From 4595f9620cda8a1e973588e743cf5f8436dd20c6 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Sat, 10 Jan 2009 21:58:09 -0800 Subject: x86: change flush_tlb_others to take a const struct cpumask Impact: reduce stack usage, use new cpumask API. This is made a little more tricky by uv_flush_tlb_others which actually alters its argument, for an IPI to be sent to the remaining cpus in the mask. I solve this by allocating a cpumask_var_t for this case and falling back to IPI should this fail. To eliminate temporaries in the caller, all flush_tlb_others implementations now do the this-cpu-elimination step themselves. Note also the curious "cpus_or(f->flush_cpumask, cpumask, f->flush_cpumask)" which has been there since pre-git and yet f->flush_cpumask is always zero at this point. Signed-off-by: Rusty Russell Signed-off-by: Mike Travis --- arch/x86/kernel/tlb_32.c | 67 +++++++++++++++++++++--------------------------- 1 file changed, 29 insertions(+), 38 deletions(-) (limited to 'arch/x86/kernel/tlb_32.c') diff --git a/arch/x86/kernel/tlb_32.c b/arch/x86/kernel/tlb_32.c index ce505464224..ec53818f4e3 100644 --- a/arch/x86/kernel/tlb_32.c +++ b/arch/x86/kernel/tlb_32.c @@ -20,7 +20,7 @@ DEFINE_PER_CPU(struct tlb_state, cpu_tlbstate) * Optimizations Manfred Spraul */ -static cpumask_t flush_cpumask; +static cpumask_var_t flush_cpumask; static struct mm_struct *flush_mm; static unsigned long flush_va; static DEFINE_SPINLOCK(tlbstate_lock); @@ -92,7 +92,7 @@ void smp_invalidate_interrupt(struct pt_regs *regs) cpu = get_cpu(); - if (!cpu_isset(cpu, flush_cpumask)) + if (!cpumask_test_cpu(cpu, flush_cpumask)) goto out; /* * This was a BUG() but until someone can quote me the @@ -114,35 +114,22 @@ void smp_invalidate_interrupt(struct pt_regs *regs) } ack_APIC_irq(); smp_mb__before_clear_bit(); - cpu_clear(cpu, flush_cpumask); + cpumask_clear_cpu(cpu, flush_cpumask); smp_mb__after_clear_bit(); out: put_cpu_no_resched(); inc_irq_stat(irq_tlb_count); } -void native_flush_tlb_others(const cpumask_t *cpumaskp, struct mm_struct *mm, - unsigned long va) +void native_flush_tlb_others(const struct cpumask *cpumask, + struct mm_struct *mm, unsigned long va) { - cpumask_t cpumask = *cpumaskp; - /* - * A couple of (to be removed) sanity checks: - * - * - current CPU must not be in mask * - mask must exist :) */ - BUG_ON(cpus_empty(cpumask)); - BUG_ON(cpu_isset(smp_processor_id(), cpumask)); + BUG_ON(cpumask_empty(cpumask)); BUG_ON(!mm); -#ifdef CONFIG_HOTPLUG_CPU - /* If a CPU which we ran on has gone down, OK. */ - cpus_and(cpumask, cpumask, cpu_online_map); - if (unlikely(cpus_empty(cpumask))) - return; -#endif - /* * i'm not happy about this global shared spinlock in the * MM hot path, but we'll see how contended it is. @@ -150,9 +137,17 @@ void native_flush_tlb_others(const cpumask_t *cpumaskp, struct mm_struct *mm, */ spin_lock(&tlbstate_lock); + cpumask_andnot(flush_cpumask, cpumask, cpumask_of(smp_processor_id())); +#ifdef CONFIG_HOTPLUG_CPU + /* If a CPU which we ran on has gone down, OK. */ + cpumask_and(flush_cpumask, flush_cpumask, cpu_online_mask); + if (unlikely(cpumask_empty(flush_cpumask))) { + spin_unlock(&tlbstate_lock); + return; + } +#endif flush_mm = mm; flush_va = va; - cpus_or(flush_cpumask, cpumask, flush_cpumask); /* * Make the above memory operations globally visible before @@ -163,9 +158,9 @@ void native_flush_tlb_others(const cpumask_t *cpumaskp, struct mm_struct *mm, * We have to send the IPI only to * CPUs affected. */ - send_IPI_mask(&cpumask, INVALIDATE_TLB_VECTOR); + send_IPI_mask(flush_cpumask, INVALIDATE_TLB_VECTOR); - while (!cpus_empty(flush_cpumask)) + while (!cpumask_empty(flush_cpumask)) /* nothing. lockup detection does not belong here */ cpu_relax(); @@ -177,25 +172,19 @@ void native_flush_tlb_others(const cpumask_t *cpumaskp, struct mm_struct *mm, void flush_tlb_current_task(void) { struct mm_struct *mm = current->mm; - cpumask_t cpu_mask; preempt_disable(); - cpu_mask = mm->cpu_vm_mask; - cpu_clear(smp_processor_id(), cpu_mask); local_flush_tlb(); - if (!cpus_empty(cpu_mask)) - flush_tlb_others(cpu_mask, mm, TLB_FLUSH_ALL); + if (cpumask_any_but(&mm->cpu_vm_mask, smp_processor_id()) < nr_cpu_ids) + flush_tlb_others(&mm->cpu_vm_mask, mm, TLB_FLUSH_ALL); preempt_enable(); } void flush_tlb_mm(struct mm_struct *mm) { - cpumask_t cpu_mask; preempt_disable(); - cpu_mask = mm->cpu_vm_mask; - cpu_clear(smp_processor_id(), cpu_mask); if (current->active_mm == mm) { if (current->mm) @@ -203,8 +192,8 @@ void flush_tlb_mm(struct mm_struct *mm) else leave_mm(smp_processor_id()); } - if (!cpus_empty(cpu_mask)) - flush_tlb_others(cpu_mask, mm, TLB_FLUSH_ALL); + if (cpumask_any_but(&mm->cpu_vm_mask, smp_processor_id()) < nr_cpu_ids) + flush_tlb_others(&mm->cpu_vm_mask, mm, TLB_FLUSH_ALL); preempt_enable(); } @@ -212,11 +201,8 @@ void flush_tlb_mm(struct mm_struct *mm) void flush_tlb_page(struct vm_area_struct *vma, unsigned long va) { struct mm_struct *mm = vma->vm_mm; - cpumask_t cpu_mask; preempt_disable(); - cpu_mask = mm->cpu_vm_mask; - cpu_clear(smp_processor_id(), cpu_mask); if (current->active_mm == mm) { if (current->mm) @@ -225,9 +211,8 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long va) leave_mm(smp_processor_id()); } - if (!cpus_empty(cpu_mask)) - flush_tlb_others(cpu_mask, mm, va); - + if (cpumask_any_but(&mm->cpu_vm_mask, smp_processor_id()) < nr_cpu_ids) + flush_tlb_others(&mm->cpu_vm_mask, mm, va); preempt_enable(); } EXPORT_SYMBOL(flush_tlb_page); @@ -254,3 +239,9 @@ void reset_lazy_tlbstate(void) per_cpu(cpu_tlbstate, cpu).active_mm = &init_mm; } +static int init_flush_cpumask(void) +{ + alloc_cpumask_var(&flush_cpumask, GFP_KERNEL); + return 0; +} +early_initcall(init_flush_cpumask); -- cgit v1.2.3