[libvirt PATCH] NEWS: mention cgroups on hosts with systemd bug fix

Pavel Hrdina posted 1 patch 3 years, 2 months ago
Test syntax-check failed
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/libvirt tags/patchew/a2bc1967c45dd76321c494c596d7e905a62bdcc7.1614006556.git.phrdina@redhat.com
NEWS.rst | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
[libvirt PATCH] NEWS: mention cgroups on hosts with systemd bug fix
Posted by Pavel Hrdina 3 years, 2 months ago
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
---
 NEWS.rst | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/NEWS.rst b/NEWS.rst
index bee49923a5..eac86d8a4e 100644
--- a/NEWS.rst
+++ b/NEWS.rst
@@ -71,6 +71,23 @@ v7.1.0 (unreleased)
    of relying on ``VIR_DOMAIN_SNAPSHOT_CREATE_QUIESCE`` if they need finer
    grained control.
 
+  * cgroups: Fix how we setup and configure cgroups on hosts with systemd
+
+    When libvirt is running on host with systemd we register every VM with
+    machined which creates the VM root cgroup for us as well. Before this fix
+    we were directly modifying files in the VM root cgroup which was incorrect
+    because all the files are managed by systemd. The implication was that any
+    change done by libvirt to cgroup attributes supported by systemd could be
+    removed which happens for example by running ``systemctl daemon-reload``.
+
+    To fix the issue libvirt now uses DBus calls for some of the cgroup
+    attributes that distributes the resources proportionally to the cgroup
+    siblings and for the rest we have new sub-cgroup that libvirt can managed
+    directly.
+
+    For more details why this is necessary see
+    `systemd cgroug <https://systemd.io/CGROUP_DELEGATION/>`_ documentation.
+
 
 v7.0.0 (2021-01-15)
 ===================
-- 
2.29.2

Re: [libvirt PATCH] NEWS: mention cgroups on hosts with systemd bug fix
Posted by Andrea Bolognani 3 years, 2 months ago
On Mon, 2021-02-22 at 16:09 +0100, Pavel Hrdina wrote:
> +    To fix the issue libvirt now uses DBus calls for some of the cgroup
> +    attributes that distributes the resources proportionally to the cgroup

I think this should be s/distributes/distribute/

> +    siblings and for the rest we have new sub-cgroup that libvirt can managed

"a new sub-cgroup that libvirt can manage"

> +    directly.
> +
> +    For more details why this is necessary see
> +    `systemd cgroug <https://systemd.io/CGROUP_DELEGATION/>`_ documentation.

s/cgroug/cgroup/

With these nits fixed,

  Reviewed-by: Andrea Bolognani <abologna@redhat.com>

-- 
Andrea Bolognani / Red Hat / Virtualization