sched: Rename load-balancing fields
Commit-ID: ddcdf6e7d9919d139031fa2a6addd9544a9a833e Gitweb: http://git.kernel.org/tip/ddcdf6e7d9919d139031fa2a6addd9544a9a833e Author: Peter Zijlstra <[email protected]> AuthorDate: Wed, 22 Feb 2012 19:27:40 +0100 Committer: Ingo Molnar <[email protected]> CommitDate: Thu, 1 Mar 2012 10:51:23 +0100
sched: Rename load-balancing fields
s/env->this_/env->dst_/g
s/env->busiest_/env->src_/g
s/pull_task/move_task/g
Makes everything clearer.
Signed-off-by Peter Zijlstra <[email protected]>
Signed-off-by Ingo Molnar <[email protected]>
--- kernel/sched/fair.c | 118 ++++++++++++++++++++++++++------------------------- 1 files changed, 60 insertions(+), 58 deletions(-)
kernel/sched/fair.c +60 -58
@@ -2918,7 +2918,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_return ;/* -* This is possible from callers such as pull_task(), in which we +* This is possible from callers such as move_task(), in which we * unconditionally check_prempt_curr() after an enqueue (which may have * lead to a throttle). This both saves work and prevents false * next-buddy nomination below.
@@ -3084,17 +3084,37 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preempstatic unsigned long __read_mostly max_load_balance_interval =HZ /10 ; +#define LBF_ALL_PINNED 0x01 +#define LBF_NEED_BREAK 0x02/* clears into HAD_BREAK */ +#define LBF_HAD_BREAK 0x04 +#define LBF_HAD_BREAKS 0x0C/* count HAD_BREAKs overflows into ABORT */ +#define LBF_ABORT 0x10 + +struct lb_env { +struct sched_domain *sd; + +int src_cpu; +struct rq *src_rq; +struct cfs_rq *src_cfs_rq; + +int dst_cpu; +struct rq *dst_rq; + +enum cpu_idle_type idle; +unsigned long max_load_move; +unsigned int flags; +}; +/* -* pull_task - move a task from a remote runqueue to the local runqueue. +* move_task - move a task from one runqueue to another runqueue. * Both runqueues must be locked. */ -static void pull_task (struct rq *src_rq,struct task_struct *p, -struct rq *this_rq,int this_cpu) +static void move_task (struct task_struct *p,struct lb_env *env) { -deactivate_task (src_rq, p,0 ); -set_task_cpu (p, this_cpu); -activate_task (this_rq, p,0 ); -check_preempt_curr (this_rq, p,0 ); +deactivate_task (env->src_rq, p,0 ); +set_task_cpu (p, env->dst_cpu); +activate_task (env->dst_rq, p,0 ); +check_preempt_curr (env->dst_rq, p,0 ); }/*
@@ -3129,26 +3149,6 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)return delta < (s64 )sysctl_sched_migration_cost; } -#define LBF_ALL_PINNED 0x01 -#define LBF_NEED_BREAK 0x02/* clears into HAD_BREAK */ -#define LBF_HAD_BREAK 0x04 -#define LBF_HAD_BREAKS 0x0C/* count HAD_BREAKs overflows into ABORT */ -#define LBF_ABORT 0x10 - -struct lb_env { -struct sched_domain *sd; - -int this_cpu; -struct rq *this_rq; - -struct rq *busiest_rq; -struct cfs_rq *busiest_cfs_rq; - -enum cpu_idle_type idle; -unsigned long max_load_move; -unsigned int flags; -}; -/* * can_migrate_task - may task p from runqueue rq be migrated to this_cpu? */
@@ -3162,13 +3162,13 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env)* 2) cannot be migrated to this CPU due to cpus_allowed, or * 3) are cache-hot on their current CPU. */ -if (!cpumask_test_cpu (env->this_cpu,tsk_cpus_allowed (p))) { +if (!cpumask_test_cpu (env->dst_cpu,tsk_cpus_allowed (p))) {schedstat_inc (p, se.statistics.nr_failed_migrations_affine);return 0 ; } env->flags &= ~LBF_ALL_PINNED ; -if (task_running (env->busiest_rq, p)) { +if (task_running (env->src_rq, p)) {schedstat_inc (p, se.statistics.nr_failed_migrations_running);return 0 ; }
@@ -3179,7 +3179,7 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env)* 2) too many balance attempts have failed. */ - tsk_cache_hot =task_hot (p, env->busiest_rq->clock_task, env->sd); + tsk_cache_hot =task_hot (p, env->src_rq->clock_task, env->sd);if (!tsk_cache_hot || env->sd->nr_balance_failed > env->sd->cache_nice_tries) {#ifdef CONFIG_SCHEDSTATS
