From be1e4e760d940c14d119bffef5eb007dfdf29046 Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Mon, 27 Jan 2014 17:03:48 -0500 Subject: [PATCH] sched/numa: Turn some magic numbers into #defines Cleanup suggested by Mel Gorman. Now the code contains some more hints on what statistics go where. Suggested-by: Mel Gorman Signed-off-by: Rik van Riel Acked-by: Mel Gorman Signed-off-by: Peter Zijlstra Cc: Chegu Vinod Link: http://lkml.kernel.org/r/1390860228-21539-10-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 34 +++++++++++++++++++++++++--------- 1 file changed, 25 insertions(+), 9 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index d5832c367d87..1f41b122198e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -896,6 +896,15 @@ struct numa_group { unsigned long faults[0]; }; +/* Shared or private faults. */ +#define NR_NUMA_HINT_FAULT_TYPES 2 + +/* Memory and CPU locality */ +#define NR_NUMA_HINT_FAULT_STATS (NR_NUMA_HINT_FAULT_TYPES * 2) + +/* Averaged statistics, and temporary buffers. */ +#define NR_NUMA_HINT_FAULT_BUCKETS (NR_NUMA_HINT_FAULT_STATS * 2) + pid_t task_numa_group_id(struct task_struct *p) { return p->numa_group ? p->numa_group->gid : 0; @@ -903,7 +912,7 @@ pid_t task_numa_group_id(struct task_struct *p) static inline int task_faults_idx(int nid, int priv) { - return 2 * nid + priv; + return NR_NUMA_HINT_FAULT_TYPES * nid + priv; } static inline unsigned long task_faults(struct task_struct *p, int nid) @@ -1509,7 +1518,7 @@ static void task_numa_placement(struct task_struct *p) unsigned long faults = 0, group_faults = 0; int priv, i; - for (priv = 0; priv < 2; priv++) { + for (priv = 0; priv < NR_NUMA_HINT_FAULT_TYPES; priv++) { long diff, f_diff, f_weight; i = task_faults_idx(nid, priv); @@ -1620,11 +1629,12 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags, INIT_LIST_HEAD(&grp->task_list); grp->gid = p->pid; /* Second half of the array tracks nids where faults happen */ - grp->faults_cpu = grp->faults + 2 * nr_node_ids; + grp->faults_cpu = grp->faults + NR_NUMA_HINT_FAULT_TYPES * + nr_node_ids; node_set(task_node(current), grp->active_nodes); - for (i = 0; i < 4*nr_node_ids; i++) + for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++) grp->faults[i] = p->numa_faults_memory[i]; grp->total_faults = p->total_numa_faults; @@ -1682,7 +1692,7 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags, double_lock(&my_grp->lock, &grp->lock); - for (i = 0; i < 4*nr_node_ids; i++) { + for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++) { my_grp->faults[i] -= p->numa_faults_memory[i]; grp->faults[i] += p->numa_faults_memory[i]; } @@ -1714,7 +1724,7 @@ void task_numa_free(struct task_struct *p) if (grp) { spin_lock(&grp->lock); - for (i = 0; i < 4*nr_node_ids; i++) + for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++) grp->faults[i] -= p->numa_faults_memory[i]; grp->total_faults -= p->total_numa_faults; @@ -1755,14 +1765,20 @@ void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags) /* Allocate buffer to track faults on a per-node basis */ if (unlikely(!p->numa_faults_memory)) { - int size = sizeof(*p->numa_faults_memory) * 4 * nr_node_ids; + int size = sizeof(*p->numa_faults_memory) * + NR_NUMA_HINT_FAULT_BUCKETS * nr_node_ids; - /* numa_faults and numa_faults_buffer share the allocation */ - p->numa_faults_memory = kzalloc(size * 2, GFP_KERNEL|__GFP_NOWARN); + p->numa_faults_memory = kzalloc(size, GFP_KERNEL|__GFP_NOWARN); if (!p->numa_faults_memory) return; BUG_ON(p->numa_faults_buffer_memory); + /* + * The averaged statistics, shared & private, memory & cpu, + * occupy the first half of the array. The second half of the + * array is for current counters, which are averaged into the + * first set by task_numa_placement. + */ p->numa_faults_cpu = p->numa_faults_memory + (2 * nr_node_ids); p->numa_faults_buffer_memory = p->numa_faults_memory + (4 * nr_node_ids); p->numa_faults_buffer_cpu = p->numa_faults_memory + (6 * nr_node_ids); -- 2.30.2