From 1c09ab0d257317f97e8629a3d0c8713d6dd9de4c Mon Sep 17 00:00:00 2001 From: Yong Zhang Date: Tue, 28 Jun 2011 10:51:31 +0800 Subject: [PATCH] sched: Skip autogroup when looking for all rt sched groups Since commit ec514c48 ("sched: Fix rt_rq runtime leakage bug") 'cat /proc/sched_debug' will print data of root_task_group.rt_rq multiple times. This is because autogroup does not have its own rt group, instead rt group of autogroup is linked to root_task_group. So skip it when we are looking for all rt sched groups, and it will also save some noop operation against root_task_group when __disable_runtime()/__enable_runtime(). -v2: Based on Cheng Xu's idea which uses less code. Signed-off-by: Yong Zhang Cc: Mike Galbraith Cc: Cheng Xu Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/BANLkTi=87P3RoTF_UEtamNfc_XGxQXE__Q@mail.gmail.com Signed-off-by: Ingo Molnar --- kernel/sched_autogroup.h | 1 + kernel/sched_rt.c | 22 +++++++++++++++++----- 2 files changed, 18 insertions(+), 5 deletions(-) diff --git a/kernel/sched_autogroup.h b/kernel/sched_autogroup.h index 0557705..c2f0e72 100644 --- a/kernel/sched_autogroup.h +++ b/kernel/sched_autogroup.h @@ -13,6 +13,7 @@ struct autogroup { int nice; }; +static inline bool task_group_is_autogroup(struct task_group *tg); static inline struct task_group * autogroup_task_group(struct task_struct *p, struct task_group *tg); diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index b03cd89..97540f0 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -185,11 +185,23 @@ static inline u64 sched_rt_period(struct rt_rq *rt_rq) typedef struct task_group *rt_rq_iter_t; -#define for_each_rt_rq(rt_rq, iter, rq) \ - for (iter = list_entry_rcu(task_groups.next, typeof(*iter), list); \ - (&iter->list != &task_groups) && \ - (rt_rq = iter->rt_rq[cpu_of(rq)]); \ - iter = list_entry_rcu(iter->list.next, typeof(*iter), list)) +static inline struct task_group *next_task_group(struct task_group *tg) +{ + do { + tg = list_entry_rcu(tg->list.next, + typeof(struct task_group), list); + } while (&tg->list != &task_groups && task_group_is_autogroup(tg)); + + if (&tg->list == &task_groups) + tg = NULL; + + return tg; +} + +#define for_each_rt_rq(rt_rq, iter, rq) \ + for (iter = container_of(&task_groups, typeof(*iter), list); \ + (iter = next_task_group(iter)) && \ + (rt_rq = iter->rt_rq[cpu_of(rq)]);) static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq) { -- 2.7.4