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 2B444C54E58 for ; Wed, 13 Mar 2024 23:32:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8C4768D0068; Wed, 13 Mar 2024 19:32:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 84D058D0037; Wed, 13 Mar 2024 19:32:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6C6948D0068; Wed, 13 Mar 2024 19:32:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 550D38D0037 for ; Wed, 13 Mar 2024 19:32:57 -0400 (EDT) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 243A2C0920 for ; Wed, 13 Mar 2024 23:32:57 +0000 (UTC) X-FDA: 81893618394.05.A9F1221 Received: from mail-pl1-f171.google.com (mail-pl1-f171.google.com [209.85.214.171]) by imf04.hostedemail.com (Postfix) with ESMTP id 724F34000C for ; Wed, 13 Mar 2024 23:32:55 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=k0MB9W4l; spf=pass (imf04.hostedemail.com: domain of rientjes@google.com designates 209.85.214.171 as permitted sender) smtp.mailfrom=rientjes@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1710372775; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=kiJs5IjnxOl55+o3CnjBg3VVlJkoRX43JQshQZFjjM8=; b=GZN+1Z36tOsZFnZGcxLxhmkRN3xQcJSD5HHR6vy+PBbPncEAAIXwxGKGX8XI3M5qdMn0vg m3AqKmInXCvKxk6YGSo0LeNSGPnvQihWODwombjNXIQvc4QNkt2+MX6d+CTuUi93lUK21i yQL/br4rWysciqBzlAQsulnPfu/0F/o= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1710372775; a=rsa-sha256; cv=none; b=Z3sIeWMQP4m06183ue/JIJ9013iR0mC6LPNWs6GJLG6yhdB856zxJxo8GNMlGacJrvc9YE x2FaDwarmgNNTE4xmhLCv6TjUK31sn3S2b3rSQ7p/Zg5jPPYiIXLWXAqVk+bg4u9hkh8oG aZhhYgFQghaOcef4Hk3n8gM9F8m4Sbs= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=k0MB9W4l; spf=pass (imf04.hostedemail.com: domain of rientjes@google.com designates 209.85.214.171 as permitted sender) smtp.mailfrom=rientjes@google.com; dmarc=pass (policy=reject) header.from=google.com Received: by mail-pl1-f171.google.com with SMTP id d9443c01a7336-1dddd1a8732so65055ad.0 for ; Wed, 13 Mar 2024 16:32:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1710372774; x=1710977574; darn=kvack.org; h=content-id:mime-version:references:message-id:in-reply-to:subject :cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=kiJs5IjnxOl55+o3CnjBg3VVlJkoRX43JQshQZFjjM8=; b=k0MB9W4lpj3C1DfpnHqlRjDi74M0QMumo1YS5zgo4nTWye7vTLduHC9Pl2I925Dk09 uhCa+TQkw0F6tUT7KX2LkZEE1lla3i5TPIN7Ha2U4ozJyCpZT23X6Ux4Ip4isxo+FxWv eSMMylK0rXWcdCQD9FKN5jAYLqS7gMgJ6/eC7MmAsLTs8YZSldFpo3pMym1d43WlQXGH YK7QbersN+4CJhJgVO4YTC+aceFCtI5nZoxzayV35tAmY9mo1GhcNsQBh4OdRTk4cBXv 2z66F+e1PaOwKT4+hJ/+OCKZyPw/TzixouPBGHLxLTdoNMzmiO5k352LGjxh3DBe3ecD xLdw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1710372774; x=1710977574; h=content-id:mime-version:references:message-id:in-reply-to:subject :cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=kiJs5IjnxOl55+o3CnjBg3VVlJkoRX43JQshQZFjjM8=; b=qQYfzHMwKNswlz2o3c4iBxytyUZaMbeo6mXzecOdOLnrRHN/FQtvmwCh4w6VudPI8K vTZriGJcTKifubjZaxFaD9wOYnOsxFmtFI8viJQqvuuB7RvItmUAZvNNTCEulaK8dPbO GIIWHyswZWpprTVNQfZxAsYw5k3yeaoVau6YE4lrLY3XutRB+WuguOVrf3XK06SLdh+C 0OWdU8o4jbj8rzZElDWgvnwOfyO5hbUUqqI+Aslze+ZdXNx0Zt70wqtci//RHEySuZ93 mSD1fJK54CDRxZ5e/Fas+IT/eba+1P/XVmUj4J5qB5oiYIr1HbH78sos3200eocxsCBU aieg== X-Forwarded-Encrypted: i=1; AJvYcCVRMzx/34j4cC8kW2Fna//1Ix43m4OYpiqd6jvmBtxhohlWkZhQUocOeuCK9Em5wjc9M0eCwVAWpY295otvICvJQU8= X-Gm-Message-State: AOJu0YxEzTm99yb320MX+9s9JZ8WaD6hl4W4VlcWDCqgV3Sv0/1uD8+s Q59yzcbWSkYSub1/DI0IYnaKP6cPZsxorowypSjQycbfMb9sRAFRfRlMxYjRdg== X-Google-Smtp-Source: AGHT+IF5zpg3mqgIajnAZYiOJ33Dq2n+HncuYMPiwins4omF0YdE7n75wYOZ2cinolol9fIsOQX0KA== X-Received: by 2002:a17:902:d4cb:b0:1dc:dfa7:fc60 with SMTP id o11-20020a170902d4cb00b001dcdfa7fc60mr82885plg.2.1710372773902; Wed, 13 Mar 2024 16:32:53 -0700 (PDT) Received: from [2620:0:1008:15:93dd:65bc:bbd0:d2ac] ([2620:0:1008:15:93dd:65bc:bbd0:d2ac]) by smtp.gmail.com with ESMTPSA id s14-20020a63dc0e000000b005df58c83e89sm185578pgg.84.2024.03.13.16.32.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Mar 2024 16:32:53 -0700 (PDT) Date: Wed, 13 Mar 2024 16:32:52 -0700 (PDT) From: David Rientjes To: Will Deacon cc: Nanyong Sun , Catalin Marinas , Matthew Wilcox , muchun.song@linux.dev, Andrew Morton , anshuman.khandual@arm.com, wangkefeng.wang@huawei.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Yu Zhao , Yosry Ahmed , Sourav Panda Subject: Re: [PATCH v3 0/3] A Solution to Re-enable hugetlb vmemmap optimize In-Reply-To: <20240208131734.GA23428@willie-the-truck> Message-ID: References: <20240113094436.2506396-1-sunnanyong@huawei.com> <20240207111252.GA22167@willie-the-truck> <44075bc2-ac5f-ffcd-0d2f-4093351a6151@huawei.com> <20240208131734.GA23428@willie-the-truck> MIME-Version: 1.0 Content-Type: multipart/mixed; BOUNDARY="2003064516-144154717-1710372487=:1424452" Content-ID: <35d77e60-41b9-7263-4bd3-47f07a148a86@google.com> X-Rspamd-Queue-Id: 724F34000C X-Rspam-User: X-Stat-Signature: 7q6r3fnkj97cx1jgjgpqqny7ke5ewy3c X-Rspamd-Server: rspam03 X-HE-Tag: 1710372775-26009 X-HE-Meta: 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 FvcKv66e 8Yvx5holym0gj+8WoTIpL1wkJR5+SSsNYo0XdaJ5n2jbqGeSO6qLHIs71Tvqe25aEYK1zEQb+5fz3IwKVY8RbUYnmOhDTKKIVnujz7hohX6eU4MTwBh1BlMN1F6WmOiSLDZ7HbyPki/fIKUzOTHvuNfLEuQ== 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: List-Subscribe: List-Unsubscribe: This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --2003064516-144154717-1710372487=:1424452 Content-Type: text/plain; CHARSET=UTF-8 Content-Transfer-Encoding: 8BIT Content-ID: <9e36df0a-b6e1-52a5-34af-6b5859d9248f@google.com> On Thu, 8 Feb 2024, Will Deacon wrote: > > How about take a new lock with irq disabled during BBM, like: > > > > +void vmemmap_update_pte(unsigned long addr, pte_t *ptep, pte_t pte) > > +{ > > +    spin_lock_irq(NEW_LOCK); > > +    pte_clear(&init_mm, addr, ptep); > > +    flush_tlb_kernel_range(addr, addr + PAGE_SIZE); > > +    set_pte_at(&init_mm, addr, ptep, pte); > > +    spin_unlock_irq(NEW_LOCK); > > +} > > I really think the only maintainable way to achieve this is to avoid the > possibility of a fault altogether. > > Will > > Nanyong, are you still actively working on making HVO possible on arm64? This would yield a substantial memory savings on hosts that are largely configured with hugetlbfs. In our case, the size of this hugetlbfs pool is actually never changed after boot, but it sounds from the thread that there was an idea to make HVO conditional on FEAT_BBM. Is this being pursued? If so, any testing help needed? --2003064516-144154717-1710372487=:1424452--