@@ -3210,20 +3210,20 @@ static int move_one_task(struct lb_env *env)struct task_struct *p, *n;struct cfs_rq *cfs_rq; -for_each_leaf_cfs_rq (env->busiest_rq, cfs_rq) { +for_each_leaf_cfs_rq (env->src_rq, cfs_rq) {list_for_each_entry_safe (p, n, &cfs_rq->tasks, se.group_node) {if (throttled_lb_pair (task_group (p), - env->busiest_rq->cpu, env->this_cpu)) + env->src_cpu, env->dst_cpu))break ;if (!can_migrate_task (p, env))continue ; -pull_task (env->busiest_rq, p, env->this_rq, env->this_cpu); +move_task (p, env);/* -* Right now, this is only the second place pull_task() -* is called, so we can safely collect pull_task() -* stats here rather than inside pull_task(). +* Right now, this is only the second place move_task() +* is called, so we can safely collect move_task() +* stats here rather than inside move_task(). */ schedstat_inc (env->sd, lb_gained[env->idle]);return 1 ;
@@ -3242,7 +3242,7 @@ static unsigned long balance_tasks(struct lb_env *env)if (env->max_load_move ==0 ) goto out; -list_for_each_entry_safe (p, n, &env->busiest_cfs_rq->tasks, se.group_node) { +list_for_each_entry_safe (p, n, &env->src_cfs_rq->tasks, se.group_node) {if (loops++ > sysctl_sched_nr_migrate) { env->flags |=LBF_NEED_BREAK ;break ;
@@ -3252,7 +3252,7 @@ static unsigned long balance_tasks(struct lb_env *env) !can_migrate_task(p, env))continue ; -pull_task (env->busiest_rq, p, env->this_rq, env->this_cpu); +move_task (p, env); pulled++; rem_load_move -= p->se.load.weight;
@@ -3277,9 +3277,9 @@ static unsigned long balance_tasks(struct lb_env *env) } out:/* -* Right now, this is one of only two places pull_task() is called, -* so we can safely collect pull_task() stats here rather than -* inside pull_task(). +* Right now, this is one of only two places move_task() is called, +* so we can safely collect move_task() stats here rather than +* inside move_task(). */ schedstat_add (env->sd, lb_gained[env->idle], pulled);
@@ -3372,11 +3372,11 @@ static unsigned long load_balance_fair(struct lb_env *env)long rem_load_move = env->max_load_move;rcu_read_lock (); -update_h_load (cpu_of (env->busiest_rq)); +update_h_load (cpu_of (env->src_rq)); -for_each_leaf_cfs_rq (env->busiest_rq, env->busiest_cfs_rq) { -unsigned long busiest_h_load = env->busiest_cfs_rq->h_load; -unsigned long busiest_weight = env->busiest_cfs_rq->load.weight; +for_each_leaf_cfs_rq (env->src_rq, env->src_cfs_rq) { +unsigned long busiest_h_load = env->src_cfs_rq->h_load; +unsigned long busiest_weight = env->src_cfs_rq->load.weight;u64 rem_load, moved_load;if (env->flags & (LBF_NEED_BREAK |LBF_ABORT ))
@@ -3385,12 +3385,12 @@ static unsigned long load_balance_fair(struct lb_env *env)/* * empty group or part of a throttled hierarchy */ -if (!env->busiest_cfs_rq->task_weight) +if (!env->src_cfs_rq->task_weight)continue ; -if (throttled_lb_pair (env->busiest_cfs_rq->tg, -cpu_of (env->busiest_rq), - env->this_cpu)) +if (throttled_lb_pair (env->src_cfs_rq->tg, +cpu_of (env->src_rq), + env->dst_cpu))continue ; rem_load = (u64 )rem_load_move * busiest_weight;
@@ -3420,7 +3420,7 @@ static inline void update_shares(int cpu)static unsigned long load_balance_fair (struct lb_env *env) { - env->busiest_cfs_rq = &env->busiest_rq->cfs; + env->src_cfs_rq = &env->src_rq->cfs;return balance_tasks (env); }#endif
@@ -3451,7 +3451,7 @@ static int move_tasks(struct lb_env *env)* kernels will stop after the first task is pulled to minimize * the critical section. */ -if (env->idle ==CPU_NEWLY_IDLE && env->this_rq->nr_running) { +if (env->idle ==CPU_NEWLY_IDLE && env->dst_rq->nr_running) { env->flags |=LBF_ABORT ;break ; }
@@ -4461,8 +4461,8 @@ static int load_balance(int this_cpu, struct rq *this_rq,struct lb_env env = { .sd = sd, - .this_cpu = this_cpu, - .this_rq = this_rq, + .dst_cpu = this_cpu, + .dst_rq = this_rq, .idle = idle, };
@@ -4502,7 +4502,8 @@ redo:*/ env.flags |=LBF_ALL_PINNED ; env.max_load_move = imbalance; - env.busiest_rq = busiest; + env.src_cpu = busiest->cpu; + env.src_rq = busiest;local_irq_save (flags);double_rq_lock (this_rq, busiest);
@@ -4722,9 +4723,10 @@ static int active_load_balance_cpu_stop(void *data)if (likely (sd)) {struct lb_env env = { .sd = sd, - .this_cpu = target_cpu, - .this_rq = target_rq, - .busiest_rq = busiest_rq, + .dst_cpu = target_cpu, + .dst_rq = target_rq, + .src_cpu = busiest_rq->cpu, + .src_rq = busiest_rq, .idle =CPU_IDLE , };