genirq/affinity: Rename irq_build_affinity_masks as group_cpus_evenly

#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)

static void grp_spread_init_one(struct cpumask *irqmsk, struct cpumask *nmsk,

				unsigned int cpus_per_grp)

{

	const struct cpumask *siblmsk;

	int cpu, sibl;

	for ( ; cpus_per_vec > 0; ) {

	for ( ; cpus_per_grp > 0; ) {

		cpu = cpumask_first(nmsk);

		/* Should not happen, but I'm too lazy to think about it */

		cpumask_clear_cpu(cpu, nmsk);

		cpumask_set_cpu(cpu, irqmsk);

		cpus_per_vec--;

		cpus_per_grp--;

		/* If the cpu has siblings, use them first */

		siblmsk = topology_sibling_cpumask(cpu);

		for (sibl = -1; cpus_per_vec > 0; ) {

		for (sibl = -1; cpus_per_grp > 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--;

			cpus_per_grp--;

		}

	}

}

	return nodes;

}

struct node_vectors {

struct node_groups {

	unsigned id;

	union {

		unsigned nvectors;

		unsigned ngroups;

		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;

	const struct node_groups *ln = l;

	const struct node_groups *rn = r;

	return ln->ncpus - rn->ncpus;

}

/*

 * Allocate vector number for each node, so that for each node:

 * Allocate group 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

 * 2) the allocated number 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.

 * The actual allocated total groups may be less than @numgrps when

 * active total CPU number is less than @numgrps.

 *

 * Active CPUs means the CPUs in '@cpu_mask AND @node_to_cpumask[]'

 * for each node.

 */

static void alloc_nodes_vectors(unsigned int numvecs,

static void alloc_nodes_groups(unsigned int numgrps,

			       cpumask_var_t *node_to_cpumask,

			       const struct cpumask *cpu_mask,

			       const nodemask_t nodemsk,

			       struct cpumask *nmsk,

				struct node_vectors *node_vectors)

			       struct node_groups *node_groups)

{

	unsigned n, remaining_ncpus = 0;

	for (n = 0; n < nr_node_ids; n++) {

		node_vectors[n].id = n;

		node_vectors[n].ncpus = UINT_MAX;

		node_groups[n].id = n;

		node_groups[n].ncpus = UINT_MAX;

	}

	for_each_node_mask(n, nodemsk) {

		if (!ncpus)

			continue;

		remaining_ncpus += ncpus;

		node_vectors[n].ncpus = ncpus;

		node_groups[n].ncpus = ncpus;

	}

	numvecs = min_t(unsigned, remaining_ncpus, numvecs);

	numgrps = min_t(unsigned, remaining_ncpus, numgrps);

	sort(node_vectors, nr_node_ids, sizeof(node_vectors[0]),

	sort(node_groups, nr_node_ids, sizeof(node_groups[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

	 * Allocate groups for each node according to the ratio of this

	 * node's nr_cpus to remaining un-assigned ncpus. 'numgrps' 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

	 * least one group, and the theory is simple: over-allocation

	 * is only done when this node is assigned by one group, so

	 * other nodes will be allocated >= 1 groups, since 'numgrps' is

	 * bigger than number of numa nodes.

	 *

	 * One perfect invariant is that number of allocated vectors for

	 * One perfect invariant is that number of allocated groups 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

	 * 	grps(X) is the group count allocated to node X via this

	 * 	algorithm

	 *

	 * 	ncpu(A) <= ncpu(B)

	 * 	ncpu(A) + ncpu(B) = N

	 * 	vecs(A) + vecs(B) = V

	 * 	grps(A) + grps(B) = G

	 *

	 * 	vecs(A) = max(1, round_down(V * ncpu(A) / N))

	 * 	vecs(B) = V - vecs(A)

	 * 	grps(A) = max(1, round_down(G * ncpu(A) / N))

	 * 	grps(B) = G - grps(A)

	 *

	 * 	both N and V are integer, and 2 <= V <= N, suppose

	 * 	V = N - delta, and 0 <= delta <= N - 2

	 * 	both N and G are integer, and 2 <= G <= N, suppose

	 * 	G = N - delta, and 0 <= delta <= N - 2

	 *

	 * 2) obviously vecs(A) <= ncpu(A) because:

	 * 2) obviously grps(A) <= ncpu(A) because:

	 *

	 * 	if vecs(A) is 1, then vecs(A) <= ncpu(A) given

	 * 	if grps(A) is 1, then grps(A) <= ncpu(A) given

	 * 	ncpu(A) >= 1

	 *

	 * 	otherwise,

	 * 		vecs(A) <= V * ncpu(A) / N <= ncpu(A), given V <= N

	 * 		grps(A) <= G * ncpu(A) / N <= ncpu(A), given G <= N

	 *

	 * 3) prove how vecs(B) <= ncpu(B):

