#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/cpu.h>
-#include <linux/sort.h>
-
-static void irq_spread_init_one(struct cpumask *irqmsk, struct cpumask *nmsk,
- unsigned int cpus_per_vec)
-{
- const struct cpumask *siblmsk;
- int cpu, sibl;
-
- for ( ; cpus_per_vec > 0; ) {
- cpu = cpumask_first(nmsk);
-
- /* Should not happen, but I'm too lazy to think about it */
- if (cpu >= nr_cpu_ids)
- return;
-
- cpumask_clear_cpu(cpu, nmsk);
- cpumask_set_cpu(cpu, irqmsk);
- cpus_per_vec--;
-
- /* If the cpu has siblings, use them first */
- siblmsk = topology_sibling_cpumask(cpu);
- for (sibl = -1; cpus_per_vec > 0; ) {
- sibl = cpumask_next(sibl, siblmsk);
- if (sibl >= nr_cpu_ids)
- break;
- if (!cpumask_test_and_clear_cpu(sibl, nmsk))
- continue;
- cpumask_set_cpu(sibl, irqmsk);
- cpus_per_vec--;
- }
- }
-}
-
-static cpumask_var_t *alloc_node_to_cpumask(void)
-{
- cpumask_var_t *masks;
- int node;
-
- masks = kcalloc(nr_node_ids, sizeof(cpumask_var_t), GFP_KERNEL);
- if (!masks)
- return NULL;
-
- for (node = 0; node < nr_node_ids; node++) {
- if (!zalloc_cpumask_var(&masks[node], GFP_KERNEL))
- goto out_unwind;
- }
-
- return masks;
-
-out_unwind:
- while (--node >= 0)
- free_cpumask_var(masks[node]);
- kfree(masks);
- return NULL;
-}
-
-static void free_node_to_cpumask(cpumask_var_t *masks)
-{
- int node;
-
- for (node = 0; node < nr_node_ids; node++)
- free_cpumask_var(masks[node]);
- kfree(masks);
-}
-
-static void build_node_to_cpumask(cpumask_var_t *masks)
-{
- int cpu;
-
- for_each_possible_cpu(cpu)
- cpumask_set_cpu(cpu, masks[cpu_to_node(cpu)]);
-}
-
-static int get_nodes_in_cpumask(cpumask_var_t *node_to_cpumask,
- const struct cpumask *mask, nodemask_t *nodemsk)
-{
- int n, nodes = 0;
-
- /* Calculate the number of nodes in the supplied affinity mask */
- for_each_node(n) {
- if (cpumask_intersects(mask, node_to_cpumask[n])) {
- node_set(n, *nodemsk);
- nodes++;
- }
- }
- return nodes;
-}
-
-struct node_vectors {
- unsigned id;
-
- union {
- unsigned nvectors;
- unsigned ncpus;
- };
-};
-
-static int ncpus_cmp_func(const void *l, const void *r)
-{
- const struct node_vectors *ln = l;
- const struct node_vectors *rn = r;
-
- return ln->ncpus - rn->ncpus;
-}
-
-/*
- * Allocate vector number for each node, so that for each node:
- *
- * 1) the allocated number is >= 1
- *
- * 2) the allocated numbver is <= active CPU number of this node
- *
- * The actual allocated total vectors may be less than @numvecs when
- * active total CPU number is less than @numvecs.
- *
- * Active CPUs means the CPUs in '@cpu_mask AND @node_to_cpumask[]'
- * for each node.
- */
-static void alloc_nodes_vectors(unsigned int numvecs,
- cpumask_var_t *node_to_cpumask,
- const struct cpumask *cpu_mask,
- const nodemask_t nodemsk,
- struct cpumask *nmsk,
- struct node_vectors *node_vectors)
-{
- unsigned n, remaining_ncpus = 0;
-
- for (n = 0; n < nr_node_ids; n++) {
- node_vectors[n].id = n;
- node_vectors[n].ncpus = UINT_MAX;
- }
-
- for_each_node_mask(n, nodemsk) {
- unsigned ncpus;
-
- cpumask_and(nmsk, cpu_mask, node_to_cpumask[n]);
- ncpus = cpumask_weight(nmsk);
-
- if (!ncpus)
- continue;
- remaining_ncpus += ncpus;
- node_vectors[n].ncpus = ncpus;
- }
-
- numvecs = min_t(unsigned, remaining_ncpus, numvecs);
-
- sort(node_vectors, nr_node_ids, sizeof(node_vectors[0]),
- ncpus_cmp_func, NULL);
-
- /*
- * Allocate vectors for each node according to the ratio of this
- * node's nr_cpus to remaining un-assigned ncpus. 'numvecs' is
- * bigger than number of active numa nodes. Always start the
- * allocation from the node with minimized nr_cpus.
