Re: NUMA aware slab allocator V3

Christoph Lameter
2005-05-17T00:15:57Z

On Mon, 16 May 2005, Martin J. Bligh wrote:

> > Yeah, makes sense for the NUMA aware slab allocator to depend on
> > CONFIG_NUMA.
>
> Andy confirmed offline that this is really CONFIG_NEED_MULTIPLE_PGDATS,
> and is just named wrong.

Hmmm.. In this case it may be necessary for the slab allocator to
determine what is the proper number of NUMA nodes. I do not really like it
but it seems that we need the following patch to rectify the situation.

Index: linux-2.6.12-rc4/mm/slab.c
===================================================================
--- linux-2.6.12-rc4.orig/mm/slab.c 2005-05-16 16:58:44.000000000 -0700
+++ linux-2.6.12-rc4/mm/slab.c 2005-05-16 17:04:11.000000000 -0700
@@ -112,10 +112,12 @@
* there is only a single node if CONFIG_NUMA is not set. Remove this check
* after the situation has stabilized.
*/
-#ifndef CONFIG_NUMA
-#if MAX_NUMNODES != 1
-#error "Broken Configuration: CONFIG_NUMA not set but MAX_NUMNODES !=1 !!"
-#endif
+#ifdef CONFIG_NUMA
+#define NUMA_NODES MAX_NUMNODES
+#define NUMA_NODE_ID numa_node_id()
+#else
+#define NUMA_NODES 1
+#define NUMA_NODE_ID 0
#endif

/*
@@ -311,7 +313,7 @@
/*
* Need this for bootstrapping a per node allocator.
*/
-#define NUM_INIT_LISTS (2 + MAX_NUMNODES)
+#define NUM_INIT_LISTS (2 + NUMA_NODES)
struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS];
#define CACHE_CACHE 0
#define SIZE_AC 1
@@ -385,7 +387,7 @@
} while (0)

#define list3_data(cachep) \
- ((cachep->nodelists[numa_node_id()]))
+ ((cachep->nodelists[NUMA_NODE_ID]))

/* NUMA: per-node */
#define list3_data_ptr(cachep, ptr) \
@@ -405,7 +407,7 @@
unsigned int shared;
unsigned int objsize;
/* 2) touched by every alloc & free from the backend */
- struct kmem_list3 *nodelists[MAX_NUMNODES];
+ struct kmem_list3 *nodelists[NUMA_NODES];
unsigned int flags; /* constant flags */
unsigned int num; /* # of objs per slab */
spinlock_t spinlock;
@@ -792,7 +794,7 @@
static inline struct array_cache **alloc_alien_cache(int cpu, int limit)
{
struct array_cache **ac_ptr;
- int memsize = sizeof(void*)*MAX_NUMNODES;
+ int memsize = sizeof(void*)*NUMA_NODES;
int node = cpu_to_node(cpu);
int i;

@@ -800,7 +802,7 @@
limit = 12;
ac_ptr = kmalloc_node(memsize, GFP_KERNEL, node);
if (ac_ptr) {
- for (i = 0; i < MAX_NUMNODES; i++) {
+ for (i = 0; i < NUMA_NODES; i++) {
if (i == node) {
ac_ptr[i] = NULL;
continue;
@@ -823,7 +825,7 @@

if (!ac_ptr)
return;
- for (i = 0; i < MAX_NUMNODES; i++)
+ for (i = 0; i < NUMA_NODES; i++)
kfree(ac_ptr[i]);

kfree(ac_ptr);
@@ -847,7 +849,7 @@
struct array_cache *ac;
unsigned long flags;

- for (i = 0; i < MAX_NUMNODES; i++) {
+ for (i = 0; i < NUMA_NODES; i++) {
ac = l3->alien[i];
if (ac) {
spin_lock_irqsave(&ac->lock, flags);
@@ -1028,7 +1030,7 @@

for (i = 0; i < NUM_INIT_LISTS; i++) {
LIST3_INIT(&initkmem_list3[i]);
- if (i < MAX_NUMNODES)
+ if (i < NUMA_NODES)
cache_cache.nodelists[i] = NULL;
}

@@ -1065,7 +1067,7 @@
list_add(&cache_cache.next, &cache_chain);
cache_cache.colour_off = cache_line_size();
cache_cache.array[smp_processor_id()] = &initarray_cache.cache;
- cache_cache.nodelists[numa_node_id()] = &initkmem_list3[CACHE_CACHE];
+ cache_cache.nodelists[NUMA_NODE_ID] = &initkmem_list3[CACHE_CACHE];

cache_cache.objsize = ALIGN(cache_cache.objsize, cache_line_size());

