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 C434DC7EE30 for ; Mon, 27 Feb 2023 22:07:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229954AbjB0WHF (ORCPT ); Mon, 27 Feb 2023 17:07:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45440 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230191AbjB0WGk (ORCPT ); Mon, 27 Feb 2023 17:06:40 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B98B28879 for ; Mon, 27 Feb 2023 14:06:38 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id B7295CE1142 for ; Mon, 27 Feb 2023 22:06:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E62FEC433A0; Mon, 27 Feb 2023 22:06:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1677535595; bh=2Y+MGv/8Qw33DQHoFGiuCv5vEDky2T0pFgaHxAPJtl4=; h=Date:To:From:Subject:From; b=nRiTGQDE6gd1AsIZO2/UA9Tl/GapXe+pujIurV2tjyg450ymj2VsL7CGUbUQrF8+6 +MLfrMaSrKkbQ9/cUjifjx94OUWxsw5lRPhw3MKSQ+kfrINy+ffl7/3LTgBObBun8S fhmDaJ/pZzlUn+l6LaVD/I0ef/9FR27+Qatv9xRM= Date: Mon, 27 Feb 2023 14:06:34 -0800 To: mm-commits@vger.kernel.org, surenb@google.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-introduce-vma-detached-flag.patch added to mm-unstable branch Message-Id: <20230227220634.E62FEC433A0@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm: introduce vma detached flag has been added to the -mm mm-unstable branch. Its filename is mm-introduce-vma-detached-flag.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-introduce-vma-detached-flag.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Suren Baghdasaryan Subject: mm: introduce vma detached flag Date: Mon, 27 Feb 2023 09:36:21 -0800 Per-vma locking mechanism will search for VMA under RCU protection and then after locking it, has to ensure it was not removed from the VMA tree after we found it. To make this check efficient, introduce a vma->detached flag to mark VMAs which were removed from the VMA tree. Link: https://lkml.kernel.org/r/20230227173632.3292573-23-surenb@google.com Signed-off-by: Suren Baghdasaryan Signed-off-by: Andrew Morton --- --- a/include/linux/mm.h~mm-introduce-vma-detached-flag +++ a/include/linux/mm.h @@ -693,6 +693,14 @@ static inline void vma_assert_write_lock VM_BUG_ON_VMA(vma->vm_lock_seq != READ_ONCE(vma->vm_mm->mm_lock_seq), vma); } +static inline void vma_mark_detached(struct vm_area_struct *vma, bool detached) +{ + /* When detaching vma should be write-locked */ + if (detached) + vma_assert_write_locked(vma); + vma->detached = detached; +} + #else /* CONFIG_PER_VMA_LOCK */ static inline void vma_init_lock(struct vm_area_struct *vma) {} @@ -701,6 +709,8 @@ static inline bool vma_start_read(struct static inline void vma_end_read(struct vm_area_struct *vma) {} static inline void vma_start_write(struct vm_area_struct *vma) {} static inline void vma_assert_write_locked(struct vm_area_struct *vma) {} +static inline void vma_mark_detached(struct vm_area_struct *vma, + bool detached) {} #endif /* CONFIG_PER_VMA_LOCK */ @@ -712,6 +722,7 @@ static inline void vma_init(struct vm_ar vma->vm_mm = mm; vma->vm_ops = &dummy_vm_ops; INIT_LIST_HEAD(&vma->anon_vma_chain); + vma_mark_detached(vma, false); vma_init_lock(vma); } --- a/include/linux/mm_types.h~mm-introduce-vma-detached-flag +++ a/include/linux/mm_types.h @@ -511,6 +511,9 @@ struct vm_area_struct { #ifdef CONFIG_PER_VMA_LOCK int vm_lock_seq; struct rw_semaphore lock; + + /* Flag to indicate areas detached from the mm->mm_mt tree */ + bool detached; #endif /* --- a/mm/mmap.c~mm-introduce-vma-detached-flag +++ a/mm/mmap.c @@ -600,6 +600,7 @@ static inline void vma_complete(struct v if (vp->remove) { again: + vma_mark_detached(vp->remove, true); if (vp->file) { uprobe_munmap(vp->remove, vp->remove->vm_start, vp->remove->vm_end); @@ -2261,6 +2262,7 @@ static inline int munmap_sidetree(struct if (mas_store_gfp(mas_detach, vma, GFP_KERNEL)) return -ENOMEM; + vma_mark_detached(vma, true); if (vma->vm_flags & VM_LOCKED) vma->vm_mm->locked_vm -= vma_pages(vma); _ Patches currently in -mm which might be from surenb@google.com are mm-introduce-config_per_vma_lock.patch mm-move-mmap_lock-assert-function-definitions.patch mm-add-per-vma-lock-and-helper-functions-to-control-it.patch mm-mark-vma-as-being-written-when-changing-vm_flags.patch mm-mmap-move-vma_prepare-before-vma_adjust_trans_huge.patch mm-khugepaged-write-lock-vma-while-collapsing-a-huge-page.patch mm-mmap-write-lock-vmas-in-vma_prepare-before-modifying-them.patch mm-mremap-write-lock-vma-while-remapping-it-to-a-new-address-range.patch mm-write-lock-vmas-before-removing-them-from-vma-tree.patch mm-conditionally-write-lock-vma-in-free_pgtables.patch kernel-fork-assert-no-vma-readers-during-its-destruction.patch mm-mmap-prevent-pagefault-handler-from-racing-with-mmu_notifier-registration.patch mm-introduce-vma-detached-flag.patch mm-introduce-lock_vma_under_rcu-to-be-used-from-arch-specific-code.patch mm-fall-back-to-mmap_lock-if-vma-anon_vma-is-not-yet-set.patch mm-add-fault_flag_vma_lock-flag.patch mm-prevent-do_swap_page-from-handling-page-faults-under-vma-lock.patch mm-prevent-userfaults-to-be-handled-under-per-vma-lock.patch mm-introduce-per-vma-lock-statistics.patch x86-mm-try-vma-lock-based-page-fault-handling-first.patch arm64-mm-try-vma-lock-based-page-fault-handling-first.patch mm-mmap-free-vm_area_struct-without-call_rcu-in-exit_mmap.patch mm-separate-vma-lock-from-vm_area_struct.patch per-vma-locks.patch