- *
- * This way guarantees that each active node gets allocated at
- * least one vector, and the theory is simple: over-allocation
- * is only done when this node is assigned by one vector, so
- * other nodes will be allocated >= 1 vector, since 'numvecs' is
- * bigger than number of numa nodes.
- *
- * One perfect invariant is that number of allocated vectors for
- * each node is <= CPU count of this node:
- *
- * 1) suppose there are two nodes: A and B
- * ncpu(X) is CPU count of node X
- * vecs(X) is the vector count allocated to node X via this
- * algorithm
- *
- * ncpu(A) <= ncpu(B)
- * ncpu(A) + ncpu(B) = N
- * vecs(A) + vecs(B) = V
- *
- * vecs(A) = max(1, round_down(V * ncpu(A) / N))
- * vecs(B) = V - vecs(A)
- *
- * both N and V are integer, and 2 <= V <= N, suppose
- * V = N - delta, and 0 <= delta <= N - 2
- *
- * 2) obviously vecs(A) <= ncpu(A) because:
- *
- * if vecs(A) is 1, then vecs(A) <= ncpu(A) given
- * ncpu(A) >= 1
- *
- * otherwise,
- * vecs(A) <= V * ncpu(A) / N <= ncpu(A), given V <= N
- *
- * 3) prove how vecs(B) <= ncpu(B):
- *
- * if round_down(V * ncpu(A) / N) == 0, vecs(B) won't be
- * over-allocated, so vecs(B) <= ncpu(B),
- *
- * otherwise:
- *
- * vecs(A) =
- * round_down(V * ncpu(A) / N) =
- * round_down((N - delta) * ncpu(A) / N) =
- * round_down((N * ncpu(A) - delta * ncpu(A)) / N) >=
- * round_down((N * ncpu(A) - delta * N) / N) =
- * cpu(A) - delta
- *
- * then:
- *
- * vecs(A) - V >= ncpu(A) - delta - V
- * =>
- * V - vecs(A) <= V + delta - ncpu(A)
- * =>
- * vecs(B) <= N - ncpu(A)
- * =>
- * vecs(B) <= cpu(B)
- *
- * For nodes >= 3, it can be thought as one node and another big
- * node given that is exactly what this algorithm is implemented,
- * and we always re-calculate 'remaining_ncpus' & 'numvecs', and
- * finally for each node X: vecs(X) <= ncpu(X).
- *
- */
- for (n = 0; n < nr_node_ids; n++) {
- unsigned nvectors, ncpus;
-
- if (node_vectors[n].ncpus == UINT_MAX)
- continue;
-
- WARN_ON_ONCE(numvecs == 0);
-
- ncpus = node_vectors[n].ncpus;
- nvectors = max_t(unsigned, 1,
- numvecs * ncpus / remaining_ncpus);
- WARN_ON_ONCE(nvectors > ncpus);
-
- node_vectors[n].nvectors = nvectors;
-
- remaining_ncpus -= ncpus;
- numvecs -= nvectors;
- }
-}
-
-static int __irq_build_affinity_masks(unsigned int startvec,
- unsigned int numvecs,
- unsigned int firstvec,
- cpumask_var_t *node_to_cpumask,
- const struct cpumask *cpu_mask,
- struct cpumask *nmsk,
- struct irq_affinity_desc *masks)
-{
- unsigned int i, n, nodes, cpus_per_vec, extra_vecs, done = 0;
- unsigned int last_affv = firstvec + numvecs;
- unsigned int curvec = startvec;
- nodemask_t nodemsk = NODE_MASK_NONE;
- struct node_vectors *node_vectors;
-
- if (cpumask_empty(cpu_mask))
- return 0;
-
- nodes = get_nodes_in_cpumask(node_to_cpumask, cpu_mask, &nodemsk);
-
- /*
- * If the number of nodes in the mask is greater than or equal the
- * number of vectors we just spread the vectors across the nodes.