	 * 3) prove how grps(B) <= ncpu(B):

	 *

	 * 	if round_down(V * ncpu(A) / N) == 0, vecs(B) won't be

	 * 	over-allocated, so vecs(B) <= ncpu(B),

	 * 	if round_down(G * ncpu(A) / N) == 0, vecs(B) won't be

	 * 	over-allocated, so grps(B) <= ncpu(B),

	 *

	 * 	otherwise:

	 *

	 * 	vecs(A) =

	 * 		round_down(V * ncpu(A) / N) =

	 * 	grps(A) =

	 * 		round_down(G * 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)	 =

	 *

	 * 	then:

	 *

	 * 	vecs(A) - V >= ncpu(A) - delta - V

	 * 	grps(A) - G >= ncpu(A) - delta - G

	 * 	=>

	 * 	V - vecs(A) <= V + delta - ncpu(A)

	 * 	G - grps(A) <= G + delta - ncpu(A)

	 * 	=>

	 * 	vecs(B) <= N - ncpu(A)

	 * 	grps(B) <= N - ncpu(A)

	 * 	=>

	 * 	vecs(B) <= cpu(B)

	 * 	grps(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).

	 * and we always re-calculate 'remaining_ncpus' & 'numgrps', and

	 * finally for each node X: grps(X) <= ncpu(X).

	 *

	 */

	for (n = 0; n < nr_node_ids; n++) {

		unsigned nvectors, ncpus;

		unsigned ngroups, ncpus;

		if (node_vectors[n].ncpus == UINT_MAX)

		if (node_groups[n].ncpus == UINT_MAX)

			continue;

		WARN_ON_ONCE(numvecs == 0);

		WARN_ON_ONCE(numgrps == 0);

		ncpus = node_vectors[n].ncpus;

		nvectors = max_t(unsigned, 1,

				 numvecs * ncpus / remaining_ncpus);

		WARN_ON_ONCE(nvectors > ncpus);

		ncpus = node_groups[n].ncpus;

		ngroups = max_t(unsigned, 1,

				 numgrps * ncpus / remaining_ncpus);

		WARN_ON_ONCE(ngroups > ncpus);

		node_vectors[n].nvectors = nvectors;

		node_groups[n].ngroups = ngroups;

		remaining_ncpus -= ncpus;

		numvecs -= nvectors;

		numgrps -= ngroups;

	}

}

static int __irq_build_affinity_masks(unsigned int startvec,

				      unsigned int numvecs,

static int __group_cpus_evenly(unsigned int startgrp, unsigned int numgrps,

			       cpumask_var_t *node_to_cpumask,

			       const struct cpumask *cpu_mask,

				      struct cpumask *nmsk,

				      struct cpumask *masks)

			       struct cpumask *nmsk, struct cpumask *masks)

{

	unsigned int i, n, nodes, cpus_per_vec, extra_vecs, done = 0;

	unsigned int last_affv = numvecs;

	unsigned int curvec = startvec;

	unsigned int i, n, nodes, cpus_per_grp, extra_grps, done = 0;

	unsigned int last_grp = numgrps;

	unsigned int curgrp = startgrp;

	nodemask_t nodemsk = NODE_MASK_NONE;

	struct node_vectors *node_vectors;

	struct node_groups *node_groups;

	if (cpumask_empty(cpu_mask))

		return 0;

	/*

	 * 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.

	 * number of groups we just spread the groups across the nodes.

	 */

	if (numvecs <= nodes) {

	if (numgrps <= 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], &masks[curvec], nmsk);

			if (++curvec == last_affv)

				curvec = 0;

			cpumask_or(&masks[curgrp], &masks[curgrp], nmsk);

			if (++curgrp == last_grp)

				curgrp = 0;

		}

		return numvecs;

		return numgrps;

	}

	node_vectors = kcalloc(nr_node_ids,

			       sizeof(struct node_vectors),

	node_groups = kcalloc(nr_node_ids,

			       sizeof(struct node_groups),

			       GFP_KERNEL);

	if (!node_vectors)

	if (!node_groups)

		return -ENOMEM;

	/* allocate vector number for each node */

	alloc_nodes_vectors(numvecs, node_to_cpumask, cpu_mask,

			    nodemsk, nmsk, node_vectors);

