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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0EDEFE82CB3 for ; Wed, 27 Sep 2023 17:14:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9CF568D009B; Wed, 27 Sep 2023 13:14:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9587D8D0093; Wed, 27 Sep 2023 13:14:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7F9BC8D009B; Wed, 27 Sep 2023 13:14:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 6FC968D0093 for ; Wed, 27 Sep 2023 13:14:16 -0400 (EDT) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 3C227A0DAF for ; Wed, 27 Sep 2023 17:14:16 +0000 (UTC) X-FDA: 81283025712.28.8F64D85 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf16.hostedemail.com (Postfix) with ESMTP id 5FA6F18002A for ; Wed, 27 Sep 2023 17:14:14 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=uP6mOVzO; spf=pass (imf16.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1695834854; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=9zsbTfF9OJEO+DfaDPeAgMafTqHcue+0P2xvo3pdbwg=; b=D/VosOTSGX1BF/RuCBOdzpFdoNZrdCKNKoeRvmtFg0k8DpWIKtUVgkfZU1P/X4ekXs8t2l 1gPBf9X/vXYBuYTAYqK5swq6JZAOT626LkUDB+rkc6uIuGGmWtyadMtG1eBaYp9pIK0nD3 BYladJy4T3FGV02tNNTGskIbY2oJGMY= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1695834854; a=rsa-sha256; cv=none; b=VFNk5PAPLR3Oqd+DE0cu01Dn+L2Hg5oJRCFxrjS+EoGZlh2MAwxMIfuTcNX3A0uK10kKkD vmx86r1QUaRo5CNO1lxYnxrcRitL4XkN8cAPIT0YjhuMYevJC1H7jLXmoGCa84P6Khd0x3 +UcdIFUG9cc1P/6fIK6xNCHnYHjII+E= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=uP6mOVzO; spf=pass (imf16.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by ams.source.kernel.org (Postfix) with ESMTP id 8F5EDB8184F; Wed, 27 Sep 2023 17:14:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 888CDC433C8; Wed, 27 Sep 2023 17:14:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1695834851; bh=bTgktVSYX5Ufv9Td8sPF03LeSvA3mKcRwebt1XzVdvc=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=uP6mOVzO86iIZFGZxtuWQQ8i3ED5mEK1L01WNXAg6ZLNKlX1ERE6csTZku3F2GKkg rKY/e9ZqNnAezwK/wZtoQnueVrtsBPAp+F/uyPlr4D+QYbIFtDnY4zsp5YAdxMAINs RZfZyTiDk0Cj+1vv7MRuwM3s4OlVKB226Qzs3irg= Date: Wed, 27 Sep 2023 10:14:10 -0700 From: Andrew Morton To: "Liam R. Howlett" Cc: maple-tree@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Jann Horn , Lorenzo Stoakes , Vlastimil Babka , Suren Baghdasaryan , Matthew Wilcox , stable@vger.kernel.org Subject: Re: [PATCH 1/3] mmap: Fix vma_iterator in error path of vma_merge() Message-Id: <20230927101410.920fd8a88d2453f5c530aff3@linux-foundation.org> In-Reply-To: <20230927160746.1928098-2-Liam.Howlett@oracle.com> References: <20230927160746.1928098-1-Liam.Howlett@oracle.com> <20230927160746.1928098-2-Liam.Howlett@oracle.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 5FA6F18002A X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: qamrzbw4a4ohasih7f3caj381rh6atqd X-HE-Tag: 1695834854-609339 X-HE-Meta: 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 iz+kd17Z EMXjdVlaoYqypKy0mwTgPaofPGEHWIQAQ3Xg/EtqZnbNILRzfJgf6Y5LJf/bCx2AlSvG+p+mxpsBIwX7yya0pJkfS3E7MjJPq1KvEjhPans1StWWRLi0ZJSLX1/QZU6BlU8Wex9Y0VKvcxOuTzjO6kUJjUunupWnKuB+4BpGTKTYlpSfwy0AFIiQECpJgfjboNhF7q8a1F+0n3a3JMFk+EeJ0Pb0tA28qOgVBHaHqnRol+rzWCSiETt7+IYOZG8bF3K0ej7V5WYTzmrBN2a0B7S7NKTafe4HBJp5hsbpxW6ieDkARJpBZK4gWV5MQEdTa/r7JoOAAfiqLaf5RIMztdWhQunRRJ9k2KEQ32hydZ2eOmyQx8nUYBu/UU9WasMQ13RPzDgmAtDLPeDc= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, 27 Sep 2023 12:07:44 -0400 "Liam R. Howlett" wrote: > When merging of the previous VMA fails after the vma iterator has been > moved to the previous entry, the vma iterator must be advanced to ensure > the caller takes the correct action on the next vma iterator event. Fix > this by adding a vma_next() call to the error path. > > Users may experience higher CPU usage, most likely in very low memory > situations. Looking through this thread: > Closes: https://lore.kernel.org/linux-mm/CAG48ez12VN1JAOtTNMY+Y2YnsU45yL5giS-Qn=ejtiHpgJAbdQ@mail.gmail.com/ I'm seeing no indication that the effect is CPU consumption? Jann is excpecting bogus oom-killing?