[pve-devel] [PATCH pve-container 0/3] use generic CGroup module

[pve-devel] [PATCH pve-container 0/3] use generic CGroup module

[Alexandre Derumier]

following pve-common patch series

Alexandre Derumier (3):
  Cgroups: use base PVE::CGroup and keep specific lxc code
  use PVE::CGroup
  cgroup: get_subdir: return cgroupv2 path for undef controller

 src/PVE/LXC.pm            |   7 +-
 src/PVE/LXC/CGroup.pm     | 533 +-------------------------------------
 src/lxc-pve-prestart-hook |   2 +-
 3 files changed, 9 insertions(+), 533 deletions(-)

-- 
2.20.1

[pve-devel] [PATCH pve-container 1/3] Cgroups: use base PVE::CGroup and keep specific lxc code

[Alexandre Derumier]

---
 src/PVE/LXC/CGroup.pm | 532 +-----------------------------------------
 1 file changed, 3 insertions(+), 529 deletions(-)

diff --git a/src/PVE/LXC/CGroup.pm b/src/PVE/LXC/CGroup.pm
index 6710843..19562c2 100644
--- a/src/PVE/LXC/CGroup.pm
+++ b/src/PVE/LXC/CGroup.pm
@@ -12,155 +12,10 @@ package PVE::LXC::CGroup;
 use strict;
 use warnings;
 
-use IO::File;
-use IO::Select;
-use POSIX qw();
-
-use PVE::ProcFSTools;
-use PVE::Tools qw(
-    file_get_contents
-    file_read_firstline
-);
-
 use PVE::LXC::Command;
+use PVE::CGroup;
+use base('PVE::CGroup');
 
