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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3DE85ECAAD4 for ; Mon, 29 Aug 2022 21:25:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229475AbiH2VZu (ORCPT ); Mon, 29 Aug 2022 17:25:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59994 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229682AbiH2VZl (ORCPT ); Mon, 29 Aug 2022 17:25:41 -0400 Received: from mail-pj1-x1049.google.com (mail-pj1-x1049.google.com [IPv6:2607:f8b0:4864:20::1049]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 28E5ED53 for ; Mon, 29 Aug 2022 14:25:39 -0700 (PDT) Received: by mail-pj1-x1049.google.com with SMTP id n30-20020a17090a5aa100b001fb0c492d5eso3876529pji.3 for ; Mon, 29 Aug 2022 14:25:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc; bh=cPhW2Jsm5VYfGL+tNkfF3HbuaaNlLZ4rflaa6thsEZ0=; b=Ef83aGWTdm10niN8twSSpG3ds5UuJPZXIlmBxHFg2pzrVEdcovVnDh3P/RYOinFzyL 56g3s4OBiiWq4sYS4zyOn+I3sJdcQzzrlMjpsAwGpe/6DNb56LumMLV46gfcGkdOoroQ Xn2Ez1+n3LVumJ9ul/e3Fo4g/eC812QXSiR/GOAlZ/X37IBJZ8GhOEEF+zxhXhrBOhrA wyQ3RxsgNeUblE3TddZPmpCUfJPQ1JoHkMsqbRXnrreQjskaAOAntkxj5MpJLWS1ppBQ s3y364HBN4NsSi7BBvtTGWNjoBJVZ6VaguwCOOzVv7z+u5EVx5HkEViGicNoS6cS9car 5ukQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc; bh=cPhW2Jsm5VYfGL+tNkfF3HbuaaNlLZ4rflaa6thsEZ0=; b=vUCD+/JSTxgS+AoyvoIDXIUt01raJEQlBSaZpvI6jplZP6B1Q4OEAeMAqcBp0SgtUi EcTqYFYNv2ca1RZJr9KWHoOT2saek8Cz+gD9DGQ7iEQF2zt3GJC7f9X29yoHMq4piVf6 xDIfepskCEvaXpuWcGC3aQ/xvnUDvjTkp3dEGcF0l8Gw/HP8dp/W8RIG21Gt/BMaAktz pvVQvM644X2iMRH6Raupdq2qQU5w1fTeJzSG3ha6LVqlIdjqmZ15QV1nz7+tMfLnxSC7 5K+VFYsZ3bzHmtPVfrv3YWsFLhiR7OLiHyX3rTKHWcY1bLRLqfPjrzTzloprg8Hmq2kA dvGA== X-Gm-Message-State: ACgBeo2uOf5/c/tGHAbA0727BoEKXzPv3a29VlUGs2f1p2zARP7B25vq RXI6kv9TPRZHV2gd/dZya8nvIHk+HatCUt/Wf9Iad+eqv1mdua3IPeCUlME6q3suIiGque3/lbx rkpqoz7Jt2E97FMPrjDBc X-Google-Smtp-Source: AA6agR4h8d6XU8wf7Rba89JuzvO6/M5QQD9xRgO2erAMFyngZx2nEIGpax2LUa1YM3lFKVFmr9HgbHhBg9U= X-Received: from surenb-spec.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:3e30]) (user=surenb job=sendgmr) by 2002:a17:902:694a:b0:16e:e270:1f84 with SMTP id k10-20020a170902694a00b0016ee2701f84mr17988146plt.89.1661808339339; Mon, 29 Aug 2022 14:25:39 -0700 (PDT) Date: Mon, 29 Aug 2022 21:25:05 +0000 In-Reply-To: <20220829212531.3184856-1-surenb@google.com> Mime-Version: 1.0 References: <20220829212531.3184856-1-surenb@google.com> X-Mailer: git-send-email 2.37.2.672.g94769d06f0-goog Message-ID: <20220829212531.3184856-3-surenb@google.com> Subject: [RFC PATCH 02/28] mm: rcu safe VMA freeing From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: michel@lespinasse.org, jglisse@google.com, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, mgorman@techsingularity.net, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, peterz@infradead.org, ldufour@linux.ibm.com, laurent.dufour@fr.ibm.com, paulmck@kernel.org, riel@surriel.com, luto@kernel.org, songliubraving@fb.com, peterx@redhat.com, david@redhat.com, dhowells@redhat.com, hughd@google.com, bigeasy@linutronix.de, kent.overstreet@linux.dev, rientjes@google.com, axelrasmussen@google.com, joelaf@google.com, minchan@google.com, surenb@google.com, kernel-team@android.