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genirq/affinity: Allow irq spreading from a given starting point

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To support two stage irq vector spreading, it's required to add a starting
point to the spreading function. No functional change, just preparatory
work for the actual two stage change.

[ tglx: Renamed variables, tidied up the code and massaged changelog ]

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Link: https://lkml.kernel.org/r/20180308105358.1506-4-ming.lei@redhat.com
This commit is contained in:
Ming Lei 2018-03-08 18:53:57 +08:00 committed by Thomas Gleixner
parent b3e6aaa8d9
commit 1a2d0914e2
1 changed files with 20 additions and 15 deletions
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35
kernel/irq/affinity.c
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@ -94,17 +94,17 @@ static int get_nodes_in_cpumask(cpumask_var_t *node_to_cpumask,
return nodes;
}
static int irq_build_affinity_masks(int nvecs, const struct irq_affinity *affd,
static int irq_build_affinity_masks(const struct irq_affinity *affd,
int startvec, int numvecs,
cpumask_var_t *node_to_cpumask,
const struct cpumask *cpu_mask,
struct cpumask *nmsk,
struct cpumask *masks)
{
int affv = nvecs - affd->pre_vectors - affd->post_vectors;
int last_affv = affv + affd->pre_vectors;
int curvec = affd->pre_vectors;
int n, nodes, cpus_per_vec, extra_vecs, done = 0;
int last_affv = affd->pre_vectors + numvecs;
int curvec = startvec;
nodemask_t nodemsk = NODE_MASK_NONE;
int n, nodes, cpus_per_vec, extra_vecs;
nodes = get_nodes_in_cpumask(node_to_cpumask, cpu_mask, &nodemsk);
@ -112,12 +112,13 @@ static int irq_build_affinity_masks(int nvecs, const struct irq_affinity *affd,
* 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 (affv <= nodes) {
if (numvecs <= nodes) {
for_each_node_mask(n, nodemsk) {
cpumask_copy(masks + curvec,
node_to_cpumask[n]);
if (++curvec == last_affv)
cpumask_copy(masks + curvec, node_to_cpumask[n]);
if (++done == numvecs)
break;
if (++curvec == last_affv)
curvec = affd->pre_vectors;
}
goto out;
}
@ -126,7 +127,7 @@ static int irq_build_affinity_masks(int nvecs, const struct irq_affinity *affd,
int ncpus, v, vecs_to_assign, vecs_per_node;
/* Spread the vectors per node */
vecs_per_node = (affv - (curvec - affd->pre_vectors)) / nodes;
vecs_per_node = (numvecs - (curvec - affd->pre_vectors)) / nodes;
/* Get the cpus on this node which are in the mask */
cpumask_and(nmsk, cpu_mask, node_to_cpumask[n]);
@ -150,13 +151,16 @@ static int irq_build_affinity_masks(int nvecs, const struct irq_affinity *affd,
irq_spread_init_one(masks + curvec, nmsk, cpus_per_vec);
}
if (curvec >= last_affv)
done += v;
if (done >= numvecs)
break;
if (curvec >= last_affv)
curvec = affd->pre_vectors;
--nodes;
}
out:
return curvec - affd->pre_vectors;
return done;
}
/**
@ -169,9 +173,9 @@ out:
struct cpumask *
irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
{
int curvec, affvecs = nvecs - affd->pre_vectors - affd->post_vectors;
cpumask_var_t nmsk, *node_to_cpumask;
struct cpumask *masks = NULL;
int curvec;
/*
* If there aren't any vectors left after applying the pre/post
@ -198,8 +202,9 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
/* Stabilize the cpumasks */
get_online_cpus();
build_node_to_cpumask(node_to_cpumask);
curvec += irq_build_affinity_masks(nvecs, affd, node_to_cpumask,
cpu_possible_mask, nmsk, masks);
curvec += irq_build_affinity_masks(affd, curvec, affvecs,
node_to_cpumask, cpu_possible_mask,
nmsk, masks);
put_online_cpus();
/* Fill out vectors at the end that don't need affinity */