@@ -1154,7 +1156,7 @@
int node;
/* Replace the static kmem_list3 structures for the boot cpu */
init_list(&cache_cache, &initkmem_list3[CACHE_CACHE],
- numa_node_id());
+ NUMA_NODE_ID);

for_each_online_node(node) {
init_list(malloc_sizes[INDEX_L3].cs_cachep,
@@ -1163,7 +1165,7 @@
if (INDEX_AC != INDEX_L3) {
init_list(malloc_sizes[INDEX_AC].cs_cachep,
&initkmem_list3[SIZE_AC],
- numa_node_id());
+ NUMA_NODE_ID);
}
}

@@ -1778,7 +1780,7 @@
set_up_list3s(cachep);
g_cpucache_up = PARTIAL_L3;
} else {
- cachep->nodelists[numa_node_id()] =
+ cachep->nodelists[NUMA_NODE_ID] =
&initkmem_list3[SIZE_AC];
g_cpucache_up = PARTIAL_AC;
}
@@ -1791,18 +1793,18 @@
set_up_list3s(cachep);
g_cpucache_up = PARTIAL_L3;
} else {
- cachep->nodelists[numa_node_id()] =
+ cachep->nodelists[NUMA_NODE_ID] =
kmalloc(sizeof(struct kmem_list3),
GFP_KERNEL);
- LIST3_INIT(cachep->nodelists[numa_node_id()]);
+ LIST3_INIT(cachep->nodelists[NUMA_NODE_ID]);
}
}
- cachep->nodelists[numa_node_id()]->next_reap =
+ cachep->nodelists[NUMA_NODE_ID]->next_reap =
jiffies + REAPTIMEOUT_LIST3 +
((unsigned long)cachep)%REAPTIMEOUT_LIST3;

BUG_ON(!ac_data(cachep));
- BUG_ON(!cachep->nodelists[numa_node_id()]);
+ BUG_ON(!cachep->nodelists[NUMA_NODE_ID]);
ac_data(cachep)->avail = 0;
ac_data(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
ac_data(cachep)->batchcount = 1;
@@ -1986,7 +1988,7 @@
drain_cpu_caches(cachep);

check_irq_on();
- for (i = 0; i < MAX_NUMNODES; i++) {
+ for (i = 0; i < NUMA_NODES; i++) {
l3 = cachep->nodelists[i];
if (l3) {
spin_lock_irq(&l3->list_lock);
@@ -2068,7 +2070,7 @@
kfree(cachep->array[i]);

/* NUMA: free the list3 structures */
- for (i = 0; i < MAX_NUMNODES; i++) {
+ for (i = 0; i < NUMA_NODES; i++) {
if ((l3 = cachep->nodelists[i])) {
kfree(l3->shared);
#ifdef CONFIG_NUMA
@@ -2482,7 +2484,7 @@

if (unlikely(!ac->avail)) {
int x;
- x = cache_grow(cachep, flags, numa_node_id());
+ x = cache_grow(cachep, flags, NUMA_NODE_ID);

// cache_grow can reenable interrupts, then ac could change.
ac = ac_data(cachep);
@@ -2786,7 +2788,7 @@
{
struct slab *slabp;
slabp = GET_PAGE_SLAB(virt_to_page(objp));
- if (unlikely(slabp->nodeid != numa_node_id())) {
+ if (unlikely(slabp->nodeid != NUMA_NODE_ID)) {
struct array_cache *alien = NULL;
int nodeid = slabp->nodeid;
struct kmem_list3 *l3 = list3_data(cachep);
@@ -2896,7 +2898,7 @@
unsigned long save_flags;
void *ptr;

- if (nodeid == numa_node_id() || nodeid == -1)
+ if (nodeid == NUMA_NODE_ID || nodeid == -1)
return __cache_alloc(cachep, flags);

cache_alloc_debugcheck_before(cachep, flags);
@@ -3437,7 +3439,7 @@
spin_lock_irq(&l3->list_lock);

drain_array_locked(searchp, ac_data(searchp), 0,
- numa_node_id());
+ NUMA_NODE_ID);

#if DEBUG
if (time_before(searchp->redzonetest, jiffies)) {
@@ -3452,7 +3454,7 @@

if (l3->shared)
drain_array_locked(searchp, l3->shared, 0,
- numa_node_id());
+ NUMA_NODE_ID);

if (l3->free_touched) {
l3->free_touched = 0;