[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH v3 3/3] cpus-common: implement dirty limit on vCPU

From: Hyman Huang
Subject: Re: [PATCH v3 3/3] cpus-common: implement dirty limit on vCPU
Date: Mon, 22 Nov 2021 16:19:37 +0800
User-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.3.0

在 2021/11/22 15:35, Markus Armbruster 写道:
huangy81@chinatelecom.cn writes:

From: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>

implement dirtyrate calculation periodically basing on
dirty-ring and throttle vCPU until it reachs the quota
dirtyrate given by user.

introduce qmp commands set-dirty-limit/cancel-dirty-limit to
set/cancel dirty limit on vCPU.

Please start sentences with a capital letter.

Ok,i'll check the syntax problem next version.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>


diff --git a/qapi/misc.json b/qapi/misc.json
index 358548a..98e6001 100644
--- a/qapi/misc.json
+++ b/qapi/misc.json
@@ -527,3 +527,42 @@
   'data': { '*option': 'str' },
   'returns': ['CommandLineOptionInfo'],
   'allow-preconfig': true }
+# @set-dirty-limit:
+# This command could be used to cap the vCPU memory load, which is also
+# refered as dirtyrate. One should use "calc-dirty-rate" with "dirty-ring"
+# and to calculate vCPU dirtyrate and query it with "query-dirty-rate".
+# Once getting the vCPU current dirtyrate, "set-dirty-limit" can be used
+# to set the upper limit of dirtyrate for the interested vCPU.

"dirtyrate" is not a word.  Let's spell it "dirty page rate", for
consistency with the documentation in migration.json.
Ok, sounds good.

Regarding "One should use ...": sounds like you have to run
calc-dirty-rate with argument @mode set to @dirty-ring before this
command.  Correct?  What happens when you don't?  set-dirty-limit fails?

Do you also have to run query-dirty-rate before this command?
Actually no, i'll clarify the usage next verison.

Speaking of migration.json: should these commands be defined there, next
to calc-dirty-rate and query-dirty-rate?
I'm struggling too because these commands will be used in migration but it is vCPU they handle.

+# @idx: vCPU index to set dirtylimit.
+# @dirtyrate: upper limit of drityrate the specified vCPU could reach (MB/s)

Typo "drityrate".

Suggest "upper limit for the specified vCPU's dirty page rate (MB/s)".

+# Since: 6.3
+# Example:
+#   {"execute": "set-dirty-limit"}
+#    "arguments": { "idx": 0,
+#                   "dirtyrate": 200 } }
+{ 'command': 'set-dirty-limit',
+  'data': { 'idx': 'int', 'dirtyrate': 'uint64' } }
+# @cancel-dirty-limit:
+# @idx: vCPU index to canceled the dirtylimit
+# Since: 6.3
+# Example:
+#   {"execute": "cancel-dirty-limit"}
+#    "arguments": { "idx": 0 } }
+{ 'command': 'cancel-dirty-limit',
+  'data': { 'idx': 'int' } }
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 1159a64..170ee23 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -3776,5 +3776,6 @@ void qemu_init(int argc, char **argv, char **envp)
+    dirtylimit_setup(current_machine->smp.max_cpus);

Best regard

Hyman Huang(黄勇)

reply via email to

[Prev in Thread] Current Thread [Next in Thread]