The commit is pushed to "branch-rh9-5.14.0-70.22.1.vz9.17.x-ovz" and will
appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh9-5.14.0-70.22.1.vz9.17.7
------>
commit 3851265540275fe1bb7e3a50d3022d508bcaaf5e
Author: Konstantin Khorenko <khore...@virtuozzo.com>
Date: Mon Oct 17 16:17:02 2022 +0300
FD: balloon: usage information visible by guest: stats reported in OOM/SysRQ
Added info that mem_show() now prints balloon stats, in particular this
covers OOM reports and Alt+SysRQ+m cases.
https://jira.sw.ru/browse/PSBM-142436
Signed-off-by: Konstantin Khorenko <khore...@virtuozzo.com>
Feature: balloon: usage information visible by guest
---
.../balloon-usage_information_visible_by_guest.rst | 95 +++++++++++++++++-----
1 file changed, 76 insertions(+), 19 deletions(-)
diff --git
a/Documentation/Virtuozzo/FeatureDescriptions/balloon-usage_information_visible_by_guest.rst
b/Documentation/Virtuozzo/FeatureDescriptions/balloon-usage_information_visible_by_guest.rst
index 30afdc1acee5..8f476bc8a893 100644
---
a/Documentation/Virtuozzo/FeatureDescriptions/balloon-usage_information_visible_by_guest.rst
+++
b/Documentation/Virtuozzo/FeatureDescriptions/balloon-usage_information_visible_by_guest.rst
@@ -9,38 +9,33 @@ The ballooning mechanism allows VM guests to reduce their
memory size
(thus relinquishing memory to the Host) and to increase it back (thus
taking memory from the Host).
-During OOM guest issues or even just Guet low performance issues
+During OOM guest issues or even just Guest low performance issues
investigations it is important to know if the Host grabs some Guest
memory via ballooning mechanism.
Implementation description:
===========================
-VMware balloon guest file: /sys/kernel/debug/vmmemctl
-Hyper-V balloon guest file: /sys/kernel/debug/hv-balloon
KVM balloon guest file: /sys/kernel/debug/virtio-balloon
+Hyper-V balloon guest file: /sys/kernel/debug/hv-balloon
+VMware balloon guest file: /sys/kernel/debug/vmmemctl
VMware balloon guest file presents for a long time already,
while Hyper-V and KVM balloon guest files were added recently.
-Hyper-V balloon
----------------
-Balloon guest statistics output example::
+The balloon statistics now is also printed by show_mem() function, which
+in particular is called when OOM happens or Alt+SysRQ+m is pressed.
- # cat /sys/kernel/debug/hv-balloon
- host_version : 2.0 // Hyper-V version the Guest is running
under
- capabilities : enabled hot_add
- state : 1 (Initialized)
- page_size : 4096
- pages_added : 0 // pages that are hot_add-ed to the Guest
- pages_onlined : 0 // pages that are added and then put online
- // as available/used
- pages_ballooned_out : 0 // pages the Host have taken back
- vm_pages_commited : 795365 // total pages used by the Guest userspace
- total_pages_commited : 977790 // total pages used by the Guest
user+kernel
- max_dynamic_page_count: 268435456 // maximum pages the Guest can have added
- // via hot_add
+The show_mem() string looks like::
+
+ Balloon InflatedTotal:XXXkB InflatedFree:YYYkB
+
+- Non-zero "InflatedTotal" counter means the provided amount of memory
+ is subtracted from total RAM reported inside the Guest.
+
+- Non-zero "InflatedFree" counter means the provided amount of memory
+ is accounted as "used" inside the Guest.
KVM balloon
-----------
@@ -98,6 +93,68 @@ How to find virtio balloon device among other virtio devices?
- Both "InflatedTotal" and "InflatedFree" cannot be non-zero at the same time.
+Hyper-V balloon
+---------------
+
+Balloon guest statistics output example::
+
+ # cat /sys/kernel/debug/hv-balloon
+ host_version : 2.0 // Hyper-V version the Guest is running
under
+ capabilities : enabled hot_add
+ state : 1 (Initialized)
+ page_size : 4096
+ pages_added : 0 // pages that are hot_add-ed to the Guest
+ pages_onlined : 0 // pages that are added and then put online
+ // as available/used
+ pages_ballooned_out : 0 // pages the Host have taken back
+ vm_pages_commited : 795365 // total pages used by the Guest userspace
+ total_pages_commited : 977790 // total pages used by the Guest
user+kernel
+ max_dynamic_page_count: 268435456 // maximum pages the Guest can have added
+ // via hot_add
+
+Hyper-V balloon driver changes TOTAL RAM size reported by the Guest,
+thus the "InflatedTotal" counter will be non-zero in memory statistic
+reported during OOM or upon Alt+SysRQ+m.
+
+Hyper-V balloon
+---------------
+
+Balloon guest statistics output example::
+ # cat /sys/kernel/debug/vmmemctl
+ balloon capabilities: 0x1e
+ used capabilities: 0x6
+ is resetting: n
+ target: 0 pages
+ current: 0 pages
+ rateSleepAlloc: 2048 pages/sec
+
+ timer: 118
+ doorbell: 0
+ start: 1 ( 0 failed)
+ guestType: 1 ( 0 failed)
+ 2m-lock: 0 ( 0 failed)
+ lock: 0 ( 0 failed)
+ 2m-unlock: 0 ( 0 failed)
+ unlock: 0 ( 0 failed)
+ target: 118 ( 0 failed)
+ prim2mAlloc: 0 ( 0 failed)
+ primNoSleepAlloc: 0 ( 0 failed)
+ primCanSleepAlloc: 0 ( 0 failed)
+ prim2mFree: 0
+ primFree: 0
+ err2mAlloc: 0
+ errAlloc: 0
+ err2mFree: 0
+ errFree: 0
+ doorbellSet: 0
+ doorbellUnset: 1
+
+VMware balloon driver makes ballooned pages accounted as "used" in the
+Guest OS thus the "InflatedFree" counter will be non-zero in memory
+statistic reported during OOM or upon Alt+SysRQ+m.
+
+https://jira.sw.ru/browse/PSBM-140408
https://jira.sw.ru/browse/PSBM-140409
https://jira.sw.ru/browse/PSBM-140407
+https://jira.sw.ru/browse/PSBM-142436
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