From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6A3611A8F84; Sat, 15 Nov 2025 01:23:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763169802; cv=none; b=qtsX7xAgw2TOQGUL9IqvulU4PdcnsxDfTMILbWfD9DCPo1rcc1a66ijs/ZdB0nPmnrdCds1xrCkx3R26j8KfDto5bRVS4JX7XuIIsOlaDvMwe576yu62X4+0PlgQHKAX5Z2WLuA9GzFEpLXMP+cWyN0jxISBWUpJ5PgW7KRrRz8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763169802; c=relaxed/simple; bh=EMdA7LgelkVDzq5X2oeGm8KBPNNOdtKtMm09LzMfpWM=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ZhqL9oPPU77W2hgidln9ynzbLuMRix4XWV6HLLJgkQHAAjh9kk6ghw51eLHq7aO+cvVpqbP3lvnWpYKc5EeXrTSC5RJYXNG4MQHZkt5JMYj1XoF/dCwzyt1BEbTAlqFES6jlGXN5MRwvV35+L9WfTFHIf98PYz88MjEtr4ItJ0s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cnmqR+MX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cnmqR+MX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D2E79C4CEFB; Sat, 15 Nov 2025 01:23:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763169802; bh=EMdA7LgelkVDzq5X2oeGm8KBPNNOdtKtMm09LzMfpWM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=cnmqR+MXWNIY93IIWSP5PhZy9V4XdM6Dc+i9FY0vBFDrhSK5jE8iX2DRe+Lue/pJq 6MK4oSSxyA6KlLgW/0m5Q80afT4rMM/AjjjY82icXhJnVwAGIRQhcQbdZp5tw+Lmrx RAlrrdU2XUYrHxZ0T6HpLqvYHxnM6sSsaWcVd6H2cLj7y1L5zgzNUzJQ7H0l75U6RG BZ+H0Wt0NbxG2fpoaIQvMLDKJ5HDrFFaH3sSu36ucYzG149L4lQKqlMZH2BN8mNhbh y841A3LmAnj+v2jGzdh0sPabpuo0KcgpvH9KREtLMXk496/V+w3iuIdZXzsJPA1pJV 7JLrVOnubpMkA== Date: Fri, 14 Nov 2025 17:23:18 -0800 From: Jakub Kicinski To: Byungchul Park Cc: linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kernel_team@skhynix.com, harry.yoo@oracle.com, ast@kernel.org, daniel@iogearbox.net, davem@davemloft.net, hawk@kernel.org, john.fastabend@gmail.com, sdf@fomichev.me, saeedm@nvidia.com, leon@kernel.org, tariqt@nvidia.com, mbloch@nvidia.com, andrew+netdev@lunn.ch, edumazet@google.com, pabeni@redhat.com, akpm@linux-foundation.org, david@redhat.com, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com, horms@kernel.org, jackmanb@google.com, hannes@cmpxchg.org, ziy@nvidia.com, ilias.apalodimas@linaro.org, willy@infradead.org, brauner@kernel.org, kas@kernel.org, yuzhao@google.com, usamaarif642@gmail.com, baolin.wang@linux.alibaba.com, almasrymina@google.com, toke@redhat.com, asml.silence@gmail.com, bpf@vger.kernel.org, linux-rdma@vger.kernel.org, sfr@canb.auug.org.au, dw@davidwei.uk, ap420073@gmail.com, dtatulea@nvidia.com Subject: Re: [RFC mm v5 1/2] page_pool: check nmdesc->pp to see its usage as page pool for net_iov not page-backed Message-ID: <20251114172318.3aafc438@kernel.org> In-Reply-To: <20251112074118.GA31149@system.software.com> References: <20251103075108.26437-1-byungchul@sk.com> <20251103075108.26437-2-byungchul@sk.com> <20251106173320.2f8e683a@kernel.org> <20251107015902.GA3021@system.software.com> <20251106180810.6b06f71a@kernel.org> <20251107044708.GA54407@system.software.com> <20251107174129.62a3f39c@kernel.org> <20251112074118.GA31149@system.software.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 12 Nov 2025 16:41:18 +0900 Byungchul Park wrote: > diff --git a/include/net/netmem.h b/include/net/netmem.h > index 651e2c62d1dd..b42d75ecd411 100644 > --- a/include/net/netmem.h > +++ b/include/net/netmem.h > @@ -114,10 +114,21 @@ struct net_iov { > atomic_long_t pp_ref_count; > }; > }; > + > + unsigned int page_type; > struct net_iov_area *owner; > enum net_iov_type type; type is 4B already in net-next, so you may want to reorder @type with @owner to avoid a hole and increasing the struct size. Other than that LGTM! struct net_iov { union { struct netmem_desc desc; /* 0 48 */ struct { long unsigned int _flags; /* 0 8 */ long unsigned int pp_magic; /* 8 8 */ struct page_pool * pp; /* 16 8 */ long unsigned int _pp_mapping_pad; /* 24 8 */ long unsigned int dma_addr; /* 32 8 */ atomic_long_t pp_ref_count; /* 40 8 */ }; /* 0 48 */ }; /* 0 48 */ struct net_iov_area * owner; /* 48 8 */ enum net_iov_type type; /* 56 4 */ /* size: 64, cachelines: 1, members: 3 */ /* padding: 4 */ };