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 627EFC5B543 for ; Thu, 29 May 2025 11:54:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CB0546B0151; Thu, 29 May 2025 07:54:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C8C856B0152; Thu, 29 May 2025 07:54:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B9E846B0153; Thu, 29 May 2025 07:54:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 9BB2C6B0151 for ; Thu, 29 May 2025 07:54:43 -0400 (EDT) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 39D731401BF for ; Thu, 29 May 2025 11:54:43 +0000 (UTC) X-FDA: 83495788446.06.E0ADFEE Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by imf29.hostedemail.com (Postfix) with ESMTP id 6048612000C for ; Thu, 29 May 2025 11:54:41 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf29.hostedemail.com: domain of jonathan.cameron@huawei.com designates 185.176.79.56 as permitted sender) smtp.mailfrom=jonathan.cameron@huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1748519681; 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; bh=sGJqQfkYCDfpnMYyulUs/vbd895i5EGhHIPwf7Mhkcs=; b=i/0wStgTqglChWx+RLMfhwxXEtjA9dc7NwfQwBpGV6Sq2GJI6leuVL9W7Gr/gglzw1rrfv ed17riGUbgESiCbCPlJnVxB/PxGmAr4lVR39tK74IiMzllU/+NNNlzTnKfxDmsn/D6NWhT Szr0KvnQ8uE2zGsTV0WD5CVHgk/DHGk= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf29.hostedemail.com: domain of jonathan.cameron@huawei.com designates 185.176.79.56 as permitted sender) smtp.mailfrom=jonathan.cameron@huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1748519681; a=rsa-sha256; cv=none; b=vO7oeAJXC0Yw/TpjvYLgJR8kAsSjL2XvLNryfxCIuMoy/EDBOWbQz6VGbKHjyJZqvtSxMU CJsU241K6Vy19JstYrHUlNxvwfi3Wezs8xd8PzRANjFnzRrFYDIohSJj3RYo2GJCiTFyjA gGPMaPKoms/5LX8E2ZgX2vGPDAsZLkI= Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4b7PpG0pPHz6L5j3; Thu, 29 May 2025 19:51:02 +0800 (CST) Received: from frapeml500008.china.huawei.com (unknown [7.182.85.71]) by mail.maildlp.com (Postfix) with ESMTPS id A1AA5140519; Thu, 29 May 2025 19:54:38 +0800 (CST) Received: from localhost (10.203.177.66) by frapeml500008.china.huawei.com (7.182.85.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Thu, 29 May 2025 13:54:37 +0200 Date: Thu, 29 May 2025 12:54:35 +0100 From: Jonathan Cameron To: Alistair Popple CC: , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH 07/12] mm: Remove redundant pXd_devmap calls Message-ID: <20250529125435.00001378@huawei.com> In-Reply-To: <2ee5a64581d2c78445e5c4180d7eceed085825ca.1748500293.git-series.apopple@nvidia.com> References: <2ee5a64581d2c78445e5c4180d7eceed085825ca.1748500293.git-series.apopple@nvidia.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.203.177.66] X-ClientProxiedBy: lhrpeml100004.china.huawei.com (7.191.162.219) To frapeml500008.china.huawei.com (7.182.85.71) X-Rspamd-Queue-Id: 6048612000C X-Stat-Signature: awf1ssajg8zuxs83q34a4a9bwd9qteo7 X-Rspam-User: X-Rspamd-Server: rspam07 X-HE-Tag: 1748519681-896208 X-HE-Meta: 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 08RnJEdh T6HU7WnZqYpfn18q5AhxGbKoCbYbmmHveqOLepgeFSfEDGk1nRQyAAcXVdd+oMDly9Aw8EUKVUWNkbMYPnxxKWjF+6qH4vxsz2PR5UTgquEzA8kw0ul4iO6NNj2FjMdgpBQmhjrKXScpLVeNSpdTFaRyqES3lTXKs//pFZcDyj13ad2xeUGXWzcvZvxsUe3dUXYTL24gJbqf5FBxizDvHef7hTbR2Mmv5owgv30e05oiPYYdKyiB5+aCK0rKzUEmlj1+IZwCfXB89KoPQd5vxqOG1591JFf8R3bfMGEts8Y2p4EXZdbtJRPKweqcriDXCgIlgpD3ivQ5DEA3BmxAhxyVstmpA0cdn3Htf/NSTIvhZ/PM= 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: On Thu, 29 May 2025 16:32:08 +1000 Alistair Popple wrote: > DAX was the only thing that created pmd_devmap and pud_devmap entries > however it no longer does as DAX pages are now refcounted normally and > pXd_trans_huge() returns true for those. Therefore checking both pXd_devmap > and pXd_trans_huge() is redundant and the former can be removed without > changing behaviour as it will always be false. > > Signed-off-by: Alistair Popple > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 8d9d706..31b4110 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -1398,10 +1398,7 @@ static int insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, > } > > entry = pmd_mkhuge(pfn_t_pmd(pfn, prot)); > - if (pfn_t_devmap(pfn)) Didn't this go away in patch 5? I didn't check but this looks like a bisectability issue. > - entry = pmd_mkdevmap(entry); > - else > - entry = pmd_mkspecial(entry); > + entry = pmd_mkspecial(entry); > if (write) { > entry = pmd_mkyoung(pmd_mkdirty(entry)); > entry = maybe_pmd_mkwrite(entry, vma);