On 06/15/2011 01:24 AM, Wen Congyang wrote:
I need this feature immediately after CFS bandwidth patchset is merged into upstream kernel. So I prepare this patchset, and post it here for reviewing before CFS bandwidth is merged into upstream kernel.
quota is an optional attribute specified in microseconds not a percentage of period.
TODO: 1. quota should be in the range [1000, 18446744073709551(2^64/1000)] or less than 0. But I only limit it less or equal than 2^64/1000. Does anyone have a better way to limit quota?
What are the semantics of quota < 0, of quota == 0? How are you storing such a large signed integer in the kernel? I will guess that any value less than 0 means: no limit, and 0 means: no quota (ie. the cgroup cannot run on the cpu). I am not sure what the libvirt convention for dealing with a situation like this is. I think you have two options: 1) override an invalid value (ie. 1) to represent the case (n < 0) or, 2) use a struct to represent the quota: struct _virCfsQuota { unsigned long long val; int unlimited; }; When the quota is unlimited, .unlimited == 1 and val is undefined. Otherwise, the quota is in val.
Wen Congyang (5): cgroup: Implement cpu.cfs_period_us and cpu.cfs_quota_us tuning API Update XML Schema for new entries qemu: Implement period and quota tunable XML configuration and parsing. qemu: Implement cfs_period and cfs_quota's modification doc: Add documentation for new cputune elements period and quota
docs/formatdomain.html.in | 19 +++ docs/schemas/domain.rng | 25 ++++- src/conf/domain_conf.c | 20 +++- src/conf/domain_conf.h | 2 + src/libvirt_private.syms | 4 + src/qemu/qemu_cgroup.c | 43 +++++- src/qemu/qemu_driver.c | 162 +++++++++++++++++++---- src/util/cgroup.c | 81 +++++++++++- src/util/cgroup.h | 6 + tests/qemuxml2argvdata/qemuxml2argv-cputune.xml | 2 + 10 files changed, 328 insertions(+), 36 deletions(-)
-- Adam Litke IBM Linux Technology Center