From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3E064606A324 for ; Wed, 28 Oct 2026 16:08:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=VVZwcwyV Received: by kanga.kvack.org (Postfix) id 510DA6B05B0; Wed, 28 Oct 2026 12:08:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4C1C06B05B1; Wed, 28 Oct 2026 12:08:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3D7706B05B2; Wed, 28 Oct 2026 12:08:57 -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 16F786B05B0 for ; Wed, 28 Oct 2026 12:08:57 -0400 (EDT) Received: from smtpin30.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 5FC1B80154 for ; Wed, 28 Oct 2026 16:08:56 +0000 (UTC) X-FDA: 85372518672.30.81B9BC3 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf17.hostedemail.com (Postfix) with ESMTP id 9F9044000A for ; Wed, 28 Oct 2026 16:08:54 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=VVZwcwyV; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf17.hostedemail.com: domain of rppt@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1793203734; 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=8vo1r+wQbOzLzCV+CAr1Yh9jJ1GiuCBkoMlOOYp8Wt4=; b=Yi4fBLJdsEuHyVYg1XGaVqZWJulivq+rhQ9F8yJCMf6SgyrpPbOZ22lLtwxRel5uIcghod jHZJHwruBAxXj3XmrMCVlyt9dPfSOZ1HSZZCv4lImsAq2Iz5wtCnCYSaeowUAPQwLvqxO8 H+dWBi4TLEZaTkpkcbyf63K9y/1N9KQ= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=VVZwcwyV; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf17.hostedemail.com: domain of rppt@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=rppt@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1793203734; b=Y2iUPuiTNT2DQ4wpeu4rK0DRAkdjnXsy0Ovt49G1zYId5JP1o9rcxvNiFcCD/WT1ksodpb y8Zv/NQW9HD08V1/ZCg5LF2Hk6iDdMGg4z0MgCFevlTVFlTiimoyhJVhQ+K+Oj/iOqpyJ8 wy6JmldLgL2L619P+vDexeQdgTN2C+8= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id CD70443BDF; Wed, 28 Oct 2026 16:08:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DB8711F01301; Wed, 28 Oct 2026 16:08:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793203733; bh=8vo1r+wQbOzLzCV+CAr1Yh9jJ1GiuCBkoMlOOYp8Wt4=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=VVZwcwyVvSGy32C+lIKbS30eALeGvBJZe+g4bcBdMztrsf6jMbOXEq8QfsnHf6XsN ZaYNXTWdnRcvpsl5OoIe1oIb8MyPAhJPCGdcR5u73Cy76hqzvj9H76jSUKwkbxpEV/ agYoy6aZXGkzxcOo4xEF5c47SnvYEXeM1bD1gRrlzKC3kIGzqwwxIgNrAuPA6TY8Jo /vm80F2+VKdZkXF+LTNezNOC0eRYYCXwxq1On7B4ooG8w/c3qHo7K8vYWYrealIc6E WkxCdcMc84FLf9C029GNywxwIMZ6vhKpxVMIUYXbILBccEptSNycsEZG+z0U8K1Dvk kdO5rYESs50hg== Date: Wed, 28 Oct 2026 18:08:46 +0200 From: Mike Rapoport To: Kaitao Cheng Cc: Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , Muchun Song , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Kaitao Cheng Subject: Re: [PATCH] mm/sparse: simplify the vmemmap alignment check