- */
- if (numvecs <= nodes) {
- for_each_node_mask(n, nodemsk) {
- /* Ensure that only CPUs which are in both masks are set */
- cpumask_and(nmsk, cpu_mask, node_to_cpumask[n]);
- cpumask_or(&masks[curvec].mask, &masks[curvec].mask, nmsk);
- if (++curvec == last_affv)
- curvec = firstvec;
- }
- return numvecs;
- }
-
- node_vectors = kcalloc(nr_node_ids,
- sizeof(struct node_vectors),
- GFP_KERNEL);
- if (!node_vectors)
- return -ENOMEM;
-
- /* allocate vector number for each node */
- alloc_nodes_vectors(numvecs, node_to_cpumask, cpu_mask,
- nodemsk, nmsk, node_vectors);
-
- for (i = 0; i < nr_node_ids; i++) {
- unsigned int ncpus, v;
- struct node_vectors *nv = &node_vectors[i];
-
- if (nv->nvectors == UINT_MAX)
- continue;
-
- /* Get the cpus on this node which are in the mask */
- cpumask_and(nmsk, cpu_mask, node_to_cpumask[nv->id]);
- ncpus = cpumask_weight(nmsk);
- if (!ncpus)
- continue;
-
- WARN_ON_ONCE(nv->nvectors > ncpus);
-
- /* Account for rounding errors */
- extra_vecs = ncpus - nv->nvectors * (ncpus / nv->nvectors);
-
- /* Spread allocated vectors on CPUs of the current node */
- for (v = 0; v < nv->nvectors; v++, curvec++) {
- cpus_per_vec = ncpus / nv->nvectors;
-
- /* Account for extra vectors to compensate rounding errors */
- if (extra_vecs) {
- cpus_per_vec++;
- --extra_vecs;
- }
-
- /*
- * wrapping has to be considered given 'startvec'
- * may start anywhere
- */
- if (curvec >= last_affv)
- curvec = firstvec;
- irq_spread_init_one(&masks[curvec].mask, nmsk,
- cpus_per_vec);
- }
- done += nv->nvectors;
- }
- kfree(node_vectors);
- return done;
-}
-
-/*
- * build affinity in two stages:
- * 1) spread present CPU on these vectors
- * 2) spread other possible CPUs on these vectors
- */
-static int irq_build_affinity_masks(unsigned int startvec, unsigned int numvecs,
- unsigned int firstvec,
- struct irq_affinity_desc *masks)
-{
- unsigned int curvec = startvec, nr_present = 0, nr_others = 0;
- cpumask_var_t *node_to_cpumask;
- cpumask_var_t nmsk, npresmsk;
- int ret = -ENOMEM;
-
- if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
- return ret;
-
- if (!zalloc_cpumask_var(&npresmsk, GFP_KERNEL))
- goto fail_nmsk;
-
- node_to_cpumask = alloc_node_to_cpumask();
- if (!node_to_cpumask)
- goto fail_npresmsk;
-
- /* Stabilize the cpumasks */
- cpus_read_lock();
- build_node_to_cpumask(node_to_cpumask);
-
- /* Spread on present CPUs starting from affd->pre_vectors */
- ret = __irq_build_affinity_masks(curvec, numvecs, firstvec,
- node_to_cpumask, cpu_present_mask,
- nmsk, masks);
- if (ret < 0)
- goto fail_build_affinity;
- nr_present = ret;
-
- /*
- * Spread on non present CPUs starting from the next vector to be
- * handled. If the spreading of present CPUs already exhausted the
- * vector space, assign the non present CPUs to the already spread
- * out vectors.
- */
- if (nr_present >= numvecs)
- curvec = firstvec;
- else
- curvec = firstvec + nr_present;
- cpumask_andnot(npresmsk, cpu_possible_mask, cpu_present_mask);
- ret = __irq_build_affinity_masks(curvec, numvecs, firstvec,
- node_to_cpumask, npresmsk, nmsk,
- masks);
- if (ret >= 0)
- nr_others = ret;
-
- fail_build_affinity:
- cpus_read_unlock();
-
- if (ret >= 0)
- WARN_ON(nr_present + nr_others < numvecs);
-
- free_node_to_cpumask(node_to_cpumask);
-
- fail_npresmsk:
- free_cpumask_var(npresmsk);
-
- fail_nmsk:
- free_cpumask_var(nmsk);
- return ret < 0 ? ret : 0;
-}
+#include <linux/group_cpus.h>
static void default_calc_sets(struct irq_affinity *affd, unsigned int affvecs)
{
*/
for (i = 0, usedvecs = 0; i < affd->nr_sets; i++) {
unsigned int this_vecs = affd->set_size[i];
- int ret;
+ int j;
+ struct cpumask *result = group_cpus_evenly(this_vecs);
- ret = irq_build_affinity_masks(curvec, this_vecs,
- curvec, masks);
- if (ret) {
+ if (!result) {
kfree(masks);
return NULL;
}
+
+ for (j = 0; j < this_vecs; j++)
+ cpumask_copy(&masks[curvec + j].mask, &result[j]);
+ kfree(result);
+
curvec += this_vecs;
usedvecs += this_vecs;
}
projects / linux-2.6-block.git / blobdiff