-# We don't want to do a command socket round trip for every cgroup read/write,
-# so any cgroup function needs to have the container's path cached, so this
-# package has to be instantiated.
-#
-# LXC keeps separate paths by controller (although they're normally all the
-# same, in our # case anyway), so we cache them by controller as well.
-sub new {
-    my ($class, $vmid) = @_;
-
-    my $self = { vmid => $vmid };
-
-    return bless $self, $class;
-}
-
-# Get the v1 controller list.
-#
-# Returns a set (hash mapping names to `1`) of cgroupv1 controllers, and an
-# optional boolean whether a unified (cgroupv2) hierarchy exists.
-#
-# Deprecated: Use `get_cgroup_controllers()` instead.
-sub get_v1_controllers {
-    my $v1 = {};
-    my $v2 = 0;
-    my $data = PVE::Tools::file_get_contents('/proc/self/cgroup');
-    while ($data =~ /^\d+:([^:\n]*):.*$/gm) {
-	my $type = $1;
-	if (length($type)) {
-	    $v1->{$_} = 1 foreach split(/,/, $type);
-	} else {
-	    $v2 = 1;
-	}
-    }
-    return wantarray ? ($v1, $v2) : $v1;
-}
-
-# Get the set v2 controller list from the `cgroup.controllers` file.
-my sub get_v2_controllers {
-    my $v2 = eval { file_get_contents('/sys/fs/cgroup/cgroup.controllers') }
-	|| eval { file_get_contents('/sys/fs/cgroup/unified/cgroup.controllers') };
-    return undef if !defined $v2;
-
-    # It's a simple space separated list:
-    return { map { $_ => 1 } split(/\s+/, $v2) };
-}
-
-my $CGROUP_CONTROLLERS = undef;
-# Get a list of controllers enabled in each cgroup subsystem.
-#
-# This is a more complete version of `PVE::LXC::get_cgroup_subsystems`.
-#
-# Returns 2 sets (hashes mapping controller names to `1`), one for each cgroup
-# version.
-sub get_cgroup_controllers() {
-    if (!defined($CGROUP_CONTROLLERS)) {
-	my ($v1, undef) = get_v1_controllers();
-	my $v2 = get_v2_controllers();
-
-	$CGROUP_CONTROLLERS = [$v1, $v2];
-    }
-
-    return $CGROUP_CONTROLLERS->@*;
-}
-
-my $CGROUP_MODE = undef;
-# Figure out which cgroup mode we're operating under:
-#
-# Returns 1 if cgroupv1 controllers exist (hybrid or legacy mode), and 2 in a
-# cgroupv2-only environment.
-#
-# NOTE: To fully support a hybrid layout it is better to use functions like
-# `cpuset_controller_path`.
-#
-# This is a function, not a method!
-sub cgroup_mode() {
-    if (!defined($CGROUP_MODE)) {
-	my ($v1, $v2) = get_cgroup_controllers();
-	if (keys %$v1) {
-	    # hybrid or legacy mode
-	    $CGROUP_MODE = 1;
-	} elsif ($v2) {
-	    $CGROUP_MODE = 2;
-	}
-    }
-
-    die "unknown cgroup mode\n" if !defined($CGROUP_MODE);
-    return $CGROUP_MODE;
-}
-
-my $CGROUPV2_PATH = undef;
-sub cgroupv2_base_path() {
-    if (!defined($CGROUPV2_PATH)) {
-	if (cgroup_mode() == 2) {
-	    $CGROUPV2_PATH = '/sys/fs/cgroup';
-	} else {
-	    $CGROUPV2_PATH = '/sys/fs/cgroup/unified';
-	}
-    }
-    return $CGROUPV2_PATH;
-}
-
-# Find a cgroup controller and return its path and version.
-#
-# LXC initializes the unified hierarchy first, so if a controller is
-# available via both we favor cgroupv2 here as well.
-#
-# Returns nothing if the controller is not available.
-sub find_cgroup_controller($) {
-    my ($controller) = @_;
-
-    my ($v1, $v2) = get_cgroup_controllers();
-
-    if (!defined($controller) || $v2->{$controller}) {
-	my $path = cgroupv2_base_path();
-	return wantarray ? ($path, 2) : $path;
-    }
-
-    if (defined($controller) && $v1->{$controller}) {
-	my $path = "/sys/fs/cgroup/$controller";
-	return wantarray ? ($path, 1) : $path;
-    }
-
-    return;
-}
-
-my $CG_PATH_CPUSET = undef;
-my $CG_VER_CPUSET = undef;
-# Find the cpuset cgroup controller.
-#
-# This is a function, not a method!
-sub cpuset_controller_path() {
-    if (!defined($CG_PATH_CPUSET)) {
-	($CG_PATH_CPUSET, $CG_VER_CPUSET) = find_cgroup_controller('cpuset')
-	    or die "failed to find cpuset controller\n";
-    }
-
-    return wantarray ? ($CG_PATH_CPUSET, $CG_VER_CPUSET) : $CG_PATH_CPUSET;
-}
 
 # Get a subdirectory (without the cgroup mount point) for a controller.
 #
@@ -170,7 +25,7 @@ sub cpuset_controller_path() {
 # (`cgroup.controllers` file) as list of controllers for the unified hierarchy,
 # so this returns a result when a `controller` is provided even when using
 # a pure cgroupv2 setup.
-my sub get_subdir {
+sub get_subdir {
     my ($self, $controller, $limiting) = @_;
 
     my $entry_name = $controller || 'unified';
@@ -198,385 +53,4 @@ my sub get_subdir {
     return $path;
 }
 
