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 A4A2FC001E0 for ; Thu, 10 Aug 2023 17:35:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1F71F6B0071; Thu, 10 Aug 2023 13:35:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1A7216B0072; Thu, 10 Aug 2023 13:35:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 020416B0075; Thu, 10 Aug 2023 13:35:36 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id E7A4A6B0071 for ; Thu, 10 Aug 2023 13:35:36 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id B1B7D1A0AA8 for ; Thu, 10 Aug 2023 17:35:36 +0000 (UTC) X-FDA: 81108897072.14.AB01F9A Received: from mail-qt1-f175.google.com (mail-qt1-f175.google.com [209.85.160.175]) by imf13.hostedemail.com (Postfix) with ESMTP id F28E420014 for ; Thu, 10 Aug 2023 17:35:34 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=google.com header.s=20221208 header.b="GUrYcJE/"; spf=pass (imf13.hostedemail.com: domain of yuzhao@google.com designates 209.85.160.175 as permitted sender) smtp.mailfrom=yuzhao@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=1691688935; 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=C4zR+h8gNj84hzvJdKLVYf0Oy4aj291OIfrsJBN6e1k=; b=Fh3pP9eWCICujX/QuV70Gx2JHcJGZ5XNg+aE/s3ik7JbleLTPMX73y39bgKPbt66Vh3ijJ jcy9X9ylB4Rfqn7qgtCxEegwYDUu8N9eXlJDNRRzuliwNrF3xEc9jdq8TdmnbAW9BuKOKs f1G8eJiuthVY5yXEHRWtLST3LcYvtVI= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1691688935; a=rsa-sha256; cv=none; b=fVa9BH0oYqt1Lyh5Tt4sWedJooegkqeCVLVy42LZxu+OhnJ6QldMaPUIraiyI6/lXca1iK P8XNUxW5rDuMCUqdf55cIU2/yAkictRokd3zl0UaezT3AXSsTnnsV7bWUgF0Zd8wgIAzZK d7/abFpfmAdYGtMVHzBRKxQ8jP6GiMM= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=google.com header.s=20221208 header.b="GUrYcJE/"; spf=pass (imf13.hostedemail.com: domain of yuzhao@google.com designates 209.85.160.175 as permitted sender) smtp.mailfrom=yuzhao@google.com; dmarc=pass (policy=reject) header.from=google.com Received: by mail-qt1-f175.google.com with SMTP id d75a77b69052e-4036bd4fff1so33881cf.0 for ; Thu, 10 Aug 2023 10:35:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1691688934; x=1692293734; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=C4zR+h8gNj84hzvJdKLVYf0Oy4aj291OIfrsJBN6e1k=; b=GUrYcJE/mWeEfk2Hkl8lGPsqBr4CZk8xwjk3wmkQqyJwVAQiTIn8X4m9LQhiD+9QKZ czxzsndcjdyigOZnT+HPES6lXU3Kz5l7Cn5ZDeNXV8qOemAWnHLBKDTH4xEOrL/jx732 XIjAhjOv/EUfkKleDG6LhXnyKlJudM4mOyInWMkjhUjKs3y96jrAc0cXuiAviFdz259L mWvW+f31bKP7k/w0QBtGWlDpF4ukxytniEquEUrRIh7Ls6EEq0SX3AWSi9lBbNKOfpgZ XkRLTDJ0JlEpPkepz0ja++eDkwufhJ22bTecsAXZAnX3G8m7RhtSwQc2TPaCHdAGAefe FeJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691688934; x=1692293734; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=C4zR+h8gNj84hzvJdKLVYf0Oy4aj291OIfrsJBN6e1k=; b=RZ1yYnwzFWInpx+b7xfG7Dg+kbaf1cqytl/j0DzfLRJdCQMcutRulyhw5T+mR9M+SW