Just CC'ing the Debian LXC maintainer and the upstream LXC mailing lists. I guess they may find relevant this bug.
https://bugs.debian.org/793372 Regards. On 23/07/15 13:57, Pablo Abelenda wrote: > Package: systemd > Version: 215-17+deb8u1 > Severity: important > > Dear Maintainer, > > I have been checking on LXC for a while. I wanted to acquaint with the > containers management, specifically with the resources limitation > capabilities. > > I have created, configured and destroyed several containers. The issue > comes when I try to limit the memory usage. I have added this option to > the grub defaults: > > cgroup_enable=memory > > This allowed me to start a container with options configured such as > this: > > lxc.cgroup.memory.limit_in_bytes = 1024M > lxc.cgroup.memory.memsw.limit_in_bytes = 1200M > > The thing is that when I try to use more than 1200 MB of memory, inside > the container, I actually can. I have used a very simply script I found > on someone page to test the memory allocation capabilities. > > ######################################## > memory_allocation.py > ######################################## > #!/usr/bin/env python > import sys > import time > > if len(sys.argv) != 2: > print "usage: fillmem <number-of-megabytes>" > sys.exit() > > count = int(sys.argv[1]) > > megabyte = (0,) * (1024 * 1024 / 8) > > data = megabyte * count > > while True: > time.sleep(1) > ######################################## > > I have tried to isolate the problem, focusing on some missing LXC or > cgroups configuration. Let me add the trace: > > First, I have created a new control group, outside the LXC stuff: > > cgcreate -g memory:/bmalloc1gb > echo $(( 1024 * 1024 * 1024 ))|tee > /sys/fs/cgroup/memory/bmalloc1gb/memory.limit_in_bytes > echo $(( 1200 * 1024 * 1024 ))|tee > /sys/fs/cgroup/memory/bmalloc1gb/memory.memsw.limit_in_bytes > cgexec -g memory:/bmalloc1gb bash > python memory_allocation.py 2000 [killed] > > When I run the script on this environment, the memory allocation did not > went far from this 1200 MB, which is what I need. > > Second, I have joined the LXC cgroup, to try the very same as above: > > cgexec -g memory:lxc/test bash > python memory_allocation.py 2000 [killed] > > This two tests made me point to LXC, but after some internet digging I > found this: > > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=777601 > > In this bug report, which is not exactly the same as this one, the > reporter states this: > > "I also tested something which may be another problem (so another ticket) > but the memory and swap limitation doesn't work at all :-(...with or > without this bug. I can't tell if it's linked or not. > I tested cpu pinning and it works like a charm. The issue seems related > to memory and swap only." > > After this income information, I have switched back both the host and > the container, to sysvinit. With the systems booted on sysvinit, the > memory limitation is working as it is expected. > > Let me add the whole container configuration for your reference: > > lxc.cgroup.cpuset.cpus = 0,1 > lxc.cgroup.cpu.shares = 256 > lxc.cgroup.blkio.weight = 500 > lxc.cgroup.memory.limit_in_bytes = 1024M > lxc.cgroup.memory.memsw.limit_in_bytes = 1200M > lxc.network.type = veth > lxc.network.flags = up > lxc.network.link = br0 > lxc.network.name = eth0 > lxc.rootfs = /dev/vg/test > lxc.start.auto = 1 > lxc.include = /usr/share/lxc/config/debian.common.conf > lxc.mount = /var/lib/lxc/test/fstab > lxc.utsname = test > lxc.arch = amd64 > lxc.autodev = 1 > > Thanks for your consideration. > > Best regards. > > > -- Package-specific info: > > -- System Information: > Debian Release: 8.1 > APT prefers stable-updates > APT policy: (500, 'stable-updates'), (500, 'stable') > Architecture: amd64 (x86_64) > > Kernel: Linux 3.16.0-4-amd64 (SMP w/4 CPU cores) > Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8) > Shell: /bin/sh linked to /bin/dash > Init: systemd (via /run/systemd/system) > > Versions of packages systemd depends on: > ii acl 2.2.52-2 > ii adduser 3.113+nmu3 > ii initscripts 2.88dsf-59 > ii libacl1 2.2.52-2 > ii libaudit1 1:2.4-1+b1 > ii libblkid1 2.25.2-6 > ii libc6 2.19-18 > ii libcap2 1:2.24-8 > ii libcap2-bin 1:2.24-8 > ii libcryptsetup4 2:1.6.6-5 > ii libgcrypt20 1.6.3-2 > ii libkmod2 18-3 > ii liblzma5 5.1.1alpha+20120614-2+b3 > ii libpam0g 1.1.8-3.1 > ii libselinux1 2.3-2 > ii libsystemd0 215-17+deb8u1 > ii mount 2.25.2-6 > ii sysv-rc 2.88dsf-59 > ii udev 215-17+deb8u1 > ii util-linux 2.25.2-6 > > Versions of packages systemd recommends: > ii dbus 1.8.18-0+deb8u1 > ii libpam-systemd 215-17+deb8u1 > > Versions of packages systemd suggests: > pn systemd-ui <none> > > -- no debconf information > > >
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