mirror of
https://github.com/opencontainers/runc.git
synced 2026-07-11 06:03:57 +08:00
Kir Kolyshkin
52390d6804
This is somewhat radical approach to deal with kernel memory. Per-cgroup kernel memory limiting was always problematic. A few examples: - older kernels had bugs and were even oopsing sometimes (best example is RHEL7 kernel); - kernel is unable to reclaim the kernel memory so once the limit is hit a cgroup is toasted; - some kernel memory allocations don't allow failing. In addition to that, - users don't have a clue about how to set kernel memory limits (as the concept is much more complicated than e.g. [user] memory); - different kernels might have different kernel memory usage, which is sort of unexpected; - cgroup v2 do not have a [dedicated] kmem limit knob, and thus runc silently ignores kernel memory limits for v2; - kernel v5.4 made cgroup v1 kmem.limit obsoleted (see https://github.com/torvalds/linux/commit/0158115f702b). In view of all this, and as the runtime-spec lists memory.kernel and memory.kernelTCP as OPTIONAL, let's ignore kernel memory limits (for cgroup v1, same as we're already doing for v2). This should result in less bugs and better user experience. The only bad side effect from it might be that stat can show kernel memory usage as 0 (since the accounting is not enabled). [v2: add a warning in specconv that limits are ignored] Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
2.0 KiB
2.0 KiB
% runc-update "8"
NAME
runc update - update container resource constraints
SYNOPSIS
runc update [command options] <container-id>
DESCRIPTION
The data can be read from a file or the standard input, the accepted format is as follow (unchanged values can be omitted):
{ "memory": { "limit": 0, "reservation": 0, "swap": 0, "kernel": 0, "kernelTCP": 0 }, "cpu": { "shares": 0, "quota": 0, "period": 0, "realtimeRuntime": 0, "realtimePeriod": 0, "cpus": "", "mems": "" }, "blockIO": { "blkioWeight": 0 } }
Note: if data is to be read from a file or the standard input, all other options are ignored.
OPTIONS
--resources value, -r value path to the file containing the resources to update or '-' to read from the standard input
--blkio-weight value Specifies per cgroup weight, range is from 10 to 1000 (default: 0)
--cpu-period value CPU CFS period to be used for hardcapping (in usecs). 0 to use system default
--cpu-quota value CPU CFS hardcap limit (in usecs). Allowed cpu time in a given period
--cpu-rt-period value CPU realtime period to be used for hardcapping (in usecs). 0 to use system default
--cpu-rt-runtime value CPU realtime hardcap limit (in usecs). Allowed cpu time in a given period
--cpu-share value CPU shares (relative weight vs. other containers)
--cpuset-cpus value CPU(s) to use
--cpuset-mems value Memory node(s) to use
--memory value Memory limit (in bytes)
--memory-reservation value Memory reservation or soft_limit (in bytes)
--memory-swap value Total memory usage (memory + swap); set '-1' to enable unlimited swap
--pids-limit value Maximum number of pids allowed in the container (default: 0)
--l3-cache-schema The string of Intel RDT/CAT L3 cache schema
--mem-bw-schema The string of Intel RDT/MBA memory bandwidth schema