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 285E9205E0D for ; Thu, 11 Apr 2024 21:14:33 +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=1712870074; cv=none; b=CMjGo+BpLvXwRWoIJ5Y9Sh+vKvT2wAX50k4W7noRSCuRcF7IltkmwV4sm/vyHwIoHWjWTUsoKge18aqSIvQdNgBiwzW/FzHrI86WaryELJDiJgOttqQlaR+o1BL8pEtLEe+hU0uSKzOKK2HKHiXmGeqNj8UQZpedEvLEY1nVKuo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712870074; c=relaxed/simple; bh=LkpCvjNdHx3AdcAwdq7W06nZei3e2TKwfDHNiCSe6gI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=TqPJVWIbaL8Ky742/ZsfBh6y+fAD376fxDyT+7F2yiUa2BOzYjMeYlfRFV4+0k/DZX3JZVdoCZwCyrKDDU4+8bEctWN0TiDVlDdWSTZ8d6Z9kTZeu4J1XJuO8Ryy7i8UF41MBOFg0CSPPEM/K501prTje/U8tebYDW0cDnve29k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=b+lr+qbG; 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="b+lr+qbG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5269EC072AA; Thu, 11 Apr 2024 21:14:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1712870073; bh=LkpCvjNdHx3AdcAwdq7W06nZei3e2TKwfDHNiCSe6gI=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=b+lr+qbGJw5UgEpkRMguaGHYuAhDh2JEOo5lyCxqWs4WcJal/APC80wipe2ipHBpL O6UBYhVwT4vxMPiAJzfZ6IH5UGfLACdJLOTe/e2eIYWccYlFLh+WLTlPujNqiz7PDB pjmt5msmLV8GYm/giXvYd7RXIAkAQXGZmHSkxIgRkWiTgRBFBwheX3+6QsxmZbPVqN +tzw4yMM0qtic4ax6zW/DSwi3qmmwrtjMYgCAQJN4MSgunzZOADNZcWo8Nnsdg/Kcq BXsbbbEaIbzNei6cRQIHmbEZ1VKtjZ+Vi8GL0s+IfDNfQNA+7iTf8yr7B3HpAolXHA j+e/CLctNugqA== Message-ID: <67ed4392-18d2-4cb3-8ed4-df65737f3da6@kernel.org> Date: Thu, 11 Apr 2024 15:14:32 -0600 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net] inet: bring NLM_DONE out to a separate recv() again Content-Language: en-US To: Jakub Kicinski Cc: davem@davemloft.net, netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, Stefano Brivio , Ilya Maximets , donald.hunter@gmail.com References: <20240411180202.399246-1-kuba@kernel.org> <20240411140154.2acd3d0a@kernel.org> From: David Ahern In-Reply-To: <20240411140154.2acd3d0a@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/11/24 3:01 PM, Jakub Kicinski wrote: > On Thu, 11 Apr 2024 13:45:42 -0600 David Ahern wrote: >>> + /* Don't let NLM_DONE coalesce into a message, even if it could. >>> + * Some user space expects NLM_DONE in a separate recv(). >> >> that's unfortunate > > Do you have an opinion on the sysfs/opt-in question? Not a performance critical path, so I would not add it right now. > Feels to me like there shouldn't be that much user space doing raw > netlink, without a library. Old crufty code usually does ioctls, right? > So maybe we can periodically reintroduce this bug to shake out all > the bad apps? :D :-) On the one hand, yea, push apps to improve. On the other, Donald (FRR) is one who complains about nightmares chasing nuances across kernels.