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 C2AF71885A8 for ; Wed, 11 Sep 2024 22:25:40 +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=1726093540; cv=none; b=Al0APWasL9fSlaejuLWlZGRu3mbIqnZ5ShRGEUXIe5FjNtG0eqlP5ePbR0ifjx9bsSk7Jh24cZGiKXJXyfffSvcPV2b1Q07i3psz9J4+EYOJyU77MBxpj/3Yv8SBASNHSDYXBdXPn5pde1QJ238QaadO1Mr+zyczsTGOSiioW3c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726093540; c=relaxed/simple; bh=MH7eVIICBehm6rrwRo1VomRmFryYT0oORsOlNKawq5o=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=K5LDtjS6EhXm9Av7ZHyhC6QzbL24sYezt6Lt4IItE1/ND/fwluTpYSYTWBFTZiyqgeZoJeb27EhKK5gq11/ZCPy5oJoJRD0OATBKCe7SaBioB27iyxz52ZJyrggzslY0Yhu6RvnW3Ldy7VjnizMuUnAwuVKqMtzTvSxpEYyDZGI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=p/QY/Pzg; 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="p/QY/Pzg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9FABC4CEC0; Wed, 11 Sep 2024 22:25:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1726093540; bh=MH7eVIICBehm6rrwRo1VomRmFryYT0oORsOlNKawq5o=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=p/QY/PzgJZNPDLtBH54nlbjb/yxWpKH6USSDIxavN7adUg+1vB1/NL5RrQi3PhJYc H7p8PD1amP6w8NvbQmLucwNw7s8fXA1cfj3dz5exRszDUd9+ngCBbQqbrzwsER0v1n JoF95/wjF5HbJ4wOJ8zsYPPbs6Ic77JvneNK992IGq35nzpbtH34zesk/4oD0Zfdgq 4gGAslE5U/zPjzAJBLgh4Z1lVR7DRAv8e8mVbe0y5Sn8+YGepAloKlOt5pcysPKkU9 KWGA3v4mUl0tADrXXb2jIe3FIL83Vd+qw/1A33LZsYWPTmrzVl4oNCRBnvuJO+izgh tBoIahUApxWyA== Date: Wed, 11 Sep 2024 15:25:39 -0700 From: Jakub Kicinski To: Andrew Lunn Cc: Vadim Fedorenko , David Ahern , Paolo Abeni , "David S. Miller" , Alexander Duyck , netdev@vger.kernel.org Subject: Re: [PATCH net-next 2/5] eth: fbnic: add initial PHC support Message-ID: <20240911152539.4030764b@kernel.org> In-Reply-To: <4c720c2e-7a60-4f94-96bd-94ab59fa8905@lunn.ch> References: <20240911124513.2691688-1-vadfed@meta.com> <20240911124513.2691688-3-vadfed@meta.com> <006042c0-e1d5-4fbc-aa7f-94a74cfbef0e@lunn.ch> <20240911131035.74c5e8f9@kernel.org> <4c720c2e-7a60-4f94-96bd-94ab59fa8905@lunn.ch> 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, 11 Sep 2024 22:45:11 +0200 Andrew Lunn wrote: > > > That's good question. Do we need another set of helpers just because of > > > names? Obviously, the internals will be the same sequence magic. > > > > Good question. To be clear we want a seq lock that goes away on 64b > > since what it protects is accessed on the fast path (potentially per > > packet). We could s/u64_stats/u64_seq/ the existing helpers. But that > > sounds like a lot for a single user. Dunno.. > > It does sound like a lot of a single user. > > And what is the likelihood of this device ever being used on a 32 bit > system? It is a server class NIC. Are there still 32 bit servers in > use? > > Maybe "depends on 64BIT" with a good commit message why? Will this not apply all new MMIO devices? They will either be high enough class to be only used on 64b systems, or built into a 64b SoC. No strong feelings either way, but I think we'd need a better defined guidance on when "depends on 64BIT" is acceptable and when developers have to go thru the pain of using u64_stats_*.