From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f69.google.com (mail-oi0-f69.google.com [209.85.218.69]) by kanga.kvack.org (Postfix) with ESMTP id BE1876B02B4 for ; Mon, 22 May 2017 18:30:19 -0400 (EDT) Received: by mail-oi0-f69.google.com with SMTP id c71so175461956oig.1 for ; Mon, 22 May 2017 15:30:19 -0700 (PDT) Received: from mail.kernel.org (mail.kernel.org. [198.145.29.99]) by mx.google.com with ESMTPS id t51si52016otb.245.2017.05.22.15.30.18 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 22 May 2017 15:30:19 -0700 (PDT) From: Andy Lutomirski Subject: [PATCH v2 01/11] x86/mm: Reimplement flush_tlb_page() using flush_tlb_mm_range() Date: Mon, 22 May 2017 15:30:01 -0700 Message-Id: <3cc3847cf888d8907577569b8bac3f01992ef8f9.1495492063.git.luto@kernel.org> In-Reply-To: References: In-Reply-To: References: Sender: owner-linux-mm@kvack.org List-ID: To: X86 ML Cc: "linux-kernel@vger.kernel.org" , Borislav Petkov , Linus Torvalds , Andrew Morton , Mel Gorman , "linux-mm@kvack.org" , Nadav Amit , Andy Lutomirski , Rik van Riel , Dave Hansen , Nadav Amit , Michal Hocko flush_tlb_page() was very similar to flush_tlb_mm_range() except that it had a couple of issues: - It was missing an smp_mb() in the case where current->active_mm != mm. (This is a longstanding bug reported by Nadav Amit.) - It was missing tracepoints and vm counter updates. The only reason that I can see for keeping it at as a separate function is that it could avoid a few branches that flush_tlb_mm_range() needs to decide to flush just one page. This hardly seems worthwhile. If we decide we want to get rid of those branches again, a better way would be to introduce an __flush_tlb_mm_range() helper and make both flush_tlb_page() and flush_tlb_mm_range() use it. Cc: Rik van Riel Cc: Dave Hansen Cc: Nadav Amit Cc: Michal Hocko Cc: Andrew Morton Signed-off-by: Andy Lutomirski --- arch/x86/include/asm/tlbflush.h | 6 +++++- arch/x86/mm/tlb.c | 27 --------------------------- 2 files changed, 5 insertions(+), 28 deletions(-) diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h index 6ed9ea469b48..b9db0f8fef55 100644 --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -307,11 +307,15 @@ static inline void flush_tlb_kernel_range(unsigned long start, flush_tlb_mm_range(vma->vm_mm, start, end, vma->vm_flags) extern void flush_tlb_all(void); -extern void flush_tlb_page(struct vm_area_struct *, unsigned long); extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, unsigned long end, unsigned long vmflag); extern void flush_tlb_kernel_range(unsigned long start, unsigned long end); +static inline void flush_tlb_page(struct vm_area_struct *vma, unsigned long a) +{ + flush_tlb_mm_range(vma->vm_mm, a, a + PAGE_SIZE, VM_NONE); +} + void native_flush_tlb_others(const struct cpumask *cpumask, struct mm_struct *mm, unsigned long start, unsigned long end); diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 6e7bedf69af7..fe6471132ea3 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -354,33 +354,6 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, preempt_enable(); } -void flush_tlb_page(struct vm_area_struct *vma, unsigned long start) -{ - struct mm_struct *mm = vma->vm_mm; - - preempt_disable(); - - if (current->active_mm == mm) { - if (current->mm) { - /* - * Implicit full barrier (INVLPG) that synchronizes - * with switch_mm. - */ - __flush_tlb_one(start); - } else { - leave_mm(smp_processor_id()); - - /* Synchronize with switch_mm. */ - smp_mb(); - } - } - - if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids) - flush_tlb_others(mm_cpumask(mm), mm, start, start + PAGE_SIZE); - - preempt_enable(); -} - static void do_flush_tlb_all(void *info) { count_vm_tlb_event(NR_TLB_REMOTE_FLUSH_RECEIVED); -- 2.9.3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org