	/* allocate group number for each node */

	alloc_nodes_groups(numgrps, node_to_cpumask, cpu_mask,

			   nodemsk, nmsk, node_groups);

	for (i = 0; i < nr_node_ids; i++) {

		unsigned int ncpus, v;

		struct node_vectors *nv = &node_vectors[i];

		struct node_groups *nv = &node_groups[i];

		if (nv->nvectors == UINT_MAX)

		if (nv->ngroups == UINT_MAX)

			continue;

		/* Get the cpus on this node which are in the mask */

		if (!ncpus)

			continue;

		WARN_ON_ONCE(nv->nvectors > ncpus);

		WARN_ON_ONCE(nv->ngroups > ncpus);

		/* Account for rounding errors */

		extra_vecs = ncpus - nv->nvectors * (ncpus / nv->nvectors);

		extra_grps = ncpus - nv->ngroups * (ncpus / nv->ngroups);

		/* Spread allocated vectors on CPUs of the current node */

		for (v = 0; v < nv->nvectors; v++, curvec++) {

			cpus_per_vec = ncpus / nv->nvectors;

		/* Spread allocated groups on CPUs of the current node */

		for (v = 0; v < nv->ngroups; v++, curgrp++) {

			cpus_per_grp = ncpus / nv->ngroups;

			/* Account for extra vectors to compensate rounding errors */

			if (extra_vecs) {

				cpus_per_vec++;

				--extra_vecs;

			/* Account for extra groups to compensate rounding errors */

			if (extra_grps) {

				cpus_per_grp++;

				--extra_grps;

			}

			/*

			 * wrapping has to be considered given 'startvec'

			 * wrapping has to be considered given 'startgrp'

			 * may start anywhere

			 */

			if (curvec >= last_affv)

				curvec = 0;

			irq_spread_init_one(&masks[curvec], nmsk,

						cpus_per_vec);

			if (curgrp >= last_grp)

				curgrp = 0;

			grp_spread_init_one(&masks[curgrp], nmsk,

						cpus_per_grp);

		}

		done += nv->nvectors;

		done += nv->ngroups;

	}

	kfree(node_vectors);

	kfree(node_groups);

	return done;

}

/*

 * build affinity in two stages:

 *	1) spread present CPU on these vectors

 *	2) spread other possible CPUs on these vectors

 * build affinity in two stages for each group, and try to put close CPUs

 * in viewpoint of CPU and NUMA locality into same group, and we run

 * two-stage grouping:

 *

 *	1) allocate present CPUs on these groups evenly first

 *	2) allocate other possible CPUs on these groups evenly

 */

static struct cpumask *irq_build_affinity_masks(unsigned int numvecs)

static struct cpumask *group_cpus_evenly(unsigned int numgrps)

{

	unsigned int curvec = 0, nr_present = 0, nr_others = 0;

	unsigned int curgrp = 0, nr_present = 0, nr_others = 0;

	cpumask_var_t *node_to_cpumask;

	cpumask_var_t nmsk, npresmsk;

	int ret = -ENOMEM;

	if (!node_to_cpumask)

		goto fail_npresmsk;

	masks = kcalloc(numvecs, sizeof(*masks), GFP_KERNEL);

	masks = kcalloc(numgrps, sizeof(*masks), GFP_KERNEL);

	if (!masks)

		goto fail_node_to_cpumask;

	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, node_to_cpumask,

	/* grouping present CPUs first */

	ret = __group_cpus_evenly(curgrp, numgrps, 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.

	 * Allocate non present CPUs starting from the next group to be

	 * handled. If the grouping of present CPUs already exhausted the

	 * group space, assign the non present CPUs to the already

	 * allocated out groups.

	 */

	if (nr_present >= numvecs)

		curvec = 0;

	if (nr_present >= numgrps)

		curgrp = 0;

	else

		curvec = nr_present;

		curgrp = nr_present;

	cpumask_andnot(npresmsk, cpu_possible_mask, cpu_present_mask);

	ret = __irq_build_affinity_masks(curvec, numvecs, node_to_cpumask,

	ret = __group_cpus_evenly(curgrp, numgrps, node_to_cpumask,

				  npresmsk, nmsk, masks);

	if (ret >= 0)

		nr_others = ret;

	cpus_read_unlock();

	if (ret >= 0)

		WARN_ON(nr_present + nr_others < numvecs);

		WARN_ON(nr_present + nr_others < numgrps);

 fail_node_to_cpumask:

	free_node_to_cpumask(node_to_cpumask);

	for (i = 0, usedvecs = 0; i < affd->nr_sets; i++) {

		unsigned int this_vecs = affd->set_size[i];

		int j;

		struct cpumask *result = irq_build_affinity_masks(this_vecs);

		struct cpumask *result = group_cpus_evenly(this_vecs);

		if (!result) {

			kfree(masks);