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" X-ccpol: medium Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Michel Lespinasse This prepares for page faults handling under VMA lock, looking up VMAs under protection of an rcu read lock, instead of the usual mmap read lock. Signed-off-by: Michel Lespinasse Signed-off-by: Suren Baghdasaryan --- include/linux/mm_types.h | 16 +++++++++++----- kernel/fork.c | 13 +++++++++++++ 2 files changed, 24 insertions(+), 5 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index cf97f3884fda..bed25ef7c994 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -403,12 +403,18 @@ struct anon_vma_name { struct vm_area_struct { /* The first cache line has the info for VMA tree walking. */ - unsigned long vm_start; /* Our start address within vm_mm. */ - unsigned long vm_end; /* The first byte after our end address - within vm_mm. */ + union { + struct { + /* VMA covers [vm_start; vm_end) addresses within mm */ + unsigned long vm_start, vm_end; - /* linked list of VM areas per task, sorted by address */ - struct vm_area_struct *vm_next, *vm_prev; + /* linked list of VMAs per task, sorted by address */ + struct vm_area_struct *vm_next, *vm_prev; + }; +#ifdef CONFIG_PER_VMA_LOCK + struct rcu_head vm_rcu; /* Used for deferred freeing. */ +#endif + }; struct rb_node vm_rb; diff --git a/kernel/fork.c b/kernel/fork.c index 90c85b17bf69..614872438393 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -481,10 +481,23 @@ struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig) return new; } +#ifdef CONFIG_PER_VMA_LOCK +static void __vm_area_free(struct rcu_head *head) +{ + struct vm_area_struct *vma = container_of(head, struct vm_area_struct, + vm_rcu); + kmem_cache_free(vm_area_cachep, vma); +} +#endif + void vm_area_free(struct vm_area_struct *vma) { free_anon_vma_name(vma); +#ifdef CONFIG_PER_VMA_LOCK + call_rcu(&vma->vm_rcu, __vm_area_free); +#else kmem_cache_free(vm_area_cachep, vma); +#endif } static void account_kernel_stack(struct task_struct *tsk, int account) -- 2.37.2.672.g94769d06f0-goog 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 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4BD8BECAAD2 for ; Mon, 29 Aug 2022 22:02:44 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4MGkvQ6PwPz3dpB for ; Tue, 30 Aug 2022 08:02:42 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20210112 header.b=Ef83aGWT; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=flex--surenb.bounces.google.com (client-ip=2607:f8b0:4864:20::64a; helo=mail-pl1-x64a.google.com; envelope-from=30y4nywykdiq02zmvjowwotm.kwutqv25xxk-lm3tq010.w7tij0.wzo@flex--surenb.bounces.google.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20210112 header.b=Ef83aGWT; dkim-atps=neutral Received: from mail-pl1-x64a.google.com (mail-pl1-x64a.google.com [IPv6:2607:f8b0:4864:20::64a]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4MGk4k5Ykxz3bVt for ; Tue, 30 Aug 2022 07:25:41 +1000 (AEST) Received: by mail-pl1-x64a.google.com with SMTP id m14-20020a170902db0e00b0017336b7f6b9so6725897plx.5 for ; Mon, 29 Aug 2022 14:25:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc; bh=cPhW2Jsm5VYfGL+tNkfF3HbuaaNlLZ4rflaa6thsEZ0=; b=Ef83aGWTdm10niN8twSSpG3ds5UuJPZXIlmBxHFg2pzrVEdcovVnDh3P/RYOinFzyL 56g3s4OBiiWq4sYS4zyOn+I3sJdcQzzrlMjpsAwGpe/6DNb56LumMLV46gfcGkdOoroQ Xn2Ez1+n3LVumJ9ul/e3Fo4g/eC812QXSiR/GOAlZ/X37IBJZ8GhOEEF+zxhXhrBOhrA wyQ3RxsgNeUblE3TddZPmpCUfJPQ1JoHkMsqbRXnrreQjskaAOAntkxj5MpJLWS1ppBQ s3y364HBN4NsSi7BBvtTGWNjoBJVZ6VaguwCOOzVv7z+u5EVx5HkEViGicNoS6cS9car 5ukQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc; bh=cPhW2Jsm5VYfGL+tNkfF3HbuaaNlLZ4rflaa6thsEZ0=; b=M85YHqV9PirRv6mmkdgL/ERRQrRwku55inkbWhB1J+szxDxs3bpJMnwtV11KSbatE8 016w+G7xPDGWOvWtzIbpVjLYlJtfVo2jyKCAEtnFsGsi4lxjGrJhwhTolWCHpzlRMBrC 2FjSx2mxdsI30WWuW5d7c2DBywn5kfOerHT4GV54kj16i9saLXVbd8ZNv75gXi1Bo2sL VK5/cH0SSiO87MmTLPQ6UGgtNHpeHi58FSmFpsaWeWDXiwUy03ef0EnROvKai/ZwXPuU 50qiaxCzeeKGENEPGku4mqRaxnTt5D5SW5l0PSnTNZIkIKESQptHwFvo93LlRuQVzEW9 lS+Q== X-Gm-Message-State: ACgBeo3rWY8Cm65laBsNh4f8ndMv7QGZIQDP4L0Z+1D5Xz95jv/WGil6 cZ6eZ+fCcI8mqFZHJAcme5N/ezgubZChxIjkHS+ek/NYjBAkHVXMEHkCiTOra5lbA8YApbpWnCa vIQY4EL1AEg1P4XVvsOo82w== X-Google-Smtp-Source: AA6agR4h8d6XU8wf7Rba89JuzvO6/M5QQD9xRgO2erAMFyngZx2nEIGpax2LUa1YM3lFKVFmr9HgbHhBg9U= X-Received: from surenb-spec.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:3e30]) (user=surenb job=sendgmr) by 2002:a17:902:694a:b0:16e:e270:1f84 with SMTP id k10-20020a170902694a00b0016ee2701f84mr17988146plt.89.1661808339339; Mon, 29 Aug 2022 14:25:39 -0700 (PDT) Date: Mon, 29 Aug 2022 21:25:05 +0000 In-Reply-To: <20220829212531.3184856-1-surenb@google.com> Mime-Version: 1.0 References: <20220829212531.3184856-1-surenb@google.com> X-Mailer: git-send-email 2.37.2.672.g94769d06f0-goog Message-ID: <20220829212531.3184856-3-surenb@google.com> Subject: [RFC PATCH 02/28] mm: rcu safe VMA freeing From: Suren Baghdasaryan To: akpm@linux-foundation.org Content-Type: text/plain; charset="UTF-8" X-ccpol: medium X-Mailman-Approved-At: Tue, 30 Aug 2022 08:01:45 +1000 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: michel@lespinasse.org, joelaf@google.com, songliubraving@fb.com, mhocko@suse.com, david@redhat.com, peterz@infradead.org, bigeasy@linutronix.de, peterx@redhat.com, dhowells@redhat.com, linux-mm@kvack.org, jglisse@google.com, dave@stgolabs.net, minchan@google.com, x86@kernel.org, hughd@google.com, willy@infradead.org, laurent.dufour@fr.ibm.com, linux-arm-kernel@lists.infradead.org, rientjes@google.com, axelrasmussen@google.com, kernel-team@android.com, paulmck@kernel.org, riel@surriel.com, liam.howlett@oracle.com, luto@kernel.org, ldufour@linux.ibm.com, surenb@google.com, vbabka@suse.cz, linuxppc-dev@lists.ozlabs.org, kent.overstreet@linux.dev, linux-kernel@vger.kernel.org, hannes@cmpxchg.org, mgorman@techsingularity.net Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Michel Lespinasse This prepares for page faults handling under VMA lock, looking up VMAs under protection of an rcu read lock, instead of the usual mmap read lock. Signed-off-by: Michel Lespinasse Signed-off-by: Suren Baghdasaryan --- include/linux/mm_types.h | 16 +++++++++++----- kernel/fork.c | 13 +++++++++++++ 2 files changed, 24 insertions(+), 5 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index cf97f3884fda..bed25ef7c994 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -403,12 +403,18 @@ struct anon_vma_name { struct vm_area_struct { /* The first cache line has the info for VMA tree walking. */ - unsigned long vm_start; /* Our start address within vm_mm. */ - unsigned long vm_end; /* The first byte after our end address - within vm_mm. */ + union { + struct { + /* VMA covers [vm_start; vm_end) addresses within mm */ + unsigned long vm_start, vm_end; - /* linked list of VM areas per task, sorted by address */ - struct vm_area_struct *vm_next, *vm_prev; + /* linked list of VMAs per task, sorted by address */ + struct vm_area_struct *vm_next, *vm_prev; + }; +#ifdef CONFIG_PER_VMA_LOCK + struct rcu_head vm_rcu; /* Used for deferred freeing. */ +#endif + }; struct rb_node vm_rb; diff --git a/kernel/fork.c b/kernel/fork.c index 90c85b17bf69..614872438393 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -481,10 +481,23 @@ struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig) return new; } +#ifdef CONFIG_PER_VMA_LOCK +static void __vm_area_free(struct rcu_head *head) +{ + struct vm_area_struct *vma = container_of(head, struct vm_area_struct, + vm_rcu); + kmem_cache_free(vm_area_cachep, vma); +} +#endif + void vm_area_free(struct vm_area_struct *vma) { free_anon_vma_name(vma); +#ifdef CONFIG_PER_VMA_LOCK + call_rcu(&vma->vm_rcu, __vm_area_free); +#else kmem_cache_free(vm_area_cachep, vma); +#endif } static void account_kernel_stack(struct task_struct *tsk, int account) -- 2.37.2.672.g94769d06f0-goog 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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A2F9BECAAD2 for ; Mon, 29 Aug 2022 22:35:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:From:Subject:Message-ID: References:Mime-Version:In-Reply-To:Date:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=/cctgxXx5p+wLt2fVrlHloOXlXKWDtJLB0a8oPyJdOQ=; b=xMf2r5Qz5viPMuYOAN2T+ZsTpa 4GV1aJA1gJ8UpO+vo99cHEARRFX8GkNXb4P5HRfpGznHs6gGZR1p1ZM9b8duDtsgLuOAreTtQjStD cYDPAeFXsa0qmIZ5cozpMNlTPkgNjOaxO4HAKhNOiE2DifmaMTLv30qyR2ykVDLNYtLLs6M7d7siT cc7ATH4+ep0mxpj8mGgXuwD9Xc8Th3cwwtwrH1I0OUa68SvI56QLbJJKGnNwITeFi9Jn7tWnvYO8C 0GCX4xrcHG151WUwkmtBgKsScBcNNPbyQfs0J1YbMBodvMqQyAggTr1BT4K3DGVaS0uF+dULloUX+ 6ef4lotg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oSnLR-00D4Qs-S8; Mon, 29 Aug 2022 22:35:02 +0000 Received: from mail-pl1-x649.google.com ([2607:f8b0:4864:20::649]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oSmGK-00Cn5k-JR for linux-arm-kernel@lists.infradead.org; Mon, 29 Aug 2022 21:25:42 +0000 Received: by mail-pl1-x649.google.com with SMTP id q6-20020a17090311c600b0017266460b8fso6784160plh.4 for ; Mon, 29 Aug 2022 14:25:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc; bh=cPhW2Jsm5VYfGL+tNkfF3HbuaaNlLZ4rflaa6thsEZ0=; b=Ef83aGWTdm10niN8twSSpG3ds5UuJPZXIlmBxHFg2pzrVEdcovVnDh3P/RYOinFzyL 56g3s4OBiiWq4sYS4zyOn+I3sJdcQzzrlMjpsAwGpe/6DNb56LumMLV46gfcGkdOoroQ Xn2Ez1+n3LVumJ9ul/e3Fo4g/eC812QXSiR/GOAlZ/X37IBJZ8GhOEEF+zxhXhrBOhrA wyQ3RxsgNeUblE3TddZPmpCUfJPQ1JoHkMsqbRXnrreQjskaAOAntkxj5MpJLWS1ppBQ s3y364HBN4NsSi7BBvtTGWNjoBJVZ6VaguwCOOzVv7z+u5EVx5HkEViGicNoS6cS9car 5ukQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc; bh=cPhW2Jsm5VYfGL+tNkfF3HbuaaNlLZ4rflaa6thsEZ0=; b=MZtAsLQ6MdPzqpCGxnQipftuCmPfq4J0M4AoLA4YcQ5QbsBs49bAFxFyfNjzijDkGt sWF5ofciOg5xtcw3LQJGwiZQoMiJVSBY6jhf5TfWCisnf0qJCPqI/L2y0sPayI9mKbdI QiL4OQGLoPbfZYEEJ9mG+kje58MFueHTK53QUBiIMoNhurxg7ZcXFVLRL/U9rcCdcaD2 gJDYL9E9AB1HrMiOcW0SkjleElN2vEG8YYUBBEkq+8kCNmphUOR6RFPopTJkbPBXTF96 dL/l0iE/37YuXpllHYTp/G6SkfsEJ6vG6yCdTDS5ZRv9VVYdFtZPgv+fSF/Im0rXFnfp 2l3w== X-Gm-Message-State: ACgBeo0zE8WDhCWY6VfE7pQ8ZvNWetBESdMYQTWXrKx5IBHKoA0JsSNu HMGR8CkCmQEU67idBr6C4zakrGioXz5rNqAb0wyLDg6vtPiFY3ViP8D2RiBp4f8ocW0k+eYmhLE OyAhyRiZtTlQPC8I/aThKKHqpCHcGNoU= X-Google-Smtp-Source: AA6agR4h8d6XU8wf7Rba89JuzvO6/M5QQD9xRgO2erAMFyngZx2nEIGpax2LUa1YM3lFKVFmr9HgbHhBg9U= X-Received: from surenb-spec.