Comment 4 for bug 1348688

After updating to that kernel (under 14.04), the problem is not fixed.

$ uname -a
Linux kit1 3.19.0-031900rc4-generic #201501112135 SMP Sun Jan 11 21:36:48 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

* The LXC instance still does not start if the <memtune><swap_hard_limit unit='KiB'>131072</swap_hard_limit></memtune> setting is included.

$ virsh -c lxc: start gold-lxc-20140717
error: Failed to start domain gold-lxc-20140717
error: internal error: guest failed to start: Unable to write to '/sys/fs/cgroup/memory/machine/gold-lxc-20140717.libvirt-lxc/memory.memsw.limit_in_bytes': No such file or directory

$ ls /sys/fs/cgroup/memory/machine/gold-lxc-20140717.libvirt-lxc/
cgroup.clone_children memory.kmem.tcp.failcnt memory.oom_control
cgroup.event_control memory.kmem.tcp.limit_in_bytes memory.pressure_level
cgroup.procs memory.kmem.tcp.max_usage_in_bytes memory.soft_limit_in_bytes
memory.failcnt memory.kmem.tcp.usage_in_bytes memory.stat
memory.force_empty memory.kmem.usage_in_bytes memory.swappiness
memory.kmem.failcnt memory.limit_in_bytes memory.usage_in_bytes
memory.kmem.limit_in_bytes memory.max_usage_in_bytes memory.use_hierarchy
memory.kmem.max_usage_in_bytes memory.move_charge_at_immigrate notify_on_release
memory.kmem.slabinfo memory.numa_stat tasks

(Note it does not include memory.memsw.limit_in_bytes)

* After reverting to kernel 3.13.0-43 and doing the same lxc start which fails in the same way:

$ ls /sys/fs/cgroup/memory/machine/gold-lxc-20140717.libvirt-lxc/
cgroup.clone_children memory.kmem.tcp.failcnt memory.oom_control
cgroup.event_control memory.kmem.tcp.limit_in_bytes memory.pressure_level
cgroup.procs memory.kmem.tcp.max_usage_in_bytes memory.soft_limit_in_bytes
memory.failcnt memory.kmem.tcp.usage_in_bytes memory.stat
memory.force_empty memory.kmem.usage_in_bytes memory.swappiness
memory.kmem.failcnt memory.limit_in_bytes memory.usage_in_bytes
memory.kmem.limit_in_bytes memory.max_usage_in_bytes memory.use_hierarchy
memory.kmem.max_usage_in_bytes memory.move_charge_at_immigrate notify_on_release
memory.kmem.slabinfo memory.numa_stat tasks

Looks identical to me.