SGI UV cpumask: use static temp cpumask in flush_tlb (0e21990a) · Commits · 戴 / test

Impact: Improve tlb flush performance for UV Calling alloc_cpumask_var a zillion times a second does affect performance. Replace with static cpumask. Note: when CONFIG_X86_UV is defined, this extra PER_CPU memory will be optimized out for non-UV configs as is_uv_system() will then return a constant 0. Signed-off-by:

Mike Travis <travis@sgi.com>

arch/x86/kernel/tlb_64.c

+11 −10

Original line number	Diff line number	Diff line
		@@ -202,17 +202,18 @@ void native_flush_tlb_others(const struct cpumask *cpumask,
		struct mm_struct *mm, unsigned long va)
		{
		if (is_uv_system()) {
		cpumask_var_t after_uv_flush;
		/* FIXME: could be an percpu_alloc'd thing */
		static DEFINE_PER_CPU(cpumask_t, flush_tlb_mask);
		struct cpumask *after_uv_flush = &get_cpu_var(flush_tlb_mask);

		if (alloc_cpumask_var(&after_uv_flush, GFP_ATOMIC)) {
		cpumask_andnot(after_uv_flush,
		cpumask, cpumask_of(smp_processor_id()));
		cpumask_andnot(after_uv_flush, cpumask,
		cpumask_of(smp_processor_id()));
		if (!uv_flush_tlb_others(after_uv_flush, mm, va))
		flush_tlb_others_ipi(after_uv_flush, mm, va);
		free_cpumask_var(after_uv_flush);

		put_cpu_var(flush_tlb_uv_cpumask);
		return;
		}
		}
		flush_tlb_others_ipi(cpumask, mm, va);
		}

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