From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793203734; b=pRcmwQSCcgkRt7rbppGgRxP2xfhyQm+SbOywiIxrzW38NER+YDyKKZPF4xKdg/dWxNpX hB/qu0laI3Rh1vt236Bho+XYxA0AtaJSuegITVSNrwfDHWZpdMz+/o7SUxazKwa/rCYwN OQkHJ1DmN1llUg44untoaw58ljsjez0da8Qbo/RMENl8g5y+lSUVrAa9+OLmP7QOxJq2W zIelPBWs+pYVu5dZQNClqtqLQToiGMZ4DydT00A4Dir0p0YqgHCnO88M5ctD5413Eprih ab0FV0Fevo8jN/0OpG70f1S7uzWKb9+UUAnEfsf8B3Zqf+ylR5eZXutosuVlerndovQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793203734; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=8vo1r+wQbOzLzCV+CAr1Yh9jJ1GiuCBkoMlOOYp8Wt4=; b=rf5seK1yQroDvpJENV3BfP9i7efDkqy/TU+jZ+rJA1KaHfS2ic4UwL5S+LC8Fo9eV1ox NHZYgTivvGi+D4k8KxZKYLbj+OIlJ0j2KMKcPg4S865XRpOvQRGbw5euy5CEsuL6Lhx7i Rs3XkCrKwKEA0ppvvhK2PuDQKzQqQEZoa2QKvda+0M2dyKcbZ/jM175pPVQZ2igiDaHz+ yEXQFx77YGSFKQ2BDStdZU5XKu9oa8C0o7q+Jcu+qfGu09TEDy/g0t0bbtt4CmM0Ixt0v zAhhp1kcWHZAUkUWw8BtVP07w+ZkJOcYjYs4J3bIlatgUQIyMg2pnp3SOWigsFN/aRA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=VVZwcwyV; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D3D9D606A32E for ; Wed, 28 Oct 2026 16:08:53 +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 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-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 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261028121129.39916-1-kaitao.cheng@linux.dev> 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.