Messages in this thread Patch in this message | | | From | Vaidyanathan Srinivasan <> | Subject | [RFC PATCH v2 2/5] sched: calculate statistics for current load balance domain | Date | Thu, 09 Oct 2008 17:39:34 +0530 |
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Add data structures and function to collect per sched domain statistics required for load balance decision.
Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> ---
kernel/sched.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 51 insertions(+), 0 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c index ab77937..cfd83d9 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3178,6 +3178,57 @@ int get_group_loads(struct sched_group *group, int this_cpu, return need_balance; } +/* Struct to hold sched domain level loads */ + +struct sd_loads { + struct sched_domain *sd; + unsigned long load; /* Total decay load */ + unsigned long cpu_power; /* Total cpu_power */ + unsigned long max_load; /* load of busiest group */ + unsigned long load_per_cpu; /* Decay load per cpu in this sd + * (load/cpu_power) + */ + struct group_loads local; /* this_cpu's group, + * need to pull from busiest + */ + struct group_loads busiest; /* Candidate group to pull */ + /* sched_mc power_save balance groups */ + struct group_loads min_load_group; /* Group that is least loaded and + * can fit the tasks into the + * leader group + */ + struct group_loads power_save_leader_group; /* Group that is almost + * full but can still pull + * tasks from + * min_load_group + */ +}; + +/* Function to aggregate per group loads to sched domain loads */ + +void update_sd_loads(struct sd_loads *sdl, struct group_loads *gl) +{ + int group_capacity = gl->group->__cpu_power / SCHED_LOAD_SCALE; + sdl->max_load = 0; + + if (gl->local_group) + sdl->local = *gl; + else { + sdl->load += gl->load; + sdl->cpu_power += gl->group->__cpu_power; + + + /* Find the busiest */ + if (gl->load > sdl->max_load && + (gl->nr_running > group_capacity || + gl->group_imbalance)) { + + sdl->max_load = gl->load; + sdl->busiest = *gl; + } + } +} + /* * find_busiest_group finds and returns the busiest CPU group within the * domain. It calculates and returns the amount of weighted load which
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