1. List of topics 1. Control loops in userspace 2. Hierarchical
Cgroup support in userland 3. Efficient utilization by
overcommitment 4. dcache management 5. Memory controller
improvements 6. Checkpoint/restart in the userspace 7. Container in
a file 8. Proc fs virtualization 9. Entering a container 10.vzctl
for LXC 11.Extending CPU accounting stats
2. dcache mgmt 1/2: problems Problem 1 the number of dentries
grows uncontrollable Entries can be pinned with low effort, leading
to all memory being used and unreclaimable Leading to system being
unresponsive/stuck Problem 2 Unfair dentry cache usage distribution
among containers
3. dcache mgmt 2/2: Solution Account for and limit dcache usage
per (smth) Currently (smth) is superblock Shrink dcache per (smth)
once limit it hit
4. checkpoint-restore 1/3 Checkpoint: freeze task(s) with
freezer cgroup read tasks creds via /proc some patches extending
kernel API required read tasks regs with PTRACE dump tasks mem with
PTRASE_SEIZE (new)
5. checkpoint-restore 2/3 Restore: Fork task tree CLONE_SETPID
required each task restores its creds uid/gid open files
capabilities etc. each task calls execve() on an image ELF binfmt
handler extension required
7. Container in a file 1/2 Currently containers' files reside
on host partition and tasks work in plain chroot Problems: extX
journal is performance bottleneck hackish live migration (rsync)
not effective management (tons of small files)
8. Container in a file 2/2 Solution loop-like block device
Parallels implementation block device, that remaps bio-s with FS
bmap call Possible implementation DM extension block map provided
by userspace block map got from FS bmap call
