From patchwork Wed Mar 1 19:04:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suren Baghdasaryan X-Patchwork-Id: 63040 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:5915:0:0:0:0:0 with SMTP id v21csp3816444wrd; Wed, 1 Mar 2023 11:13:19 -0800 (PST) X-Google-Smtp-Source: AK7set8ZfmB6ABhzptmMxP6TpISjys0A9sz4dBKMUJxEtgCjTS4npx1bo8BjftOqiJ7DzkPN6Iqq X-Received: by 2002:a17:90b:350b:b0:233:fdfd:7122 with SMTP id ls11-20020a17090b350b00b00233fdfd7122mr8620535pjb.37.1677697999444; Wed, 01 Mar 2023 11:13:19 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1677697999; cv=none; d=google.com; s=arc-20160816; b=lJ7hxnnFu9GQOFIBruxRdNtzxWsTTEwI4vcMnpkeQRnxwr3nYQIr7h5mCBJ0zAQFDq 2tANTZ5kUV8R4WvegUxk6e/ur9YoQa3E+Xhp5fFUoZwa7LuFFHchsNd3Tn478Al1N3Ze 7uqjQhq3N0y1GJcGCW2xCDcfFncgW18+7GVvpFtzbo++Dua3qJgAoC046BKulJryEcxR vKZEIF/POu7gT1YlR65Yjs2+isXNsqVhVTe7lnCePvBYuw8w7iT5zhhVw3onZLV9v0zY O1zGU7AO457aXFvhdwMKt99EwnZUUmvHE1j8+GFNMmRkHLN5ATtM6jOTpISMqosUuhbl uQ4A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:cc:to:from:subject:message-id:mime-version:date :dkim-signature; bh=eZZzZE8GpdNY+MwogNnFVaUs2b/RvHe7OTvEU8aJPfc=; b=kg1VFvGjU19vxRM5MwWxKLCuaPuPPf3C4Ddw37yNoeahtRQ94zTVP9Fa/cx20Cndon DbjzR25XHt1imD4zkIq1UKdkfCD669hGCC2slMppTC7JC+Dw1XnKYUhUd/YO4z/O2BwE PH0Sf24Xm9+gt5DElAqUboJJ//vkgANqiyJVbz7CYMLDYoN1kSpPZ0piT8mS2yCzYbbF UOfxyLB+LTtXXYCbSPtG7qcy+zbQTQk+G/Zg8DEG9uLXqtdFCHCg2flx+isgAq2RsryY j6umlrh8llfyaEeZ7VfN8BoTaCStJkrdGd4cE5KOGFcSG+c+JP7J59dI8JsYsLgJM/8H 31CA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=Fyrl4aN8; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id s69-20020a632c48000000b004acd11feb3csi13313428pgs.607.2023.03.01.11.12.48; Wed, 01 Mar 2023 11:13:19 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=Fyrl4aN8; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229676AbjCATFK (ORCPT + 99 others); Wed, 1 Mar 2023 14:05:10 -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-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> X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1759193857721377149?= X-GMAIL-MSGID: =?utf-8?q?1759193857721377149?= 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 Reviewed-by: David Hildenbrand --- 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();