Messages in this thread Patch in this message | | | From | Frederic Weisbecker <> | Subject | [PATCH 02/10] cgroups: New resource counter inheritance API | Date | Mon, 3 Oct 2011 21:07:04 +0200 |
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Provide an API to inherit a counter value from a parent. This can be useful to implement cgroup.clone_children on a resource counter.
Still the resources of the children are limited by those of the parent, so this is only to provide a default setting behaviour when clone_children is set.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Menage <paul@paulmenage.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Aditya Kali <adityakali@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Tim Hockin <thockin@hockin.org> Cc: Tejun Heo <tj@kernel.org> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Containers <containers@lists.linux-foundation.org> --- include/linux/res_counter.h | 2 ++ kernel/res_counter.c | 18 ++++++++++++++++++ 2 files changed, 20 insertions(+), 0 deletions(-)
diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h index 1b3fe05..109d118 100644 --- a/include/linux/res_counter.h +++ b/include/linux/res_counter.h @@ -84,6 +84,8 @@ int res_counter_write(struct res_counter *counter, int member, void res_counter_write_u64(struct res_counter *counter, int member, u64 val); +void res_counter_inherit(struct res_counter *counter, int member); + /* * the field descriptors. one for each member of res_counter */ diff --git a/kernel/res_counter.c b/kernel/res_counter.c index 0faafcc..37abf4e 100644 --- a/kernel/res_counter.c +++ b/kernel/res_counter.c @@ -202,3 +202,21 @@ int res_counter_write(struct res_counter *counter, int member, return 0; } + +/* + * Simple inheritance implementation to get the same value + * than a parent. However this doesn't enforce the child value + * to be always below the one of the parent. But the child is + * subject to its parent limitation anyway. + */ +void res_counter_inherit(struct res_counter *counter, int member) +{ + struct res_counter *parent; + unsigned long long val; + + parent = counter->parent; + if (parent) { + val = res_counter_read_u64(parent, member); + res_counter_write_u64(counter, member, val); + } +} -- 1.7.5.4
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