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authorDou Liyang <douly.fnst@cn.fujitsu.com>2018-09-09 01:58:37 +0800
committerThomas Gleixner <tglx@linutronix.de>2018-09-18 18:27:24 +0200
commit8ffe4e61c06a48324cfd97f1199bb9838acce2f2 (patch)
tree81572b0099e375518189f08c092b46f6f9da2d5f /kernel/irq/matrix.c
parent7876320f88802b22d4e2daf7eb027dd14175a0f8 (diff)
downloadlinux-stericsson-8ffe4e61c06a48324cfd97f1199bb9838acce2f2.tar.gz
irq/matrix: Split out the CPU selection code into a helper
Linux finds the CPU which has the lowest vector allocation count to spread out the non managed interrupts across the possible target CPUs, but does not do so for managed interrupts. Split out the CPU selection code into a helper function for reuse. No functional change. Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/20180908175838.14450-1-dou_liyang@163.com
Diffstat (limited to 'kernel/irq/matrix.c')
-rw-r--r--kernel/irq/matrix.c65
1 files changed, 38 insertions, 27 deletions
diff --git a/kernel/irq/matrix.c b/kernel/irq/matrix.c
index 5092494bf261..67768bbe736e 100644
--- a/kernel/irq/matrix.c
+++ b/kernel/irq/matrix.c
@@ -124,6 +124,27 @@ static unsigned int matrix_alloc_area(struct irq_matrix *m, struct cpumap *cm,
return area;
}
+/* Find the best CPU which has the lowest vector allocation count */
+static unsigned int matrix_find_best_cpu(struct irq_matrix *m,
+ const struct cpumask *msk)
+{
+ unsigned int cpu, best_cpu, maxavl = 0;
+ struct cpumap *cm;
+
+ best_cpu = UINT_MAX;
+
+ for_each_cpu(cpu, msk) {
+ cm = per_cpu_ptr(m->maps, cpu);
+
+ if (!cm->online || cm->available <= maxavl)
+ continue;
+
+ best_cpu = cpu;
+ maxavl = cm->available;
+ }
+ return best_cpu;
+}
+
/**
* irq_matrix_assign_system - Assign system wide entry in the matrix
* @m: Matrix pointer
@@ -322,37 +343,27 @@ void irq_matrix_remove_reserved(struct irq_matrix *m)
int irq_matrix_alloc(struct irq_matrix *m, const struct cpumask *msk,
bool reserved, unsigned int *mapped_cpu)
{
- unsigned int cpu, best_cpu, maxavl = 0;
+ unsigned int cpu, bit;
struct cpumap *cm;
- unsigned int bit;
- best_cpu = UINT_MAX;
- for_each_cpu(cpu, msk) {
- cm = per_cpu_ptr(m->maps, cpu);
-
- if (!cm->online || cm->available <= maxavl)
- continue;
+ cpu = matrix_find_best_cpu(m, msk);
+ if (cpu == UINT_MAX)
+ return -ENOSPC;
- best_cpu = cpu;
- maxavl = cm->available;
- }
+ cm = per_cpu_ptr(m->maps, cpu);
+ bit = matrix_alloc_area(m, cm, 1, false);
+ if (bit >= m->alloc_end)
+ return -ENOSPC;
+ cm->allocated++;
+ cm->available--;
+ m->total_allocated++;
+ m->global_available--;
+ if (reserved)
+ m->global_reserved--;
+ *mapped_cpu = cpu;
+ trace_irq_matrix_alloc(bit, cpu, m, cm);
+ return bit;
- if (maxavl) {
- cm = per_cpu_ptr(m->maps, best_cpu);
- bit = matrix_alloc_area(m, cm, 1, false);
- if (bit < m->alloc_end) {
- cm->allocated++;
- cm->available--;
- m->total_allocated++;
- m->global_available--;
- if (reserved)
- m->global_reserved--;
- *mapped_cpu = best_cpu;
- trace_irq_matrix_alloc(bit, best_cpu, m, cm);
- return bit;
- }
- }
- return -ENOSPC;
}
/**