From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.193 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793192761; b=HMWOqnl2GXkju5KhBsZ7Zs2rRO3AcVavIaLqf0AueqUlVK3Wdzk/lFdar6pUoz+x9N4Q LWDCBzR4PdHSxwqBglfdRJMqawuy3B937q+dMglsm0piXViHAaNKwGsQLgbQQ9JKPw6EP YP2rqPsGAFAqILZyC02K8FM0w/u9eI8P3y0MR23lHZ7Ud1KvwCK38NKrZmFcPPppRRSaI uW0/Pb54HfoT72OLZslnfL6BoczgEss80SBadbJjt4HHk/TDlkbfuTfET0ZtLkPuXbh+W LRZgk9tdh4FpJBM1tIFvxiQROFWvxVUxsrOCo+vfoOPpODF9rEDlmGIebPEfJY8KBpQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793192761; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Content-Type:Mime-Version:Subject:From: In-Reply-To:Date:Cc:Content-Transfer-Encoding:Message-Id:References: To:X-Mailer; bh=zQ37RfglzdINqejwc5JbxUwWcf6fyXiPnEVqkiyj9wE=; b=WG3620XhC4JcPRZZflwye2zT1Wj+1ahGYIreoMo01fDQD/DaKkcbSPXlTu5bLO6cW7sZ BNdCtOCUrQ27wyNDzyHFJpx/BeNt+SfFA6Hy7Bc1Lb5sm90kfTUHrHbVqos9mCOfN26/N jJiV4k2n4l+lP3fvuzAudGPbwn404aV2Wlwq7SSGxi/4g2JleZC3fP89tFsAiTeQcj8ph bEKRL44xdfUjLPBLCNU7LmWZxee3of1yiM2TW3teQhONgjHR408otY+F5q72gyqJJjMjM EEL2qqITnq6IxqC0YULo8gG8gw2FMpo9HEc5JafUTYPg2y8MrFoh0D6AhmlQ64ecrhw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=l+qjavsJ; arc=none smtp.remote-ip=91.218.175.193 Received: from mta0.migadu.com (out-193.mta0.migadu.com [91.218.175.193]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9D331606A31C for ; Wed, 28 Oct 2026 13:05:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 9D331606A31C Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=l+qjavsJ X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=8ZJqLauaB75tCQkdQ/iL1btTWlyXZvR89RMo3Rbmqm0=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793192757; v=1; x=1793797557; b=l+qjavsJub2Qwlt0kiwwZUKHqTD07Hrdeuj+5NMf5+2n5KY9kWiqdYvKqjB1Y8y/Qf4wAPYS jKTevQ5+bxWUgn5piUbQllcX7GvwLshacXL4NgQuibsfSwaaceXRoyKQ+9gtP3IvW1gDjcTJVtE pUGFwBfMZyDVBNIdj9tza0n4= X-Envelope-To: linux-kernel@vger.kernel.org Received: by mta12.migadu.com with ESMTPS id 70cb52b1da55fe0c; Wed, 28 Oct 2026 13:05:57 +0000 X-Mizu-Trace-ID: 70cb52b1da55fe0c X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset=utf-8 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3901.100.1.1.12\)) Subject: Re: [PATCH] mm/sparse: simplify the vmemmap alignment check From: Muchun Song In-Reply-To: <20261028121129.39916-1-kaitao.cheng@linux.dev> Date: Wed, 28 Oct 2026 21:05:40 +0800 Cc: Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Kaitao Cheng Content-Transfer-Encoding: quoted-printable Message-Id: <66E340E5-B2D2-4DB9-AE01-4F98C3182B06@linux.dev> References: <20261028121129.39916-1-kaitao.cheng@linux.dev> To: Kaitao Cheng X-Mailer: Apple Mail (2.3901.100.1.1.12) > On Oct 28, 2026, at 20:11, Kaitao Cheng = wrote: >=20 > From: Kaitao Cheng >=20 > 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. Yes. >=20 > Use VM_WARN_ON() and fold compound_info_has_mask() into its condition, > preserving short-circuit evaluation. >=20 > Signed-off-by: Kaitao Cheng > --- > mm/sparse.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) >=20 > 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( We usually don't end with "(=E2=80=9C. At least I rarely see that in the = existing code. We can break the line after &&. Thanks, Muchun > + (unsigned long)pfn_to_page(0), = MAX_FOLIO_VMEMMAP_ALIGN)); >=20 > sparse_metadata_init(); > sparse_init_subsection_map(); > --=20 > 2.53.0 >=20