From 7cde4910a5adcab62506eff49f4500053464fc8a Mon Sep 17 00:00:00 2001 From: Michael Holzheu Date: Wed, 5 Aug 2015 11:23:53 +0200 Subject: [PATCH] s390/numa: make core to node mapping data dynamic The core to node mapping data consumes about 2 KB bss data. To save memory for the non-NUMA case, make the data dynamic. In addition change the "core_to_node" array from "int" to "s32" which saves 1 KB also for the NUMA case. Suggested-by: Heiko Carstens Signed-off-by: Michael Holzheu Signed-off-by: Martin Schwidefsky --- arch/s390/numa/mode_emu.c | 68 +++++++++++++++++++++++---------------- 1 file changed, 41 insertions(+), 27 deletions(-) diff --git a/arch/s390/numa/mode_emu.c b/arch/s390/numa/mode_emu.c index 646cd94cff2f..7de4e2f780d7 100644 --- a/arch/s390/numa/mode_emu.c +++ b/arch/s390/numa/mode_emu.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include #include "numa_mode.h" @@ -56,26 +57,24 @@ static unsigned long emu_size; * Node to core pinning information updates are protected by * "sched_domains_mutex". */ -/* Pinned core to node mapping */ -static int cores_to_node_id[CONFIG_NR_CPUS]; -/* Total number of pinned cores */ -static int cores_total; -/* Number of cores per node without extra cores */ -static int cores_per_node_target; -/* Number of cores pinned to node */ -static int cores_per_node[MAX_NUMNODES]; +static struct { + s32 to_node_id[CONFIG_NR_CPUS]; /* Pinned core to node mapping */ + int total; /* Total number of pinned cores */ + int per_node_target; /* Cores per node without extra cores */ + int per_node[MAX_NUMNODES]; /* Number of cores pinned to node */ +} *emu_cores; /* * Pin a core to a node */ static void pin_core_to_node(int core_id, int node_id) { - if (cores_to_node_id[core_id] == NODE_ID_FREE) { - cores_per_node[node_id]++; - cores_to_node_id[core_id] = node_id; - cores_total++; + if (emu_cores->to_node_id[core_id] == NODE_ID_FREE) { + emu_cores->per_node[node_id]++; + emu_cores->to_node_id[core_id] = node_id; + emu_cores->total++; } else { - WARN_ON(cores_to_node_id[core_id] != node_id); + WARN_ON(emu_cores->to_node_id[core_id] != node_id); } } @@ -84,7 +83,7 @@ static void pin_core_to_node(int core_id, int node_id) */ static int cores_pinned(struct toptree *node) { - return cores_per_node[node->id]; + return emu_cores->per_node[node->id]; } /* @@ -92,7 +91,7 @@ static int cores_pinned(struct toptree *node) */ static int core_pinned_to_node_id(struct toptree *core) { - return cores_to_node_id[core->id]; + return emu_cores->to_node_id[core->id]; } /* @@ -174,14 +173,15 @@ static void toptree_unify_tree(struct toptree *tree) /* * Find the best/nearest node for a given core and ensure that no node - * gets more than "cores_per_node_target + extra" cores. + * gets more than "emu_cores->per_node_target + extra" cores. */ static struct toptree *node_for_core(struct toptree *numa, struct toptree *core, int extra) { struct toptree *node, *node_best = NULL; - int dist_cur, dist_best; + int dist_cur, dist_best, cores_target; + cores_target = emu_cores->per_node_target + extra; dist_best = DIST_MAX; node_best = NULL; toptree_for_each(node, numa, NODE) { @@ -191,7 +191,7 @@ static struct toptree *node_for_core(struct toptree *numa, struct toptree *core, break; } /* Skip nodes that already have enough cores */ - if (cores_pinned(node) >= cores_per_node_target + extra) + if (cores_pinned(node) >= cores_target) continue; dist_cur = dist_node_to_core(node, core); if (dist_cur < dist_best) { @@ -225,11 +225,11 @@ static void toptree_to_numa_single(struct toptree *numa, struct toptree *phys, static void move_level_to_numa_node(struct toptree *node, struct toptree *phys, enum toptree_level level, bool perfect) { + int cores_free, cores_target = emu_cores->per_node_target; struct toptree *cur, *tmp; - int cores_free; toptree_for_each_safe(cur, tmp, phys, level) { - cores_free = cores_per_node_target - toptree_count(node, CORE); + cores_free = cores_target - toptree_count(node, CORE); if (perfect) { if (cores_free == toptree_count(cur, CORE)) toptree_move(cur, node); @@ -291,6 +291,20 @@ fail: panic("NUMA emulation could not allocate topology"); } +/* + * Allocate and initialize core to node mapping + */ +static void create_core_to_node_map(void) +{ + int i; + + emu_cores = kzalloc(sizeof(*emu_cores), GFP_KERNEL); + if (emu_cores == NULL) + panic("Could not allocate cores to node memory"); + for (i = 0; i < ARRAY_SIZE(emu_cores->to_node_id); i++) + emu_cores->to_node_id[i] = NODE_ID_FREE; +} + /* * Move cores from physical topology into NUMA target topology * and try to keep as much of the physical topology as possible. @@ -299,8 +313,10 @@ static struct toptree *toptree_to_numa(struct toptree *phys) { static int first = 1; struct toptree *numa; + int cores_total; - cores_per_node_target = (cores_total + cores_free(phys)) / emu_nodes; + cores_total = emu_cores->total + cores_free(phys); + emu_cores->per_node_target = cores_total / emu_nodes; numa = toptree_new(TOPTREE_ID_NUMA, emu_nodes); if (first) { toptree_to_numa_first(numa, phys); @@ -386,8 +402,8 @@ static void print_node_to_core_map(void) printk(KERN_DEBUG "NUMA node to core mapping\n"); for (nid = 0; nid < emu_nodes; nid++) { printk(KERN_DEBUG " node %3d: ", nid); - for (cid = 0; cid < ARRAY_SIZE(cores_to_node_id); cid++) { - if (cores_to_node_id[cid] == nid) + for (cid = 0; cid < ARRAY_SIZE(emu_cores->to_node_id); cid++) { + if (emu_cores->to_node_id[cid] == nid) printk(KERN_CONT "%d ", cid); } printk(KERN_CONT "\n"); @@ -404,6 +420,8 @@ static void emu_update_cpu_topology(void) { struct toptree *phys, *numa; + if (emu_cores == NULL) + create_core_to_node_map(); phys = toptree_from_topology(); numa = toptree_to_numa(phys); toptree_free(phys); @@ -443,12 +461,8 @@ static int emu_setup_nodes_adjust(int nodes) */ static void emu_setup(void) { - int i; - emu_size = emu_setup_size_adjust(emu_size); emu_nodes = emu_setup_nodes_adjust(emu_nodes); - for (i = 0; i < ARRAY_SIZE(cores_to_node_id); i++) - cores_to_node_id[i] = NODE_ID_FREE; pr_info("Creating %d nodes with memory stripe size %ld MB\n", emu_nodes, emu_size >> 20); }