From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f54.google.com (mail-wm1-f54.google.com [209.85.128.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A54BB1F9F7A for ; Sun, 25 Jan 2026 22:38:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769380697; cv=none; b=f+BB/A3aWiunETVCHJmwZEgB6Hv4LJykCgj6adZyzzH6Y1nuHw/HLwzeh/e6Q1K9A/jFcLAC1BAwbmbphajXwevMnHy4nwSg++iBN+5cQbTfs74Aot/KJyjeDxeUiTGw5SO3HSew6eDavjLimrlI5On+hYQXMzyHCxGABsYC/8U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769380697; c=relaxed/simple; bh=bShR+DvzxtrfjAzpYpHrf19jxtgKZ01PGTNh9LJuV2Y=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ry9OgvxRf0iZv+nO9Pc+2N3cUYQ6IdGI0TEpYbd+H5DBMed/uE2Lj/bjaKodj+loM2qZEsMUQHLDhUNmQ1tx5qUAW3rsh0aIDZGCrY6yoo2g++2VCWXa67jiGqOH413a3eaWFy5b5wN/PcGWjcrHKaTwuf8/NTMTQ3qWLY2smUU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=i+HwabPe; arc=none smtp.client-ip=209.85.128.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="i+HwabPe" Received: by mail-wm1-f54.google.com with SMTP id 5b1f17b1804b1-47ee0291921so33075905e9.3 for ; Sun, 25 Jan 2026 14:38:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1769380694; x=1769985494; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=2umcnwEupH/jiJ8gD8E4VSgSAY8v1C2B2I4eeqRnGkg=; b=i+HwabPer2NLHrOA4q7Dn2W3cf24MoWNVWCYh9At4NDuco5iMFfsKqGQH96UgWqNeR qHKuunOyhNmlREYsWz+I/Xmymoy3vmC0hBPohjyjehLCLqVgmHnRxbKaQSw/SQBgZeCI BSrZkUpotLZCVN1A7vftXQJVaCoborg+KPxq7L/dVSrPce6slctbukmRyhoAYFWdcAJF UyaZmGWhfq7HyaHCsf92J7JwV026FpjlZ1nNoYvPYG9n4QcBt2xX601Y1o3/IeUyl+Ru PmsTV+n/Rd7TN8jFPfgYP2QvVRi3BVt8v5hV1slijhm9BC53KoZaCoBa14cNH9KOU+qd ztfw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769380694; x=1769985494; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=2umcnwEupH/jiJ8gD8E4VSgSAY8v1C2B2I4eeqRnGkg=; b=Peqn48aaRelhkJy31+pxNAqG1Drd1MvbRdo2ECOPDJovEWz63NqtXvYhaKDeVL4tSF wJXFjz+BziojP2j+WBw7NmfHez2VTU5FHK0c3HwNxbwpL/AbAEkW4IZyKCzoAIKiOPWD 8UsKjKoYmAR5hMKj01n0vJBr3gakZqoTKcgziYGQzXzbryBDj4W95AQf9FumA4R2OtTa XKQ1WkpdP3RgbxIV+R48QnzOUtmqdZK3sl6yFdWIC/DJZQwVViay/thW02FFlLD+T6w8 JNtfI6mZ4bFBvjQ/QyayjW0MHl9VIUl5EX0cl0clwd8X4WemK4xqk70zWQd09xdeteYL qtgA== X-Gm-Message-State: AOJu0YwW/mbnDcssewWmMBDkinLejflUYuz4w/myE/xFZqTgRx84nXWt vTUY58SidzAuUxuAs/A6OkICo9nGndTc1m1Z7iN8zNAO+ZNpgWi8EXCf X-Gm-Gg: AZuq6aJ6aYlqJ/MnkMCEE1B6/UY2DroN/4EMf6kDpXlfN50NRcDCgB3KkfzjZfDcJL0 0J1vGfJcp1vrgdp8WoCvPke9UAPAFldW06SDMT9hdqG2AmYkCI9WG8hflcjZ5GXhE9Ic/pOcU2y vcmVCcedGeamKoi8SeD1gFb7zpKaMXM4fjouOxNqN98gJ1ckVYMQ6g3zNSCgBpA4F70e/pGzHJr tDSi5jkwplZ/8xH4KCEuhuOR3pqKo+XLkcOswZr/vPCJCuxYcK56MWYNNhG4L+AATXU2MHkwNQx JLGv4J+iKRfkc6wwp2QwXGLkO5JWAfI89wlST7j5872KXUcpKIF+16uFNEE9VXeGd2MiMpGwOAj 5DHcL7wUrjnNR2x20wM/YJoJvDFIhzfEqAz75MYstQ7YndK7lX1r0NaPOaHiJ89S4zUIKgM51Xq g7089Yb2dwF5Q+vebpYmwPnuli9VoTE36fSRQdPIrEWncf7GEKObZm X-Received: by 2002:a05:600c:4684:b0:47e:e20e:bba3 with SMTP id 5b1f17b1804b1-4805cd44c41mr49205745e9.7.1769380694028; Sun, 25 Jan 2026 14:38:14 -0800 (PST) Received: from pumpkin (82-69-66-36.dsl.in-addr.zen.co.uk. [82.69.66.36]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-435b1c24bedsm24336005f8f.17.2026.01.25.14.38.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 25 Jan 2026 14:38:13 -0800 (PST) Date: Sun, 25 Jan 2026 22:38:12 +0000 From: David Laight To: David Yang Cc: netdev@vger.kernel.org, Lorenzo Bianconi , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next v2 1/2] u64_stats: Allow u64_stats_add() to accept s64 Message-ID: <20260125223812.3a2ae148@pumpkin> In-Reply-To: <20260125220753.3984326-2-mmyangfl@gmail.com> References: <20260125220753.3984326-1-mmyangfl@gmail.com> <20260125220753.3984326-2-mmyangfl@gmail.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) 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 Mon, 26 Jan 2026 06:07:49 +0800 David Yang wrote: > The current u64_stats_add() accepts only unsigned long, which makes no > sense as u64_stats_set() accepts u64 already, and causes unnecessary > narrowing on 32-bit architectures. Isn't is a chicken/egg? A value over 2^31 could just be a very large value that needs to be added. Where the add is being done 'just in time' so avoid overflow. David > > Moreover, since there's no u64_stats_sub(), users may be tempted to > reuse it for decrements, which already happened on nft_counter_reset() > in net/netfilter/nft_counter.c . > > Change to s64 to allow both positive and negative values. > > Signed-off-by: David Yang > --- > include/linux/u64_stats_sync.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/include/linux/u64_stats_sync.h b/include/linux/u64_stats_sync.h > index 457879938fc1..e77f2b30bac7 100644 > --- a/include/linux/u64_stats_sync.h > +++ b/include/linux/u64_stats_sync.h > @@ -84,7 +84,7 @@ static inline void u64_stats_set(u64_stats_t *p, u64 val) > local64_set(&p->v, val); > } > > -static inline void u64_stats_add(u64_stats_t *p, unsigned long val) > +static inline void u64_stats_add(u64_stats_t *p, s64 val) > { > local64_add(val, &p->v); > } > @@ -125,7 +125,7 @@ static inline void u64_stats_set(u64_stats_t *p, u64 val) > p->v = val; > } > > -static inline void u64_stats_add(u64_stats_t *p, unsigned long val) > +static inline void u64_stats_add(u64_stats_t *p, s64 val) > { > p->v += val; > }