Prior to rewrite of cgroup code we only had one backend to try.
After the rewrite the virCgroupBackendGetAll() returns both
backends (for v1 and v2). However, not both have to really be
present on the system which results in killRecursive callback
failing which in turn might mean we won't try the other backend.
At the same time, this function reports no error as it should.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
Missing semicolon at the end of macros can confuse some analyzers
(like cppcheck <filename>), and we have a mix of semicolon and
non-semicolon usage through the code. Let's standardize on using
a semicolon for VIR_ENUM_IMPL calls.
Move the verify() statement to the end of the macro and drop
the semicolon, so the compiler will require callers to add a
semicolon.
While we are touching these call sites, standardize on putting
the closing parenth on its own line, as discussed here:
https://www.redhat.com/archives/libvir-list/2019-January/msg00750.html
Reviewed-by: John Ferlan <jferlan@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
Require that all headers are guarded by a symbol named
LIBVIRT_$FILENAME
where $FILENAME is the uppercased filename, with all characters
outside a-z changed into '_'.
Note we do not use a leading __ because that is technically a
namespace reserved for the toolchain.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
The rewrite to support cgroup v2 missed this function. In cgroup v2
we have different files to track tasks.
We would fail to remove cgroup on non-systemd OSes if there is any
extra process assigned to guest cgroup because we would not kill any
process form the guest cgroup.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
In many files there are header comments that contain an Author:
statement, supposedly reflecting who originally wrote the code.
In a large collaborative project like libvirt, any non-trivial
file will have been modified by a large number of different
contributors. IOW, the Author: comments are quickly out of date,
omitting people who have made significant contribitions.
In some places Author: lines have been added despite the person
merely being responsible for creating the file by moving existing
code out of another file. IOW, the Author: lines give an incorrect
record of authorship.
With this all in mind, the comments are useless as a means to identify
who to talk to about code in a particular file. Contributors will always
be better off using 'git log' and 'git blame' if they need to find the
author of a particular bit of code.
This commit thus deletes all Author: comments from the source and adds
a rule to prevent them reappearing.
The Copyright headers are similarly misleading and inaccurate, however,
we cannot delete these as they have legal meaning, despite being largely
inaccurate. In addition only the copyright holder is permitted to change
their respective copyright statement.
Reviewed-by: Erik Skultety <eskultet@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This enables to use both cgroup v1 and v2 at the same time together
with libvirt. It is supported by kernel and there is valid use-case,
not all controllers are implemented in cgroup v2 so there might be
configurations where administrator would enable these missing
controllers in cgroup v1.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
When creating cgroup hierarchy we need to enable controllers in the
parent cgroup in order to be usable. That means writing "+{controller}"
into cgroup.subtree_control file. We can enable only controllers that
are enabled for parent cgroup, that means we need to do that for the
whole cgroup tree.
Cgroups for threads needs to be handled differently in cgroup v2. There
are two types of controllers:
- domain controllers: these cannot be enabled for threads
- threaded controllers: these can be enabled for threads
In addition there are multiple types of cgroups:
- domain: normal cgroup
- domain threaded: a domain cgroup that serves as root for threaded
cgroups
- domain invalid: invalid cgroup, can be changed into threaded, this
is the default state if you create subgroup inside
domain threaded group or threaded group
- threaded: threaded cgroup which can have domain threaded or
threaded as parent group
In order to create threaded cgroup it's sufficient to write "threaded"
into cgroup.type file, it will automatically make parent cgroup
"domain threaded" if it was only "domain". In case the parent cgroup
is already "domain threaded" or "threaded" it will modify only the type
of current cgroup. After that we can enable threaded controllers.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Place cgroup v2 backend type before cgroup v1 to make it obvious
that cgroup v2 is preferred implementation.
Following patches will introduce support for hybrid configuration
which will allow us to use both at the same time, but we should
prefer cgroup v2 regardless.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
This reverts commit 1602aa28f8.
There is no need to call virCgroupRemove() nor virCgroupFree() if
virCgroupEnableMissingControllers() fails because it will not modify
'group' at all.
The cleanup of directories is done in virCgroupMakeGroup().
Reviewed-by: John Ferlan <jferlan@redhat.com>
Reviewed-by: Fabiano Fidêncio <fidencio@redhat.com>
Reviewed-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
All the system headers are used only if we are compiling on linux
and they all are present otherwise we would have seen build errors
because in our tests/vircgrouptest.c we use only __linux__ to check
whether to skip the cgroup tests or not.
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
tests/vircgrouptest.c uses #ifdef __linux__ for a long time and no
failure was reported so far so it's safe to assume that __linux__ is
good enough to guard cgroup code.
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
With the introduction of cgroup v2 there are new names used with
cgroups based on which version is used:
- legacy: cgroup v1
- unified: cgroup v2
- hybrid: cgroup v1 and cgroup v2
Let's use 'legacy' instead of 'cgroupv1' or 'controllers' in our code.
Reviewed-by: Fabiano Fidêncio <fidencio@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
They all need virCgroupV1GetMemoryUnlimitedKB() so it's easier to
move them in one commit.
Reviewed-by: Fabiano Fidêncio <fidencio@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
