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 E49D5C001E0 for ; Wed, 19 Jul 2023 19:21:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231171AbjGSTVl (ORCPT ); Wed, 19 Jul 2023 15:21:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49854 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231175AbjGSTVb (ORCPT ); Wed, 19 Jul 2023 15:21:31 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AC99E2136 for ; Wed, 19 Jul 2023 12:21:20 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B2F26617E5 for ; Wed, 19 Jul 2023 19:21:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 17522C433BA; Wed, 19 Jul 2023 19:21:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1689794479; bh=RsXRmd1VuXjrNMG2pLI2/0zWKR99LUUtK8Us+kVBXyg=; h=Date:To:From:Subject:From; b=GVaFNdLJnkXNS4c2e4UnZ4yl22mAYZ8r6opfJNUeY5mEJzejF7PsXdk6SH66ozMQc KJrGChnfHwUVymdqhe57Jx80ALVNQtgyxfpRPUdygYiuKjUk85C8mlD26qzzWw4AOT lgKPz1CzxUqpC7Wb259A74ryzN1je3WqwRiKge7o= Date: Wed, 19 Jul 2023 12:21:17 -0700 To: mm-commits@vger.kernel.org, torvalds@linux-foundation.org, oliver.sang@intel.com, Liam.Howlett@oracle.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-mmap-change-detached-vma-locking-scheme.patch added to mm-unstable branch Message-Id: <20230719192119.17522C433BA@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/mmap: change detached vma locking scheme has been added to the -mm mm-unstable branch. Its filename is mm-mmap-change-detached-vma-locking-scheme.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mmap-change-detached-vma-locking-scheme.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: "Liam R. Howlett" Subject: mm/mmap: change detached vma locking scheme Date: Wed, 5 Jul 2023 14:47:49 -0400 Don't set the lock to the mm lock so that the detached VMA tree does not complain about being unlocked when the mmap_lock is dropped prior to freeing the tree. Introduce mt_on_stack() for setting the external lock to NULL only when LOCKDEP is used. Move the destroying of the detached tree outside the mmap lock all together. Link: https://lkml.kernel.org/r/20230719183142.ktgcmuj2pnlr3h3s@revolver Signed-off-by: Liam R. Howlett Cc: Linus Torvalds Cc: Oliver Sang Signed-off-by: Andrew Morton --- include/linux/maple_tree.h | 3 +++ mm/mmap.c | 4 ++-- 2 files changed, 5 insertions(+), 2 deletions(-) --- a/include/linux/maple_tree.h~mm-mmap-change-detached-vma-locking-scheme +++ a/include/linux/maple_tree.h @@ -187,10 +187,13 @@ typedef struct lockdep_map *lockdep_map_ #define mt_set_external_lock(mt, lock) \ (mt)->ma_external_lock = &(lock)->dep_map + +#define mt_on_stack(mt) (mt).ma_external_lock = NULL #else typedef struct { /* nothing */ } lockdep_map_p; #define mt_lock_is_held(mt) 1 #define mt_set_external_lock(mt, lock) do { } while (0) +#define mt_on_stack(mt) do { } while (0) #endif /* --- a/mm/mmap.c~mm-mmap-change-detached-vma-locking-scheme +++ a/mm/mmap.c @@ -2427,7 +2427,7 @@ do_vmi_align_munmap(struct vma_iterator unsigned long locked_vm = 0; MA_STATE(mas_detach, &mt_detach, 0, 0); mt_init_flags(&mt_detach, vmi->mas.tree->ma_flags & MT_FLAGS_LOCK_MASK); - mt_set_external_lock(&mt_detach, &mm->mmap_lock); + mt_on_stack(mt_detach); /* * If we need to split any vma, do it now to save pain later. @@ -2545,11 +2545,11 @@ do_vmi_align_munmap(struct vma_iterator /* Statistics and freeing VMAs */ mas_set(&mas_detach, start); remove_mt(mm, &mas_detach); - __mt_destroy(&mt_detach); validate_mm(mm); if (unlock) mmap_read_unlock(mm); + __mt_destroy(&mt_detach); return 0; clear_tree_failed: _ Patches currently in -mm which might be from Liam.Howlett@oracle.com are mm-mmap-clean-up-validate_mm-calls.patch maple_tree-relax-lockdep-checks-for-on-stack-trees.patch mm-mmap-change-detached-vma-locking-scheme.patch maple_tree-be-more-strict-about-locking.patch