Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (66f81624) · Commits · 戴 / test

Pull irq fix from Thomas Gleixner: "A single fix for the new matrix allocator to prevent vector exhaustion by certain network drivers which allocate gazillions of unused vectors which cannot be put into reservation mode due to MSI and the lack of MSI entry masking. The fix/workaround is to spread the vectors across CPUs by searching the supplied target CPU mask for the CPU with the smallest number of allocated vectors" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irq/matrix: Spread interrupts on allocation

kernel/irq/matrix.c

+14 −6

Original line number	Diff line number	Diff line
		@@ -321,15 +321,23 @@ 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;
		unsigned int cpu, best_cpu, maxavl = 0;
		struct cpumap *cm;
		unsigned int bit;

		best_cpu = UINT_MAX;
		for_each_cpu(cpu, msk) {
		struct cpumap *cm = per_cpu_ptr(m->maps, cpu);
		unsigned int bit;
		cm = per_cpu_ptr(m->maps, cpu);

		if (!cm->online)
		if (!cm->online \|\| cm->available <= maxavl)
		continue;

		best_cpu = cpu;
		maxavl = cm->available;
		}

		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++;
		@@ -338,8 +346,8 @@ int irq_matrix_alloc(struct irq_matrix m, const struct cpumask msk,
		m->global_available--;
		if (reserved)
		m->global_reserved--;
		*mapped_cpu = cpu;
		trace_irq_matrix_alloc(bit, cpu, m, cm);
		*mapped_cpu = best_cpu;
		trace_irq_matrix_alloc(bit, best_cpu, m, cm);
		return bit;
		}
		}

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