genirq/affinity: Move two stage affinity spreading into a helper function

No functional change. Prepares for supporting allocating and affinitizing
interrupt sets.

[ tglx: Minor changelog tweaks ]

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: Hannes Reinecke <hare@suse.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Link: https://lkml.kernel.org/r/20181102145951.31979-3-ming.lei@redhat.com

diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index e12cdf637c71bafaa515564fe83bdd3170ddd3e1..2f9812b6035e188f0b6209375c16c50832225acd 100644 (file)
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -94,7 +94,7 @@ static int get_nodes_in_cpumask(cpumask_var_t *node_to_cpumask,
        return nodes;
 }
 
-static int irq_build_affinity_masks(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,
@@ -165,6 +165,58 @@ out:
        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(const struct irq_affinity *affd,
+                                   int startvec, int numvecs,
+                                   cpumask_var_t *node_to_cpumask,
+                                   struct cpumask *masks)
+{
+       int curvec = startvec, usedvecs = -1;
+       cpumask_var_t nmsk, npresmsk;
+
+       if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
+                       return usedvecs;
+
+       if (!zalloc_cpumask_var(&npresmsk, GFP_KERNEL))
+                       goto fail;
+
+       /* Stabilize the cpumasks */
+       get_online_cpus();
+       build_node_to_cpumask(node_to_cpumask);
+
+       /* Spread on present CPUs starting from affd->pre_vectors */
+       usedvecs = __irq_build_affinity_masks(affd, curvec, numvecs,
+                                           node_to_cpumask, cpu_present_mask,
+                                           nmsk, masks);
+
+       /*
+        * 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 (usedvecs >= numvecs)
+               curvec = affd->pre_vectors;
+       else
+               curvec = affd->pre_vectors + usedvecs;
+       cpumask_andnot(npresmsk, cpu_possible_mask, cpu_present_mask);
+       usedvecs += __irq_build_affinity_masks(affd, curvec, numvecs,
+                                            node_to_cpumask, npresmsk,
+                                            nmsk, masks);
+       put_online_cpus();
+
+       free_cpumask_var(npresmsk);
+
+ fail:
+       free_cpumask_var(nmsk);
+
+       return usedvecs;
+}
+
 /**
  * irq_create_affinity_masks - Create affinity masks for multiqueue spreading
  * @nvecs:     The total number of vectors
@@ -177,7 +229,7 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
 {
        int affvecs = nvecs - affd->pre_vectors - affd->post_vectors;
        int curvec, usedvecs;
-       cpumask_var_t nmsk, npresmsk, *node_to_cpumask;
+       cpumask_var_t *node_to_cpumask;
        struct cpumask *masks = NULL;
 
        /*
@@ -187,15 +239,9 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
        if (nvecs == affd->pre_vectors + affd->post_vectors)
                return NULL;
 
-       if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
-               return NULL;
-
-       if (!zalloc_cpumask_var(&npresmsk, GFP_KERNEL))
-               goto outcpumsk;
-
        node_to_cpumask = alloc_node_to_cpumask();
        if (!node_to_cpumask)
-               goto outnpresmsk;
+               return NULL;
 
        masks = kcalloc(nvecs, sizeof(*masks), GFP_KERNEL);
        if (!masks)
@@ -205,30 +251,8 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
        for (curvec = 0; curvec < affd->pre_vectors; curvec++)
                cpumask_copy(masks + curvec, irq_default_affinity);
 
-       /* Stabilize the cpumasks */
-       get_online_cpus();
-       build_node_to_cpumask(node_to_cpumask);
-
-       /* Spread on present CPUs starting from affd->pre_vectors */
        usedvecs = irq_build_affinity_masks(affd, curvec, affvecs,
-                                           node_to_cpumask, cpu_present_mask,
-                                           nmsk, masks);
-
-       /*
-        * 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 (usedvecs >= affvecs)
-               curvec = affd->pre_vectors;
-       else
-               curvec = affd->pre_vectors + usedvecs;
-       cpumask_andnot(npresmsk, cpu_possible_mask, cpu_present_mask);
-       usedvecs += irq_build_affinity_masks(affd, curvec, affvecs,
-                                            node_to_cpumask, npresmsk,
-                                            nmsk, masks);
-       put_online_cpus();
+                                           node_to_cpumask, masks);
 
        /* Fill out vectors at the end that don't need affinity */
        if (usedvecs >= affvecs)
@@ -240,10 +264,6 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
 
 outnodemsk:
        free_node_to_cpumask(node_to_cpumask);
-outnpresmsk:
-       free_cpumask_var(npresmsk);
-outcpumsk:
-       free_cpumask_var(nmsk);
        return masks;
 }