From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B62E7ECDE5F for ; Mon, 23 Jul 2018 12:46:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 72EE420685 for ; Mon, 23 Jul 2018 12:46:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 72EE420685 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388863AbeGWNrR (ORCPT ); Mon, 23 Jul 2018 09:47:17 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:50770 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388007AbeGWNrR (ORCPT ); Mon, 23 Jul 2018 09:47:17 -0400 Received: from localhost (LFbn-1-12238-233.w90-92.abo.wanadoo.fr [90.92.53.233]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 055E7CA1; Mon, 23 Jul 2018 12:44:09 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andy Lutomirski , Nadav Amit , Thomas Gleixner , Andrew Morton , Arjan van de Ven , Borislav Petkov , Dave Hansen , Linus Torvalds , Mel Gorman , Peter Zijlstra , Rik van Riel , linux-mm@kvack.org, Ingo Molnar , Tim Chen , "Srivatsa S. Bhat" , "Matt Helsley (VMware)" , Alexey Makhalov , Bo Gan Subject: [PATCH 4.4 038/107] x86/mm: Give each mm TLB flush generation a unique ID Date: Mon, 23 Jul 2018 14:41:32 +0200 Message-Id: <20180723122414.789067704@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180723122413.003644357@linuxfoundation.org> References: <20180723122413.003644357@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Lutomirski commit f39681ed0f48498b80455095376f11535feea332 upstream. This adds two new variables to mmu_context_t: ctx_id and tlb_gen. ctx_id uniquely identifies the mm_struct and will never be reused. For a given mm_struct (and hence ctx_id), tlb_gen is a monotonic count of the number of times that a TLB flush has been requested. The pair (ctx_id, tlb_gen) can be used as an identifier for TLB flush actions and will be used in subsequent patches to reliably determine whether all needed TLB flushes have occurred on a given CPU. This patch is split out for ease of review. By itself, it has no real effect other than creating and updating the new variables. Signed-off-by: Andy Lutomirski Reviewed-by: Nadav Amit Reviewed-by: Thomas Gleixner Cc: Andrew Morton Cc: Arjan van de Ven Cc: Borislav Petkov Cc: Dave Hansen Cc: Linus Torvalds Cc: Mel Gorman Cc: Peter Zijlstra Cc: Rik van Riel Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/413a91c24dab3ed0caa5f4e4d017d87b0857f920.1498751203.git.luto@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Tim Chen Signed-off-by: Greg Kroah-Hartman Signed-off-by: Srivatsa S. Bhat Reviewed-by: Matt Helsley (VMware) Reviewed-by: Alexey Makhalov Reviewed-by: Bo Gan Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/mmu.h | 15 +++++++++++++-- arch/x86/include/asm/mmu_context.h | 4 ++++ arch/x86/mm/tlb.c | 2 ++ 3 files changed, 19 insertions(+), 2 deletions(-) --- a/arch/x86/include/asm/mmu.h +++ b/arch/x86/include/asm/mmu.h @@ -3,12 +3,18 @@ #include #include +#include /* - * The x86 doesn't have a mmu context, but - * we put the segment information here. + * x86 has arch-specific MMU state beyond what lives in mm_struct. */ typedef struct { + /* + * ctx_id uniquely identifies this mm_struct. A ctx_id will never + * be reused, and zero is not a valid ctx_id. + */ + u64 ctx_id; + #ifdef CONFIG_MODIFY_LDT_SYSCALL struct ldt_struct *ldt; #endif @@ -24,6 +30,11 @@ typedef struct { atomic_t perf_rdpmc_allowed; /* nonzero if rdpmc is allowed */ } mm_context_t; +#define INIT_MM_CONTEXT(mm) \ + .context = { \ + .ctx_id = 1, \ + } + void leave_mm(int cpu); #endif /* _ASM_X86_MMU_H */ --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -11,6 +11,9 @@ #include #include #include + +extern atomic64_t last_mm_ctx_id; + #ifndef CONFIG_PARAVIRT static inline void paravirt_activate_mm(struct mm_struct *prev, struct mm_struct *next) @@ -105,6 +108,7 @@ static inline void enter_lazy_tlb(struct static inline int init_new_context(struct task_struct *tsk, struct mm_struct *mm) { + mm->context.ctx_id = atomic64_inc_return(&last_mm_ctx_id); init_new_context_ldt(tsk, mm); return 0; } --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -29,6 +29,8 @@ * Implement flush IPI by CALL_FUNCTION_VECTOR, Alex Shi */ +atomic64_t last_mm_ctx_id = ATOMIC64_INIT(1); + struct flush_tlb_info { struct mm_struct *flush_mm; unsigned long flush_start;