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=1793811011; b=kqYpgKMHq011lIckRUD2E5+equn8Q3Y6ivTI5wI2UZHIPwRZeZLX+OZ9wHMFEWLPva90 An18RIag2dlUfbofmERA9QOR8jhcyqrSPPhdzPvqizZR6MGBSdclpcR82gYoc4YklGTo0 RztGT0Alw+4Vtc94W8B9S/kXqn3OTCp7s5IxaWHZ1ZM/K9/Z1RwSRafexf4nGzxtX48Lx mKwZSvSWJj2UiGApjwKVnh7sMsYSGv5vyYT9PYJxiA/XUcbokVtIvqHCd5JM30mGZTD9R OVRi1x2XFQfz65e6Ap6GhGI8IOtCmom3xOtL95fUzb1PT4HbaeMjxgUG9A+nEryLChA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793811011; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=h9wu6kihgi9yB1xWkuSesGFotgBTDc+RlqCdPr5bB/c=; b=CSRnkPzrhmlbKVG6Pi9NAjUJHmfHQZzrAFPjjkfushHarvNN4w5pZ/v9FbuaBOeovd+V mZUFievqWQBz5Qe+BpTJ2NF1yZPyVMCbHxhpzOSeifwuFv6xIEm+W7XkeybYkRmZ0hA5g N1uljyfbVlTr7nXekylq3Qel0ME2dfbpPl/aT7HXSL6BoKQuF1O2B9Qekob91oSfCI4Ph /amDIkeyeI2vprC0gS/wxDxYUPAtt7y6ZBJpRrucQpwtI76dLhHYbhpIhZXXwPxCM8tMJ GniKDyYh4cI/7ODvi/AUSm8uYfYUN/TQNFWi9lT6JKVuVCphu5TDwemnX+SGGIvQb1A== 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=bKWIpJro; 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 21505606A31B for ; Wed, 4 Nov 2026 16:50:10 +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=bKWIpJro Received: by smtp.kernel.org (Postfix) with ESMTPSA id CDCD41F00A1F; Wed, 4 Nov 2026 16:50:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793811010; bh=h9wu6kihgi9yB1xWkuSesGFotgBTDc+RlqCdPr5bB/c=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=bKWIpJroWZmQuSMKmkcHkS+KBMrgb1w1jTz5HKzXIOr50CEf78uf0IDuq69Df3xiG McCrtoOIvk0xb6p6wbnwjGvzKd6b6pyVQf4nKgBFJap0yATUxKBBuOYv3hAxPCo9+z 5piNj6JnHodsMU9py/wzB+LPq7CLnzXj5WQz0Bj42hex+bec+bW9zqWjC7hrHRS2IJ tlvXHJC7RxLi3+LmQyX6yRcwvcx28ds5CuCBBa4/hScO7VelF15BopQikaxNJn608s 0vUMHKv70OmXy28yj7eKHQK9jOI7XNRssHsj8OdrzqaI+XX28zWZTY9aH9cN7yI7GJ 05o1Esz3NWV3w== Date: Wed, 4 Nov 2026 18:50:04 +0200 From: Mike Rapoport To: Pasha Tatashin Cc: Pratyush Yadav , Alexander Graf , Andrew Morton , Chen Pei , George Guo , Kexin Liu , Sourabh Jain , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 1/2] kho: skip zero-sized lowmem and global bootmem areas Message-ID: References: <20261103-kho-bootmem-sizing-v1-0-45aa74098f34@kernel.org> <20261103-kho-bootmem-sizing-v1-1-45aa74098f34@kernel.org> 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: On Wed, Nov 04, 2026 at 10:32:14AM -0500, Pasha Tatashin wrote: > On 11-04 13:22, Mike Rapoport wrote: > > On Tue, Nov 03, 2026 at 02:48:36PM -0500, Pasha Tatashin wrote: > > > > @@ -852,56 +873,32 @@ static void __init kho_reserve_bootmem(void) > > > > * reserve bootmem area in low memory for lowmem allocations in the > > > > * next kernel > > > > */ > > > > - size = bootmem_size_lowmem; > > > > - addr = memblock_phys_alloc_range(size, BOOTMEM_ALIGNMENT_BYTES, 0, > > > > - ARCH_LOW_ADDRESS_LIMIT); > > > > - if (!addr) { > > > > + if (kho_reserve_bootmem_area(&i, bootmem_size_lowmem, > > > > + ARCH_LOW_ADDRESS_LIMIT, NUMA_NO_NODE)) { > > > > pr_err("Failed to reserve lowmem bootmem\n"); > > > > > > You are adding a helper that returns an error code and then ignoring it > > > at all call sites. Even though it can only return -ENOMEM right now, > > > dropping the return value is not good practice. > > > > I don't think error code is important here. > > Perhaps, but it is just not elegant to add a function that returns an > error, call that function from three places, and ignore that error every > time. Because it's not important what the error was. > What is wrong with: > > err = kho_reserve_bootmem_area(...); > if (err) { > pr_err("Failed to reserve lowmem bootmem: %pe\n", ERR_PTR(err)); > ... > } More churn for no value? > -- > Pasha -- Sincerely yours, Mike.