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 4E672C7EE2D for ; Wed, 1 Mar 2023 19:05:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229471AbjCATFL (ORCPT ); Wed, 1 Mar 2023 14:05:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44302 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229656AbjCATFD (ORCPT ); Wed, 1 Mar 2023 14:05:03 -0500 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DAFF04608F for ; Wed, 1 Mar 2023 11:05:01 -0800 (PST) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-536a545bfbaso291491417b3.20 for ; Wed, 01 Mar 2023 11:05:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1677697501; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=eZZzZE8GpdNY+MwogNnFVaUs2b/RvHe7OTvEU8aJPfc=; b=Fyrl4aN8thLa08lvSwfnz3pS77dLDE/JPDoL0n+GfSBVkEYmU/na7n6N3awmHGcBsx fg4YM6nkuIRNWndpa/Vvh28BBbpGpJRQu2vsHAWiO6a5ZOUjmcMA7LOEEPP8t186icRE TTzl2f0lYKQ2gEv3faqd7R7sHmLmFHvz7aRO6WVgfOeUssnPkNyUgEAinVLSyUArDjIp kbm/6C3MBv1I4BXWlD3jhzvuaIkNNoC3TdQPTPCNNYNwWctyfsetJwP6v0E+I8n/tQPA F1L2rtHP4dGjfzEUvNlYgeld/2PRYT7D9g8oV1r1Tb8v8B8+31LZevINjOdzhGWMe5yh P0iA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1677697501; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=eZZzZE8GpdNY+MwogNnFVaUs2b/RvHe7OTvEU8aJPfc=; b=WZUEvirwD7UCbnGijsQ8TGdrO1nS5k4gOwPGR0jA+eRSnzpvQbzBOgwpNAxpiStSo+ o9k1q6GfX7k9o3qpGOcxirKcl1zaqvVfwIil/zbu+BSXR2cwMBwVp48t/bsK7lO5+zUz sfE9/6yKsZH0k2tmVMrGojzLqXLWROoupy7+XcBjFJtyJJJvgJO6wwpQP/Whau7j6GNR ILEEMH4qCRYTFrAvsTHlW/Tyc6qH1/HU+y172rTjWlpH3nuzUegsqE+UkfTkO0uLRltK Lj/NIQDHGJnnwiWyRbhXt09KqB7iuCaqTKu2UIP+zWP3qYdXr1BjcwU+0cUKPUP+YUBJ DH5w== X-Gm-Message-State: AO0yUKWVAxaR63KmU39rbt1nL/59qpDHHvR3kQq/MppIj1xJazjEZ576 0EwQ43wmicX8ES+mTAQHrsdMUHGI19U= X-Google-Smtp-Source: AK7set/9C/tFDvwQ8AH2AjoEK29ndZJWeqFhKnrMFIlBfk3w7trnnd608E+7P+Ccqu1RqtfeQNT22abiIwk= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:200:3c40:eeb3:7c3a:807e]) (user=surenb job=sendgmr) by 2002:a0d:c506:0:b0:533:b8f6:828e with SMTP id h6-20020a0dc506000000b00533b8f6828emr19ywd.411.1677697500632; Wed, 01 Mar 2023 11:05:00 -0800 (PST) Date: Wed, 1 Mar 2023 11:04:57 -0800 Mime-Version: 1.0 X-Mailer: git-send-email 2.40.0.rc0.216.gc4246ad0f0-goog Message-ID: <20230301190457.1498985-1-surenb@google.com> Subject: [PATCH 1/1] mm/nommu: remove unnecessary VMA locking 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, paulmck@kernel.org, mingo@redhat.com, will@kernel.org, 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, punit.agrawal@bytedance.com, lstoakes@gmail.com, peterjung1337@gmail.com, rientjes@google.com, chriscli@google.com, axelrasmussen@google.com, joelaf@google.com, minchan@google.com, rppt@kernel.org, jannh@google.com, shakeelb@google.com, tatashin@google.com, edumazet@google.com, gthelen@google.com, gurua@google.com, arjunroy@google.com, soheil@google.com, leewalsh@google.com, posk@google.com, michalechner92@googlemail.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org, kernel-team@android.com, Suren Baghdasaryan , Hyeonggon Yoo <42.hyeyoo@gmail.com> Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since CONFIG_PER_VMA_LOCK depends on CONFIG_MMU, the changes in nommu are not needed. Remove them. Fixes: bad94decd6a4 ("mm: write-lock VMAs before removing them from VMA tree") Reported-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Link: https://lore.kernel.org/all/Y%2F8CJQGNuMUTdLwP@localhost/ Signed-off-by: Suren Baghdasaryan --- Fix cleanly applies over mm-unstable, SHA in "Fixes" is from that tree. mm/nommu.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/mm/nommu.c b/mm/nommu.c index 2ab162d773e2..57ba243c6a37 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -588,7 +588,6 @@ static int delete_vma_from_mm(struct vm_area_struct *vma) current->pid); return -ENOMEM; } - vma_start_write(vma); cleanup_vma_from_mm(vma); /* remove from the MM's tree and list */ @@ -1520,10 +1519,6 @@ void exit_mmap(struct mm_struct *mm) */ mmap_write_lock(mm); for_each_vma(vmi, vma) { - /* - * No need to lock VMA because this is the only mm user and no - * page fault handled can race with it. - */ cleanup_vma_from_mm(vma); delete_vma(mm, vma); cond_resched(); -- 2.40.0.rc0.216.gc4246ad0f0-goog