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 E219C182A51; Tue, 9 Jul 2024 18:11:34 +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=1720548695; cv=none; b=PUNGZykvMH86EN5exhaa0E3Llr7s3Ha3S1Wu3aucruWZknWrv7HIcz2lA3Kqu7cl2S6sgdNDp8dcVTYMgza3F5n9qoUlkMFqQ9kkuOI1tB68Wag1t0LhEGGhkzDLhnMewjBkBwYAi7yy3BZP6C4857n9BF+vTpoLtYsOrh1M2DU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720548695; c=relaxed/simple; bh=vmKXIZftIMmUvIjQn6H9m8+/Z4ol58D0xRGXk1f2Epw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=S4B5EIvuK4wSIeQvieXeS39S6jqNK7D7b4ujzo6iX6am4jiGEVkq8BwRXlxOok9jKf9hiBCyw78YucPT/TIy9xYDYhZ16BCJoGEwuqGPI0C0RyGI5jnkNAt5AOuWtgORws7jykTBjMxU29koeXU90/2XyUldDJEgdQfWGvGAs1E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=vRCufdPb; 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="vRCufdPb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AA0F3C32782; Tue, 9 Jul 2024 18:11:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720548694; bh=vmKXIZftIMmUvIjQn6H9m8+/Z4ol58D0xRGXk1f2Epw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=vRCufdPbcmGi6dtPoZXTY6MDS2cU/kITaI815vaF+sAxC7EnvMf5Kj30Bjin4x6Wc Ec2kPiJEump+XPpCPdLSYQEN7AAdrYbZ1PnDgH4Q5PRfi8aRbc9ewKMyCJMsT51Jh4 BOZoGsU3jFL5lIWY6w3vY8QMWMaLYzi280XT4W/PEEY85Whb3tFzUFoHC7oEl4epQ8 7nsInslcd25Gb24INbrOI04QbQEfl2Dtz3zZFtXu1vF+SZrRcrup1yQ9/k/tdAYafv z3PrgTJDGZp73cPJmERZZiDU9G6VQbxarjw843+LJR6v1ry4tnAX1XHapomSwWQA/c uhAoE2OXI2QuQ== Date: Tue, 9 Jul 2024 19:11:28 +0100 From: Simon Horman To: Breno Leitao Cc: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Kees Cook , "Gustavo A. R. Silva" , keescook@chromium.org, nex.sw.ncis.osdt.itp.upstreaming@intel.com, linux-hardening@vger.kernel.org, Alexander Lobakin , Przemek Kitszel , Jiri Pirko , Sebastian Andrzej Siewior , Daniel Borkmann , Lorenzo Bianconi , Johannes Berg , Heiner Kallweit , "open list:NETWORKING [GENERAL]" , open list Subject: Re: [PATCH net-next v2] netdevice: define and allocate &net_device _properly_ Message-ID: <20240709181128.GO346094@kernel.org> References: <20240709125433.4026177-1-leitao@debian.org> 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-Disposition: inline In-Reply-To: <20240709125433.4026177-1-leitao@debian.org> On Tue, Jul 09, 2024 at 05:54:25AM -0700, Breno Leitao wrote: > From: Alexander Lobakin > > In fact, this structure contains a flexible array at the end, but > historically its size, alignment etc., is calculated manually. > There are several instances of the structure embedded into other > structures, but also there's ongoing effort to remove them and we > could in the meantime declare &net_device properly. > Declare the array explicitly, use struct_size() and store the array > size inside the structure, so that __counted_by() can be applied. > Don't use PTR_ALIGN(), as SLUB itself tries its best to ensure the > allocated buffer is aligned to what the user expects. > Also, change its alignment from %NETDEV_ALIGN to the cacheline size > as per several suggestions on the netdev ML. > > bloat-o-meter for vmlinux: > > free_netdev 445 440 -5 > netdev_freemem 24 - -24 > alloc_netdev_mqs 1481 1450 -31 > > On x86_64 with several NICs of different vendors, I was never able to > get a &net_device pointer not aligned to the cacheline size after the > change. > > Signed-off-by: Alexander Lobakin > Signed-off-by: Breno Leitao > Reviewed-by: Przemek Kitszel Hi Breno, Some kernel doc warnings from my side. Flagged by: kernel-doc -none > --- > Changelog: > > v2: > * Rebased Alexander's patch on top of f750dfe825b90 ("ethtool: provide > customized dim profile management"). > * Removed the ALIGN() of SMP_CACHE_BYTES for sizeof_priv. > > v1: > * https://lore.kernel.org/netdev/90fd7cd7-72dc-4df6-88ec-fbc8b64735ad@intel.com > > include/linux/netdevice.h | 12 +++++++----- > net/core/dev.c | 30 ++++++------------------------ > net/core/net-sysfs.c | 2 +- > 3 files changed, 14 insertions(+), 30 deletions(-) > > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h > index 93558645c6d0..f0dd499244d4 100644 > --- a/include/linux/netdevice.h > +++ b/include/linux/netdevice.h > @@ -2199,10 +2199,10 @@ struct net_device { > unsigned short neigh_priv_len; > unsigned short dev_id; > unsigned short dev_port; > - unsigned short padded; padded should also be removed from the Kernel doc for this structure. > + int irq; > + u32 priv_len; And irq and priv_len should be added to the Kernel doc for this structure. > > spinlock_t addr_list_lock; > - int irq; > > struct netdev_hw_addr_list uc; > struct netdev_hw_addr_list mc; ...