Because of a systemd delegation policy [1] we should not write to any
cgroups files owned by systemd which in case of cgroups v2 includes
'cgroups.subtree_control'.
systemd will enable controllers automatically for us to have them
available for VM cgroups.
[1] <https://github.com/systemd/systemd/blob/master/docs/CGROUP_DELEGATION.md>
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
This reverts commit 7bca1c9bdc.
As it turns out it's not a good idea on systemd hosts. The root
cgroup can have all controllers enabled but they don't have to be
enabled for sub-cgroups.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
When detecting available controllers on host we can be limited by list
of controllers from qemu.conf file.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Currently CPU controller cannot be enabled if there is any real-time
task running and is assigned to non-root cgroup which is the case on
several distributions with graphical environment.
Instead of erroring out treat it as the controller is not available.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
In order to skip controllers that we are not able to activate we need
to return different return value so the caller can decide what to do.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
It might happen that we are not able to enable CPU controller so we
can enable it for thread sub-cgroups only if it's available in parent
cgroup.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
The assumption that CPU controller would be always enabled is wrong, we
should use any available controller to create a new sub-cgroup.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
This affects only cgroups v2 where enabled controllers are not based on
available mount points but on the list provided in cgroup.controllers
file. However, moving it will fill in placement as well, so it needs
to be freed together with mount point if we don't need that controller.
Before this patch we were assuming that all controllers available in
root cgroup where available in all other sub-cgroups which was wrong.
In order to fix it we need to move the cgroup controllers detection
after cgroup placement was prepared in order to build correct path for
cgroup.controllers file.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
In cgroups v2 we don't have to detect available controllers every single
time if we are creating a new cgroup based on parent cgroup.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
In kernel 4.12 there was introduced new BFQ scheduler and in kernel
5.0 the old CFQ scheduler was removed. This has an implication on
the cgroups file names.
If the CFQ controller is enabled we use one file:
io.weight
The new BFQ controller expose one file with different name:
io.bfq.weight
Except for different name they have different syntax.
io.weight:
default $val
major:minor $val
io.bfq.weight:
$val
The difference is that BFQ doesn't support per-device weight.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
If we need to get a path of specific file and we need to check its
existence before we use it then we can reuse that path to get value
for specific device. This way we will not build the path again in
virCgroupGetValueForBlkDev.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Standardize on putting the _LAST enum value on the second line
of VIR_ENUM_IMPL invocations. Later patches that add string labels
to VIR_ENUM_IMPL will push most of these to the second line anyways,
so this saves some noise.
Signed-off-by: Cole Robinson <crobinso@redhat.com>
This reverts commit a5e1602090.
Getting rid of unistd.h from our headers will require more work than
just fixing the broken mingw build. Revert it until I have a more
complete proposal.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
util/virutil.h bogously included unistd.h. Drop it and replace it by
including it directly where needed.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
'viralloc.h' does not provide any type or macro which would be necessary
in headers. Prevent leakage of the inclusion.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@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 $FILENAME is the uppercased filename, with all characters
outside a-z changed into '_'.
Note we do not use a leading __ because that is technically a
namespace reserved for the toolchain.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
When libvirt is reconnecting to running domain that uses cgroup v2
the QEMU process reports cgroup for the emulator directory because the
main thread is in that cgroup. We need to remove the "/emulator" part
in order to match with the root cgroup directory name for that domain.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
The rewrite to support cgroup v2 missed this function. In cgroup v2
we have different files to track tasks.
We would fail to remove cgroup on non-systemd OSes if there is any
extra process assigned to guest cgroup because we would not kill any
process form the guest cgroup.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Commit 901d2b9c introduced virCgroupGetMemoryStat and replaced
the LXC virLXCCgroupGetMemStat logic in commit e634c7cd0. However,
in doing so the replacement wasn't exact as the LXC logic used
getline() to process the cgroup controller data, while the new
virCgroupGetMemoryStat used "memory.stat" manual buffer read/
processing which neglected to forward through @line in order
to read each line in the output.
To fix that, we should be sure to carry forward the @line value
for each line read updating it beyond that current @newLine value
once we've calculated the values that we want.
Signed-off-by: Peter Chubb <peter.chubb@data61.csiro.au>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
In order to set CPU cfs period using cgroup v2 'cpu.max' interface
we need to load the current value of CPU cfs quota first because
format of 'cpu.max' interface is '$quota $period' and in order to
change 'period' we need to write 'quota' as well. Writing only one
number changes only 'quota'.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
In cgroups v2 we need to handle threads and processes differently.
If you need to move a process you need to write its pid into
cgrou.procs file and it will move the process with all its threads
as well. The whole process will be moved if you use tid of any thread.
In order to move only threads at first we need to create threaded group
and after that we can write the relevant thread tids into cgroup.threads
file. Threads can be moved only into cgroups that are children of
cgroup of its process.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
