Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
"The irq department provides:
- two fixes for the CPU affinity spread infrastructure to prevent
unbalanced spreading in corner cases which leads to horrible
performance, because interrupts are rather aggregated than spread
- add a missing spinlock initializer in the imx-gpcv2 init code"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/irq-imx-gpcv2: Fix spinlock initialization
irq/affinity: Fix extra vecs calculation
irq/affinity: Fix CPU spread for unbalanced nodes
+13
-9
+2
drivers/irqchip/irq-imx-gpcv2.c
+2
drivers/irqchip/irq-imx-gpcv2.c
+11
-9
kernel/irq/affinity.c
+11
-9
kernel/irq/affinity.c
···
59
59
struct cpumask *
60
60
irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
61
61
{
62
-
int n, nodes, vecs_per_node, cpus_per_vec, extra_vecs, curvec;
62
+
int n, nodes, cpus_per_vec, extra_vecs, curvec;
63
63
int affv = nvecs - affd->pre_vectors - affd->post_vectors;
64
64
int last_affv = affv + affd->pre_vectors;
65
65
nodemask_t nodemsk = NODE_MASK_NONE;
···
94
94
goto done;
95
95
}
96
96
97
-
/* Spread the vectors per node */
98
-
vecs_per_node = affv / nodes;
99
-
/* Account for rounding errors */
100
-
extra_vecs = affv - (nodes * vecs_per_node);
101
-
102
97
for_each_node_mask(n, nodemsk) {
103
-
int ncpus, v, vecs_to_assign = vecs_per_node;
98
+
int ncpus, v, vecs_to_assign, vecs_per_node;
99
+
100
+
/* Spread the vectors per node */
101
+
vecs_per_node = (affv - curvec) / nodes;
104
102
105
103
/* Get the cpus on this node which are in the mask */
106
104
cpumask_and(nmsk, cpu_online_mask, cpumask_of_node(n));
107
105
108
106
/* Calculate the number of cpus per vector */
109
107
ncpus = cpumask_weight(nmsk);
108
+
vecs_to_assign = min(vecs_per_node, ncpus);
109
+
110
+
/* Account for rounding errors */
111
+
extra_vecs = ncpus - vecs_to_assign * (ncpus / vecs_to_assign);
110
112
111
113
for (v = 0; curvec < last_affv && v < vecs_to_assign;
112
114
curvec++, v++) {
···
117
115
/* Account for extra vectors to compensate rounding errors */
118
116
if (extra_vecs) {
119
117
cpus_per_vec++;
120
-
if (!--extra_vecs)
121
-
vecs_per_node++;
118
+
--extra_vecs;
122
119
}
123
120
irq_spread_init_one(masks + curvec, nmsk, cpus_per_vec);
124
121
}
125
122
126
123
if (curvec >= last_affv)
127
124
break;
125
+
--nodes;
128
126
}
129
127
130
128
done: