li>Each server reply sets <code>NBD_REPLY_DONE</code> flag bit
+    <li>Client must ask in a loop when polling for a change from the
+      server
+  </ul>
+<p>
+  <img src="8300-poll.png"/>
 
 <p>
-  polling (server cannot tell client about async changes unless client
-  polls):
-  <br>client: NBD_CMD_RESIZE(0)
-  <br>server: NBD_REPLY_TYPE_RESIZE response, including NBD_REPLY_DONE
-  <br>do stuff
-  <br>client: NBD_CMD_RESIZE(0)
-  <br>server: NBD_REPLY_TYPE_RESIZE response, including NBD_REPLY_DONE
+  Notify:
+  <ul>
+    <li>Client uses <code>NBD_CMD_FLAG_RESIZE_NOTIFY</code> to
+      request an open-ended command
+    <li>Server replies with <code>NBD_REPLY_DONE</code> flag clear
+      whenever it has a new size to report
+  </ul>
 <p>
-  notify (client registers open-ended command to allow multiple async
-  server responses as needed):
-  <br>client: NBD_CMD_RESIZE(NBD_CMD_FLAG_NOTIFY)
-  <br>do stuff
-  <br>server: NBD_REPLY_TYPE_RESIZE response, excluding NBD_REPLY_DONE
-  <br>do stuff
-  <br>server: NBD_REPLY_TYPE_RESIZE response, excluding NBD_REPLY_DONE
+  <img src="8300-notify.png"/>
 </p>