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:3e30]) (user=surenb job=sendgmr) by 2002:a17:902:694a:b0:16e:e270:1f84 with SMTP id k10-20020a170902694a00b0016ee2701f84mr17988146plt.89.1661808339339; Mon, 29 Aug 2022 14:25:39 -0700 (PDT) Date: Mon, 29 Aug 2022 21:25:05 +0000 In-Reply-To: <20220829212531.3184856-1-surenb@google.com> Mime-Version: 1.0 References: <20220829212531.3184856-1-surenb@google.com> X-Mailer: git-send-email 2.37.2.672.g94769d06f0-goog Message-ID: <20220829212531.3184856-3-surenb@google.com> Subject: [RFC PATCH 02/28] mm: rcu safe VMA freeing From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: michel@lespinasse.org, jglisse@google.com, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, mgorman@techsingularity.net, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, peterz@infradead.org, ldufour@linux.ibm.com, laurent.dufour@fr.ibm.com, paulmck@kernel.org, riel@surriel.com, luto@kernel.org, songliubraving@fb.com, peterx@redhat.com, david@redhat.com, dhowells@redhat.com, hughd@google.com, bigeasy@linutronix.de, kent.overstreet@linux.dev, rientjes@google.com, axelrasmussen@google.com, joelaf@google.com, minchan@google.com, surenb@google.com, kernel-team@android.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org X-ccpol: medium X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220829_142540_676244_482E0566 X-CRM114-Status: GOOD ( 14.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Michel Lespinasse This prepares for page faults handling under VMA lock, looking up VMAs under protection of an rcu read lock, instead of the usual mmap read lock. Signed-off-by: Michel Lespinasse Signed-off-by: Suren Baghdasaryan --- include/linux/mm_types.h | 16 +++++++++++----- kernel/fork.c | 13 +++++++++++++ 2 files changed, 24 insertions(+), 5 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index cf97f3884fda..bed25ef7c994 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -403,12 +403,18 @@ struct anon_vma_name { struct vm_area_struct { /* The first cache line has the info for VMA tree walking. */ - unsigned long vm_start; /* Our start address within vm_mm. */ - unsigned long vm_end; /* The first byte after our end address - within vm_mm. */ + union { + struct { + /* VMA covers [vm_start; vm_end) addresses within mm */ + unsigned long vm_start, vm_end; - /* linked list of VM areas per task, sorted by address */ - struct vm_area_struct *vm_next, *vm_prev; + /* linked list of VMAs per task, sorted by address */ + struct vm_area_struct *vm_next, *vm_prev; + }; +#ifdef CONFIG_PER_VMA_LOCK + struct rcu_head vm_rcu; /* Used for deferred freeing. */ +#endif + }; struct rb_node vm_rb; diff --git a/kernel/fork.c b/kernel/fork.c index 90c85b17bf69..614872438393 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -481,10 +481,23 @@ struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig) return new; } +#ifdef CONFIG_PER_VMA_LOCK +static void __vm_area_free(struct rcu_head *head) +{ + struct vm_area_struct *vma = container_of(head, struct vm_area_struct, + vm_rcu); + kmem_cache_free(vm_area_cachep, vma); +} +#endif + void vm_area_free(struct vm_area_struct *vma) { free_anon_vma_name(vma); +#ifdef CONFIG_PER_VMA_LOCK + call_rcu(&vma->vm_rcu, __vm_area_free); +#else kmem_cache_free(vm_area_cachep, vma); +#endif } static void account_kernel_stack(struct task_struct *tsk, int account) -- 2.37.2.672.g94769d06f0-goog _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel