qapi: Craft the dirty-limit capability comment
Signed-off-by: Hyman Huang(黄勇) <yong.huang@smartx.com>
Message-ID: <169073570563.19893.2928364761104733482-2@git.sr.ht>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
diff --git a/qapi/migration.json b/qapi/migration.json
index dffa60f..8843e74 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -519,14 +519,11 @@
# are present. 'return-path' capability must be enabled to use
# it. (since 8.1)
#
-# @dirty-limit: If enabled, migration will use the dirty-limit
-# algorithim to throttle down guest instead of auto-converge
-# algorithim. Throttle algorithim only works when vCPU's dirtyrate
-# greater than 'vcpu-dirty-limit', read processes in guest os
-# aren't penalized any more, so this algorithim can improve
-# performance of vCPU during live migration. This is an optional
-# performance feature and should not affect the correctness of the
-# existing auto-converge algorithim. (Since 8.1)
+# @dirty-limit: If enabled, migration will throttle vCPUs as needed to
+# keep their dirty page rate within @vcpu-dirty-limit. This can
+# improve responsiveness of large guests during live migration,
+# and can result in more stable read performance. Requires KVM
+# with accelerator property "dirty-ring-size" set. (Since 8.1)
#
# Features:
#