-# Get path and version for a controller.
-#
-# `$controller` may be `undef`, see get_subdir above for details.
-#
-# Returns either just the path, or the path and cgroup version as a tuple.
-sub get_path {
-    my ($self, $controller, $limiting) = @_;
-
-    # Find the controller before querying the lxc monitor via a socket:
-    my ($cgpath, $ver) = find_cgroup_controller($controller)
-	or return undef;
-
-    my $path = get_subdir($self, $controller, $limiting)
-	or return undef;
-
-    $path = "$cgpath/$path";
-    return wantarray ? ($path, $ver) : $path;
-}
-
-# Convenience method to get the path info if the first existing controller.
-#
-# Returns the same as `get_path`.
-sub get_any_path {
-    my ($self, $limiting, @controllers) = @_;
-
-    my ($path, $ver);
-    for my $c (@controllers) {
-	($path, $ver) = $self->get_path($c, $limiting);
-	last if defined $path;
-    }
-    return wantarray ? ($path, $ver) : $path;
-}
-
-# Parse a 'Nested keyed' file:
-#
-# See kernel documentation `admin-guide/cgroup-v2.rst` 4.1.
-my sub parse_nested_keyed_file($) {
-    my ($data) = @_;
-    my $res = {};
-    foreach my $line (split(/\n/, $data)) {
-	my ($key, @values) = split(/\s+/, $line);
-
-	my $d = ($res->{$key} = {});
-
-	foreach my $value (@values) {
-	    if (my ($key, $value) = ($value =~ /^([^=]+)=(.*)$/)) {
-		$d->{$key} = $value;
-	    } else {
-		warn "bad key=value pair in nested keyed file\n";
-	    }
-	}
-    }
-    return $res;
-}
-
-# Parse a 'Flat keyed' file:
-#
-# See kernel documentation `admin-guide/cgroup-v2.rst` 4.1.
-my sub parse_flat_keyed_file($) {
-    my ($data) = @_;
-    my $res = {};
-    foreach my $line (split(/\n/, $data)) {
-	if (my ($key, $value) = ($line =~ /^(\S+)\s+(.*)$/)) {
-	    $res->{$key} = $value;
-	} else {
-	    warn "bad 'key value' pair in flat keyed file\n";
-	}
-    }
-    return $res;
-}
-
-# Parse out 'diskread' and 'diskwrite' values from I/O stats for this container.
-sub get_io_stats {
-    my ($self) = @_;
-
-    my $res = {
-	diskread => 0,
-	diskwrite => 0,
-    };
-
-    # With cgroupv1 we have a 'blkio' controller, with cgroupv2 it's just 'io':
-    my ($path, $ver) = $self->get_any_path(1, 'io', 'blkio');
-    if (!defined($path)) {
-	# container not running
-	return undef;
-    } elsif ($ver == 2) {
-	# cgroupv2 environment, io controller enabled
-	my $io_stat = file_get_contents("$path/io.stat");
-
-	my $data = parse_nested_keyed_file($io_stat);
-	foreach my $dev (keys %$data) {
-	    my $dev = $data->{$dev};
-	    if (my $b = $dev->{rbytes}) {
-		$res->{diskread} += $b;
-	    }
-	    if (my $b = $dev->{wbytes}) {
-		$res->{diskread} += $b;
-	    }
-	}
-
-	return $res;
-    } elsif ($ver == 1) {
-	# cgroupv1 environment:
-	my $io = file_get_contents("$path/blkio.throttle.io_service_bytes_recursive");
-	foreach my $line (split(/\n/, $io)) {
-	    if (my ($type, $bytes) = ($line =~ /^\d+:\d+\s+(Read|Write)\s+(\d+)$/)) {
-		$res->{diskread} += $bytes if $type eq 'Read';
-		$res->{diskwrite} += $bytes if $type eq 'Write';
-	    }
-	}
-
-	return $res;
-    } else {
-	die "bad cgroup version: $ver\n";
-    }
-
-    # container not running
-    return undef;
-}
-
-# Read utime and stime for this container from the cpuacct cgroup.
-# Values are in milliseconds!
-sub get_cpu_stat {
-    my ($self) = @_;
-
-    my $res = {
-	utime => 0,
-	stime => 0,
-    };
-
-    my ($path, $ver) = $self->get_any_path(1, 'cpuacct', 'cpu');
-    if (!defined($path)) {
-	# container not running
-	return undef;
-    } elsif ($ver == 2) {
-	my $data = eval { file_get_contents("$path/cpu.stat") };
-
-	# or no io controller available:
-	return undef if !defined($data);
-
-	$data = parse_flat_keyed_file($data);
-	$res->{utime} = int($data->{user_usec} / 1000);
-	$res->{stime} = int($data->{system_usec} / 1000);
-    } elsif ($ver == 1) {
-	# cgroupv1 environment:
-	my $clock_ticks = POSIX::sysconf(&POSIX::_SC_CLK_TCK);
-	my $clk_to_usec = 1000 / $clock_ticks;
-
-	my $data = parse_flat_keyed_file(file_get_contents("$path/cpuacct.stat"));
-	$res->{utime} = int($data->{user} * $clk_to_usec);
-	$res->{stime} = int($data->{system} * $clk_to_usec);
-    } else {
-	die "bad cgroup version: $ver\n";
-    }
-
-    return $res;
-}
-
-# Parse some memory data from `memory.stat`
-sub get_memory_stat {
-    my ($self) = @_;
-
-    my $res = {
-	mem => 0,
-	swap => 0,
-    };
-
-    my ($path, $ver) = $self->get_path('memory', 1);
-    if (!defined($path)) {
-	# container most likely isn't running
-	return undef;
-    } elsif ($ver == 2) {
-	my $mem = file_get_contents("$path/memory.current");
-	my $swap = file_get_contents("$path/memory.swap.current");
-
-	chomp ($mem, $swap);
-
-	# FIXME: For the cgv1 equivalent of `total_cache` we may need to sum up
-	# the values in `memory.stat`...
-
-	$res->{mem} = $mem;
-	$res->{swap} = $swap;
-    } elsif ($ver == 1) {
-	# cgroupv1 environment:
-	my $stat = parse_flat_keyed_file(file_get_contents("$path/memory.stat"));
-	my $mem = file_get_contents("$path/memory.usage_in_bytes");
-	my $memsw = file_get_contents("$path/memory.memsw.usage_in_bytes");
-	chomp ($mem, $memsw);
-
-	$res->{mem} = $mem - $stat->{total_cache};
-	$res->{swap} = $memsw - $mem;
-    } else {
-	die "bad cgroup version: $ver\n";
-    }
-
-    return $res;
-}
-
-# Change the memory limit for this container.
-#
-# Dies on error (including a not-running or currently-shutting-down guest).
-sub change_memory_limit {
-    my ($self, $mem_bytes, $swap_bytes) = @_;
-
-    my ($path, $ver) = $self->get_path('memory', 1);
-    if (!defined($path)) {
-	die "trying to change memory cgroup values: container not running\n";
-    } elsif ($ver == 2) {
-	PVE::ProcFSTools::write_proc_entry("$path/memory.swap.max", $swap_bytes)
-	    if defined($swap_bytes);
-	PVE::ProcFSTools::write_proc_entry("$path/memory.max", $mem_bytes)
-	    if defined($mem_bytes);
-    } elsif ($ver == 1) {
-	# With cgroupv1 we cannot control memory and swap limits separately.
-	# This also means that since the two values aren't independent, we need to handle
-	# growing and shrinking separately.
-	my $path_mem = "$path/memory.limit_in_bytes";
-	my $path_memsw = "$path/memory.memsw.limit_in_bytes";
-
-	my $old_mem_bytes = file_get_contents($path_mem);
-	my $old_memsw_bytes = file_get_contents($path_memsw);
-	chomp($old_mem_bytes, $old_memsw_bytes);
-
-	$mem_bytes //= $old_mem_bytes;
-	$swap_bytes //= $old_memsw_bytes - $old_mem_bytes;
-	my $memsw_bytes = $mem_bytes + $swap_bytes;
-
-	if ($memsw_bytes > $old_memsw_bytes) {
-	    # Growing the limit means growing the combined limit first, then pulling the
-	    # memory limitup.
-	    PVE::ProcFSTools::write_proc_entry($path_memsw, $memsw_bytes);
-	    PVE::ProcFSTools::write_proc_entry($path_mem, $mem_bytes);
-	} else {
-	    # Shrinking means we first need to shrink the mem-only memsw cannot be
-	    # shrunk below it.
-	    PVE::ProcFSTools::write_proc_entry($path_mem, $mem_bytes);
-	    PVE::ProcFSTools::write_proc_entry($path_memsw, $memsw_bytes);
-	}
-    } else {
-	die "bad cgroup version: $ver\n";
-    }
-
-    # return a truth value
-    return 1;
-}
-
-# Change the cpu quota for a container.
-#
-# Dies on error (including a not-running or currently-shutting-down guest).
-sub change_cpu_quota {
-    my ($self, $quota, $period) = @_;
-
-    die "quota without period not allowed\n" if !defined($period) && defined($quota);
-
-    my ($path, $ver) = $self->get_path('cpu', 1);
-    if (!defined($path)) {
-	die "trying to change cpu quota cgroup values: container not running\n";
-    } elsif ($ver == 2) {
-	# cgroupv2 environment, an undefined (unlimited) quota is defined as "max"
-	# in this interface:
-	$quota //= 'max'; # unlimited
-	if (defined($quota)) {
-	    PVE::ProcFSTools::write_proc_entry("$path/cpu.max", "$quota $period");
-	} else {
-	    # we're allowed to only write the quota:
-	    PVE::ProcFSTools::write_proc_entry("$path/cpu.max", 'max');
-	}
-    } elsif ($ver == 1) {
-	$quota //= -1; # unlimited
-	$period //= -1;
-	PVE::ProcFSTools::write_proc_entry("$path/cpu.cfs_period_us", $period);
-	PVE::ProcFSTools::write_proc_entry("$path/cpu.cfs_quota_us", $quota);
-    } else {
-	die "bad cgroup version: $ver\n";
-    }
-
-    # return a truth value
-    return 1;
-}
-
-# Change the cpu "shares" for a container.
-#
-# In cgroupv1 we used a value in `[0..500000]` with a default of 1024.
-#
-# In cgroupv2 we do not have "shares", we have "weights" in the range
-# of `[1..10000]` with a default of 100.
-#
-# Since the default values don't match when scaling linearly, we use the
-# values we get as-is and simply error for values >10000 in cgroupv2.
-#
-# It is left to the user to figure this out for now.
-#
-# Dies on error (including a not-running or currently-shutting-down guest).
-sub change_cpu_shares {
-    my ($self, $shares, $cgroupv1_default) = @_;
-
-    my ($path, $ver) = $self->get_path('cpu', 1);
-    if (!defined($path)) {
-	die "trying to change cpu shares/weight cgroup values: container not running\n";
-    } elsif ($ver == 2) {
-	# the cgroupv2 documentation defines the default to 100
-	$shares //= 100;
-	die "cpu weight (shares) must be in range [1, 10000]\n" if $shares < 1 || $shares > 10000;
-	PVE::ProcFSTools::write_proc_entry("$path/cpu.weight", $shares);
-    } elsif ($ver == 1) {
-	$shares //= 100;
-	PVE::ProcFSTools::write_proc_entry("$path/cpu.shares", $shares // $cgroupv1_default);
-    } else {
-	die "bad cgroup version: $ver\n";
-    }
-
-    # return a truth value
-    return 1;
-}
-
-my sub v1_freeze_thaw {
-    my ($self, $controller_path, $freeze) = @_;
-    my $path = get_subdir($self, 'freezer', 1)
-	or die "trying to freeze container: container not running\n";
-    $path = "$controller_path/$path/freezer.state";
-
-    my $data = $freeze ? 'FROZEN' : 'THAWED';
-    PVE::ProcFSTools::write_proc_entry($path, $data);
-
-    # Here we just poll the freezer.state once per second.
-    while (1) {
-	my $state = file_get_contents($path);
-	chomp $state;
-	last if $state eq $data;
-    }
-}
-
-my sub v2_freeze_thaw {
-    my ($self, $controller_path, $freeze) = @_;
-    my $path = get_subdir($self, undef, 1)
-	or die "trying to freeze container: container not running\n";
-    $path = "$controller_path/$path";
-
-    my $desired_state = $freeze ? 1 : 0;
-
-    # cgroupv2 supports poll events on cgroup.events which contains the frozen
-    # state.
-    my $fh = IO::File->new("$path/cgroup.events", 'r')
-	or die "failed to open $path/cgroup.events file: $!\n";
-    my $select = IO::Select->new();
-    $select->add($fh);
-
-    PVE::ProcFSTools::write_proc_entry("$path/cgroup.freeze", $desired_state);
-    while (1) {
-	my $data = do {
-	    local $/ = undef;
-	    <$fh>
-	};
-	$data = parse_flat_keyed_file($data);
-	last if $data->{frozen} == $desired_state;
-	my @handles = $select->has_exception();
-	next if !@handles;
-	seek($fh, 0, 0)
-	    or die "failed to rewind cgroup.events file: $!\n";
-    }
-}
-
-# Freeze or unfreeze a container.
-#
-# This will freeze the container at its outer (limiting) cgroup path. We use
-# this instead of `lxc-freeze` as `lxc-freeze` from lxc4 will not be able to
-# fetch the cgroup path from contaienrs still running on lxc3.
-sub freeze_thaw {
-    my ($self, $freeze) = @_;
-
-    my $controller_path = find_cgroup_controller('freezer');
-    if (defined($controller_path)) {
-	return v1_freeze_thaw($self, $controller_path, $freeze);
-    } else {
-	# cgroupv2 always has a freezer, there can be both cgv1 and cgv2
-	# freezers, but we'll prefer v1 when it's available as that's what lxc
-	# does as well...
-	return v2_freeze_thaw($self, cgroupv2_base_path(), $freeze);
-    }
-}
-
 1;
-- 
2.20.1

