From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.252 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793945587; b=E+B/iKOD06M42CD7M1q/meKpyyHuQFuz0g0nzBpn99i68/I/KaYiDnzO+qG5L50+4k/x w+FHVmUUdDF8tV7Ke2umJKrAXsTe2yu5+Yno27ruZWZxQudkSHB22t3eVaL24WLG94qfj h3HaMmphqYZmeYrWO6btNOrsweURKKP0E4KNRL5JO6OmVoyqli6XPlh1mYql+6mX5bqo4 +Jo8plcclL3YfWg8hhbSUhkbJYDoga9ta+S7XoORUsF7xM/5jx2qOT3O1exmfg3ROlWy5 06OLpFpelKmaFvk4dixJ7IUyMadFSwqpkxMtt+2Dzz7KkY+Z/K3trQ2M0DZ8dCdTggA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793945587; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:From:In-Reply-To:Content-Type: Content-Transfer-Encoding; bh=UeFRryLaJVqpKuXcRGUVHxdnIHbny7uLg2c6R3dh+AA=; b=xZre7e/km7XZr3nwvCL1ZXZH2YzQDcLmXbHodjD0r4341U4Xpjx6VwJbBYjKnmc9dadA PLBx72H14hDXSFhVWfKzp6mlGXgL8EdzSLhtP94e+cxUGz401roJCHqVNxtHPAKzfJPz6 IyLI0+7G6phmRwq2FaTIJpAQPz25JZ19fsEPb8lfWdT48+9+oSC77zxrPhEslUxCQsDxX BX5uZBdMfiBlG17bu7rf3MtQuxZnBsNdwbz+d4iT6CjRIwEEuYY6530msuSSrJsWG/z7K 24MoyEc0R5oNNDoZErNjskzNujOLhITXMZD5vJ0mfDXagQoNN7kRQmDCy/XiGdctItg== 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=bvPJUts0; arc=none smtp.remote-ip=95.215.58.252 Received: from mta1.migadu.com (out-252.mta1.migadu.com [95.215.58.252]) (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 9394B606A32C for ; Fri, 6 Nov 2026 06:13:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 9394B606A32C 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=bvPJUts0 X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=UtMR0huybFZzo68zuG5r3t/yLCzKnw9Q4ZZ92vgROyE=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793945583; v=1; x=1794550383; b=bvPJUts0NfHUKQVK2bHna3jm1DTJS6OWUm5OJ5OLiijya+d6Vfg8vLaYBXApL2GOXiidk85N dP/RwNh/+nLcYXh2IEvX2bbeESfUaQVPaZ79T7zXLqfJ1a6I9Wp+4Y/yIp8ubSq0waJlyLf55yu jrfU62V+HSgFBkLFlkNckuxA= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id ff19274c30c44807; Fri, 06 Nov 2026 06:13:03 +0000 X-Mizu-Trace-ID: ff19274c30c44807 X-Migadu-Flow: FLOW_OUT Message-ID: Date: Fri, 6 Nov 2026 14:12:56 +0800 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 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 3/4] mm: hugetlb: fix GFP mask propagation to CMA To: "Oscar Salvador (SUSE)" Cc: muchun.song@linux.dev, osalvador@suse.de, david@kernel.org, akpm@linux-foundation.org, azpijr@gmail.com, lance.yang@linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org, Qi Zheng References: <1535887c-6be2-4415-b54e-2008e6e7a35c@linux.dev> From: Qi Zheng In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 11/6/26 1:50 PM, Oscar Salvador (SUSE) wrote: > On Fri, Nov 06, 2026 at 10:43:53AM +0800, Qi Zheng wrote: >> I'd still prefer to keep __GFP_COMP so that >> cma_alloc_frozen_compound() itself guarantees compound allocation, >> without requiring callers to supply the flag. > > Well, but aren't all callers hugetlb? And we already do supply __GFP_COMP there > for evident reasons. > And should that not be the case, and you want to catch someone who went rogue, > I would just place a WARN_ON_ONCE to catch it here, so we know who is not following > the rules. > > Makes sense? Ah, make sense. How about this: diff --git a/mm/cma.c b/mm/cma.c index 876635a56180e..45017ed876f76 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -935,7 +935,8 @@ struct page *cma_alloc_frozen(struct cma *cma, unsigned long count, struct page *cma_alloc_frozen_compound(struct cma *cma, unsigned int order, gfp_t gfp) { - gfp |= __GFP_COMP | __GFP_NOWARN; + if (WARN_ON_ONCE(!(gfp & __GFP_COMP))) + return NULL; return __cma_alloc_frozen(cma, 1 << order, order, gfp); } > >