Message-ID: References: <20261028121129.39916-1-kaitao.cheng@linux.dev> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261028121129.39916-1-kaitao.cheng@linux.dev> X-Rspamd-Queue-Id: 9F9044000A X-Rspam-User: X-Stat-Signature: cwewqjusjfj9guec4nc9e6xijseqg633 X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Rspamd-Server: rspam03 X-HE-Tag: 1793203734-675240 X-HE-Meta: U2FsdGVkX1/1qw3IXUO4BKbFWwpv57PZTCEetST5hOo8dzSVwQDqtvDgxpmj1n06zDcMINZTCYyVc173QqkJWfd46Lols4lQQGJquYK1QFDUJNIMAXFbrmceNMo2emDpImWhDVE9+I4M+xR60D4mx7gnrTUDY/QrmTzCoBVBc7WUBsKSox8YyS47lWmrx9msj8j0sxKxtKemIpljwktxLF+IUUz816h3DnC3xjh/GtbJH80DQKkZbvTUE871FTgqRnMs4RUL0D61201pdqPUvSVF7YBpfIP8rjNjR2LWWZth1CdR//3wNI0Yrtalk0h0rIEwqAylxS3mwAdlnBWS1VMFBUHFChURdqMONMNdrx7u8ALxeXa5dfTLVwjmHTm8W14WRWn34GfzyJ2clg0OILRynbQdvsDoe9I7nQvvGwwaXyM8hYGpSn5Q/8XOBLh/NQcDbrseD400f05eRG9If87DKw/rG1ycBDDNJM9i1l0bDXamzYwrrgjlfFH/lLXlvP6MOio6kjZfWb1dxbh7k1NuYX/vbcywsXtDjwyv3XVGG3E7dOEzF/3bLcWNwCny1vGSnECw2utrOj2BGugdd7mMjq9zEyF32mk/5lwpTzjNGuWvkG0+XTaAbaECMp19FSSlxNgfKh2bhddzpK17eW7ZFDl0l3CwOpYqm0vWDtmbzkAB6fvvv7zw4jEkv3KgtE9e9fHE4sco0haszEzwNyKrV7Ot4PYTQ5Ln4JFx6CYrlQ294dHNPylJhMkqeucFe2TwlXEapobVWKTP0UF5vPS1PWW6ngYz2Vj/tL2eFDZRfD8cyJNt71gLADTzNSLr+/50TrF8Z8ZnKCDK3CBufW8Mn9VijESuglQGEGFSHioVUNIApOpKJlZSaiDU+HuFI/nbCOWH8Szd8BPDZoF0FgYuulsoLzT2nLaLVztxSXf3bt3X02FVsv8MypNrsyGtRMR3ZpMaBTLjRehEvNI Q6oXIEvn Dw9YgR0oP5aTjkJqHngwLHMswNvZ+XR0pwzlWpJI58pSP6zlZ0uwdXlvwuaukvyXC6lK86mTE1EiHVQowm/4oXvbA/a/RAIM+3/fC1OvkwwsasXbEUD+nBKP3gPPIi4MXiaC92qxQ1w4NOMBwvFySKjjC36LD+MtwxYVvtBRjQ8voWjLRDUXmIkeJV9TZ3Chm79rnbyGWIbm1FpjjTJpYeHpUVka0On2LXipsVko4AQfVktQNcRisTAjSVR+J/g8ZHlGq Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 Hi, On Wed, Oct 28, 2026 at 08:11:29PM +0800, Kaitao Cheng wrote: > From: Kaitao Cheng > > sparse_init() is called only once during boot, and the vmemmap alignment > check is outside any loop, so VM_WARN_ON_ONCE() provides no benefit over > VM_WARN_ON() here. > > Use VM_WARN_ON() and fold compound_info_has_mask() into its condition, > preserving short-circuit evaluation. Do you think it's worth the churn? > Signed-off-by: Kaitao Cheng > --- > mm/sparse.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/mm/sparse.c b/mm/sparse.c > index 6acb628c8a73..248bee2d39b9 100644 > --- a/mm/sparse.c > +++ b/mm/sparse.c > @@ -277,10 +277,8 @@ static void __init sparse_metadata_init(void) > */ > void __init sparse_init(void) > { > - if (compound_info_has_mask()) { > - VM_WARN_ON_ONCE(!IS_ALIGNED((unsigned long) pfn_to_page(0), > - MAX_FOLIO_VMEMMAP_ALIGN)); > - } > + VM_WARN_ON(compound_info_has_mask() && !IS_ALIGNED( > + (unsigned long)pfn_to_page(0), MAX_FOLIO_VMEMMAP_ALIGN)); > > sparse_metadata_init(); > sparse_init_subsection_map(); > -- > 2.53.0 > -- Sincerely yours, Mike.