[pve-devel] [PATCH pve-container 2/3] use PVE::CGroup

[Alexandre Derumier]

---
 src/PVE/LXC.pm            | 7 ++++---
 src/lxc-pve-prestart-hook | 2 +-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/PVE/LXC.pm b/src/PVE/LXC.pm
index 9c150d9..5cfcf28 100644
--- a/src/PVE/LXC.pm
+++ b/src/PVE/LXC.pm
@@ -33,6 +33,7 @@ use PVE::GuestHelpers qw(safe_string_ne safe_num_ne safe_boolean_ne);
 use PVE::LXC::Tools;
 use PVE::LXC::CGroup;
 use PVE::LXC::Monitor;
+use PVE::CGroup;
 
 use Time::HiRes qw (gettimeofday);
 my $have_sdn;
@@ -402,9 +403,9 @@ sub parse_ipv4_cidr {
     die "unable to parse ipv4 address/mask\n";
 }
 
-# Deprecated. Use `PVE::LXC::CGroup::get_cgroup_controllers()` instead.
+# Deprecated. Use `PVE::CGroup::get_cgroup_controllers()` instead.
 sub get_cgroup_subsystems {
-    PVE::LXC::CGroup::get_v1_controllers();
+    PVE::CGroup::get_v1_controllers();
 }
 
 # With seccomp trap to userspace we now have the ability to optionally forward
@@ -708,7 +709,7 @@ sub update_lxc_config {
     }
 
     my $cpuset;
-    my ($cpuset_cgroup, $cpuset_version) = eval { PVE::LXC::CGroup::cpuset_controller_path() };
+    my ($cpuset_cgroup, $cpuset_version) = eval { PVE::CGroup::cpuset_controller_path() };
     if (defined($cpuset_cgroup)) {
 	$cpuset = eval { PVE::CpuSet->new_from_path("$cpuset_cgroup/lxc", 1) }
 	    || PVE::CpuSet->new_from_path($cpuset_cgroup, 1);
diff --git a/src/lxc-pve-prestart-hook b/src/lxc-pve-prestart-hook
index 8823cad..40d58c4 100755
--- a/src/lxc-pve-prestart-hook
+++ b/src/lxc-pve-prestart-hook
@@ -144,7 +144,7 @@ PVE::LXC::Tools::lxc_hook('pre-start', 'lxc', sub {
 sub cleanup_cgroups($) {
     my ($vmid) = @_;
 
-    if (PVE::LXC::CGroup::cgroup_mode() == 2) {
+    if (PVE::CGroup::cgroup_mode() == 2) {
 	rmdir_recursive("/sys/fs/cgroup/lxc/$vmid");
 	rmdir_recursive("/sys/fs/cgroup/lxc.monitor/$vmid");
     } else {
-- 
2.20.1

[pve-devel] [PATCH pve-container 3/3] cgroup: get_subdir: return cgroupv2 path for undef controller

[Alexandre Derumier]

---
 src/PVE/LXC/CGroup.pm | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/PVE/LXC/CGroup.pm b/src/PVE/LXC/CGroup.pm
index 19562c2..74d84c4 100644
--- a/src/PVE/LXC/CGroup.pm
+++ b/src/PVE/LXC/CGroup.pm
@@ -35,6 +35,7 @@ sub get_subdir {
     my $path = $entry->{$kind};
 
     return $path if defined $path;
+    return "/lxc/$self->{vmid}" if !$controller;
 
     $path = PVE::LXC::Command::get_cgroup_path(
 	$self->{vmid},
-- 
2.20.1

Re: [pve-devel] [PATCH pve-container 3/3] cgroup: get_subdir: return cgroupv2 path for undef controller

[Wolfgang Bumiller]

On Fri, Oct 30, 2020 at 10:42:28AM +0100, Alexandre Derumier wrote:
> ---
>  src/PVE/LXC/CGroup.pm | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/src/PVE/LXC/CGroup.pm b/src/PVE/LXC/CGroup.pm
> index 19562c2..74d84c4 100644
> --- a/src/PVE/LXC/CGroup.pm
> +++ b/src/PVE/LXC/CGroup.pm
> @@ -35,6 +35,7 @@ sub get_subdir {
>      my $path = $entry->{$kind};
>  
>      return $path if defined $path;
> +    return "/lxc/$self->{vmid}" if !$controller;

Why exactly are you doing this? `get_cgroup_path` should work with an
undef $controller value. Also, this ignores the $limiting parameter (and
the main point for using the command socket was to not hardcode paths at
all)
So what kind of problem did you run into there?

>  
>      $path = PVE::LXC::Command::get_cgroup_path(
>  	$self->{vmid},
> -- 
> 2.20.1

[pve-devel] partially applied series: [PATCH pve-container 0/3] use generic CGroup module

[Wolfgang Bumiller]

applied the first 2 patches

On Fri, Oct 30, 2020 at 10:42:25AM +0100, Alexandre Derumier wrote:
> following pve-common patch series
> 
> Alexandre Derumier (3):
>   Cgroups: use base PVE::CGroup and keep specific lxc code
>   use PVE::CGroup
>   cgroup: get_subdir: return cgroupv2 path for undef controller
> 
>  src/PVE/LXC.pm            |   7 +-
>  src/PVE/LXC/CGroup.pm     | 533 +-------------------------------------
>  src/lxc-pve-prestart-hook |   2 +-
>  3 files changed, 9 insertions(+), 533 deletions(-)
> 
> -- 
> 2.20.1