aNKnTBen4TpHD0CxLVIS/VK3AfjIbnPRCa2/ZDFInkpTgysGpYLt5z2RqryPlj3Malvv z+KXuOdIrv2uBWavYWOv6ZtRg0gBiQMFeTLAmh5pu65uktouoREgdwacTSoODZZw6vKQ gCAw2BU9o5NqOHxo5zkddacDm1GM1CLC7zh8dZgxNPtCDb0y6kXxM3cZCVRUwLGfS52V D5WUqzMN7IQYgBtexUB8T93P1Vd7bUqjJrt5M9MDf8RZUAu63PPFGZduFX7TGzBheq4K /c2Q== X-Gm-Message-State: AOJu0YyfJg6tiL2/xKMLMbNWqBTdADA2Z//QFfc2KvSf8UI922UbpjUR iPWAAsmHHxKBTLhJ0zD8PNJUO5K/KUj3J/RVWD6R+A== X-Google-Smtp-Source: AGHT+IHpWISn6evOVeDKHwbHWYl5h1d9OmErMjnDnWre/SuX+jMNxEEbDBIPdkoM1XbRgubSJqxhmX2VWp4TRuQSdUM= X-Received: by 2002:a05:622a:282:b0:403:dcd4:b9b1 with SMTP id z2-20020a05622a028200b00403dcd4b9b1mr18232qtw.18.1691688933985; Thu, 10 Aug 2023 10:35:33 -0700 (PDT) MIME-Version: 1.0 References: <20230810103332.3062143-1-ryan.roberts@arm.com> <20230810103332.3062143-4-ryan.roberts@arm.com> In-Reply-To: <20230810103332.3062143-4-ryan.roberts@arm.com> From: Yu Zhao Date: Thu, 10 Aug 2023 11:34:57 -0600 Message-ID: Subject: Re: [PATCH v1 3/4] mm/mmu_gather: Remove encoded_page infrastructure To: Ryan Roberts , Linus Torvalds , Hugh Dickins , Johannes Weiner Cc: Will Deacon , "Aneesh Kumar K.V" , Andrew Morton , Nick Piggin , Peter Zijlstra , Christian Borntraeger , Sven Schnelle , Arnd Bergmann , "Matthew Wilcox (Oracle)" , David Hildenbrand , "Kirill A. Shutemov" , Yin Fengwei , Yang Shi , "Huang, Ying" , Zi Yan , linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: F28E420014 X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: s7xoh3ccpekxkbgp56tofoc5euthdm1s X-HE-Tag: 1691688934-879005 X-HE-Meta: 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 1x8yl5w3 zAGk82i5EU7XU9XzQmIWw1WrZS3t6jSH1rywV8NqsxWDvJodymBSKtoriUj8w4ukDPcDdGFVcRXhu3r0aNkvVsCu4sW+PxIdq8taJSFaHOSTMRZf0wsTqDLTPpnkwdEbVs3NfYFuzVGIG7Ei0dXQt6b01xGUE1xQAa2aLCfKweE23yOaUBfow3dKbcOBfuwrOYie1nsgJVtI/Cej5Qpdfm0PeYSw29GaAYDhEkykZufJRfqcTL+wdIyxBpjHE6J1VTQEiwd8OivVyNwcQJLECvhZZGe3ebJ1UcXJFPTCIOF3O5fob8aBnC3cWNvaNnvy4blHCUT0MeQJ9hu0= 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 Thu, Aug 10, 2023 at 4:33=E2=80=AFAM Ryan Roberts = wrote: > > commit 70fb4fdff582 ("mm: introduce 'encoded' page pointers with > embedded extra bits") and commit 7cc8f9c7146a ("mm: mmu_gather: prepare > to gather encoded page pointers with flags") converted mmu_gather for > dealing with encoded_page, where the bottom 2 bits could encode extra > flags. Only 1 bit was ever used; to flag whether the page should > participate in a delayed rmap removal. > > Now that the mmu_gather batched rmap removal mechanism has been > generalized, all pages participate and therefore the flag is unused. So > let's remove encoded_page to simplify the code. It also gets in the way > of further optimization which will be done in a follow up patch. Adding the original author and reviewers... They might want (need) to take a look at this series.