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 D04E431D372; Thu, 16 Apr 2026 15:31:53 +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=1776353513; cv=none; b=pUrbQPVrNMSq0DRTXsNoO9ojmJG1WWPVGP030yYAPuqOposg8iIYyZAAJi4y3TXxEZxMBtvVuaotysQN3AlwfRsI1hZiO1W5p2uhqEEpAu7dz8AbOmO6G2b0/u/QE8vw54SPdkEdGH+WFoihNFi4wX15kja1BBhxnPT7l+OtLcg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776353513; c=relaxed/simple; bh=jssH9UnmqcByLPfuDr/larPx0BO5IHoq0niW0tXf3+M=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Y5wazEPCbZqc2k1QS2aDSmg5gBki2ecGV820MSlqhV7sYguEREIPevT9VewpgAr9Nc+bgxKnK9GMAEOjDKoM+bxog+5tO/Ky3pD1eouDEL1SafmwnkH4oIIuuJFVZDLMP/Akj8r3fH0mewR3Z/qvJXmEmMrR6i749+wDdkOKdRQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rJeQKmWH; 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="rJeQKmWH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 42F8FC2BCAF; Thu, 16 Apr 2026 15:31:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776353513; bh=jssH9UnmqcByLPfuDr/larPx0BO5IHoq0niW0tXf3+M=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=rJeQKmWH9lDUzBvTjARIDU98AO0+auPSAoka02Vtd1q2HWyFeHjfPxrliSbxxkM1b RTKMoYRGIOENlqhwZEfa0zuUiHFOyu5bWVFvVHDRYd40Rg/cotfqdg3HDtOOWzuv/J FndVfnAcgyJ5yBjbW8QLsf4JJ4CfMNahcsWg0d6wYpnJbOEgq+du9T0bHoWjx9eDMi AkgTiJ1Lnn3cArm8BA1E2d1LFPBhTnko5yW/56Q2Spx8My+14LjXoMYeQ7qBaNXPb6 MrQ6EN4LludV/tbqrwNcmTY8tyRoyltnryGLp70Nch/VjCpf8E1/ZZ1vEQmE0XehmR MGoi9BpIGfCiA== Date: Thu, 16 Apr 2026 08:31:46 -0700 From: Jakub Kicinski To: Dipayaan Roy Cc: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, leon@kernel.org, longli@microsoft.com, kotaranov@microsoft.com, horms@kernel.org, shradhagupta@linux.microsoft.com, ssengar@linux.microsoft.com, ernis@linux.microsoft.com, shirazsaleem@microsoft.com, linux-hyperv@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, stephen@networkplumber.org, jacob.e.keller@intel.com, leitao@debian.org, kees@kernel.org, john.fastabend@gmail.com, hawk@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, ast@kernel.org, sdf@fomichev.me, dipayanroy@microsoft.com Subject: Re: [PATCH net-next v6 0/2] net: mana: add ethtool private flag for full-page RX buffers Message-ID: <20260416083146.0bb94d2b@kernel.org> In-Reply-To: References: <20260407200216.272659-1-dipayanroy@linux.microsoft.com> <20260409183509.0b24dea6@kernel.org> <20260412125917.4fa8fc8d@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@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 Tue, 14 Apr 2026 09:00:56 -0700 Dipayaan Roy wrote: > I still see roughly a 5% overhead from the atomic refcount operation > itself, but on that platform there is no throughput drop when using > page fragments versus full-page mode. That seems to contradict your claim that it's a problem with a specific platform.. Since we're in the merge window I asked David Wei to try to experiment with disabling page fragmentation on the ARM64 platforms we have at Meta. If it repros we should use the generic rx-buf-len ringparam because more NICs may want to implement this strategy.