From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 0B6A7239082 for ; Thu, 27 Feb 2025 14:39:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740667199; cv=none; b=TiJ8ot73rx/kCpc8njG0tPeChdaNLuZDT9fxyET5GFNoMMX2AutJVxsOnizsojYA63BN4iIhhHzWQ8zVvcjXpFo1pdh/ehyCT56jnyV4nxlvng3b80ijXsZsqPYvkd8npCiSHyzrVZgQAQCxCw9h2u8N9Q64PYdXcRyTM/phja4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740667199; c=relaxed/simple; bh=3HNj2lcv7MZvcwGA/FLxym27Q2rgYaCGFXQoXk1HxUI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=WyxQ1CMNIYnjz5Vu0mFi3beN7PGp8lYRpg0yEK4z+ZRYw0WsPhg9//+J9zNt8kvxxZlb99EIy/x8/sXSXYuhgQtIsbfVLcUBTs+Zz0KkCpOl5nBNOn4box85kQwsBM9gCPtpyQD5l0AHGFjKdPRFzYwDOT/tgUy+cowGTVU1UuI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=AYdYQIzI; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="AYdYQIzI" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1740667197; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jyqUBZB6nKc/r+VKm621tlxSSaBd845l3542H86vZ7E=; b=AYdYQIzIu6gczQSz3f1wWqhXMQv1Fq6U8Fp+yVJfWtcw4JELv53h2bgYDGseVUydbbbT36 ClUvy5y/CtYf6X2gA2J1zSsMtmmea4HiY+FwyOL6tdt92l+ZF9aggxViAgB+BN/vxNppDa Uxg4DjT7Hi2SkNpPxdvwIoETHzPxwgU= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-313-uLiyrFC3OWyFmuO2vyFGKg-1; Thu, 27 Feb 2025 09:39:55 -0500 X-MC-Unique: uLiyrFC3OWyFmuO2vyFGKg-1 X-Mimecast-MFC-AGG-ID: uLiyrFC3OWyFmuO2vyFGKg_1740667194 Received: by mail-wr1-f69.google.com with SMTP id ffacd0b85a97d-390d5f1e05cso393389f8f.3 for ; Thu, 27 Feb 2025 06:39:55 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740667194; x=1741271994; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=jyqUBZB6nKc/r+VKm621tlxSSaBd845l3542H86vZ7E=; b=oIhHMTAZnGgFkyiY7gcR5o0s3ytbJJJbPBnBlKP4zkEqqKGGfMFglu59rrIvjKnKBX OWu+Fw3E3VGy1V044OH8cDmDLAW6FtUlgeUs37pUlAiygLJijb6YcwVr3PtCfESB2tSg uva5HdHTub/P3ozpXVxcA2A3utAHP8MVjrNlrOyynPL0lHOoZE6RWBjmH1byM2kNS5K+ Acsr8Y7frNi8o0KUMnp7/6KtVMKA0+sHuQE7aIiRrXVsaOHa4ciya4ZrcaEJT/+5oaRn Y4lYFtgXuN/3TaUquVoT1nNAMx4/7vpfVBgsJWSERkFBeQODBjurs+vTVObCRDf7uJZ0 4lLg== X-Forwarded-Encrypted: i=1; AJvYcCUQar/H85712X0sdaOML35hYl94CWP0qfMBt5RRDMmnzPU2FXPewBWULVJb8MdN8jVlFxX+3JS2uE22Crg=@vger.kernel.org X-Gm-Message-State: AOJu0YwXXCNqiGoxP7+edacS1FYRNWf3CPmcIFAKIe9x1y5L3tQfVM9E Sg0FIzEe9yvLg/+TOy0HrOxIa4SCGAYDt5FIaMAoAUClD4vzcq+aDJkyBtjXOkXwxb2GNsIUco7 1EJV6gPqS+I/oIbVcf8zsrkprnWylvFzW+FcUlSWQ564A65dJ8ONVcR9bueMsm8GW0WT6qQ== X-Gm-Gg: ASbGncvH+HXvWXb8aLAkjwyX0tfiP2Vii7jwS61xdbOOvfsUf7WHQaT/VP/5BEo4Ab8 GDnUv6XIRl3tMNGc7uOdLFQBfzxITEhruq6EYwI8FWM3cthTR+Jg9mOeNUmO1G9JhBFxak4aXim q92Ysu/9ro76R3x+b9rA4AtbEiYHlSA3zIxTkvTBfb6hi2M7XDxhpaa2vI21cQ9lN+ZFwQ3QCxq 1S3L2ry3LEGp0A/aRzeyTp501lHl/xKAA2EQyMQoCV09+G9fDkv4wOSXZ3jiDvvthZJRIOUa2O8 i9q1B5EEKSQnuEXEnQoAAlnkj9s17ZHFKx4ajRM9kdhM/Q== X-Received: by 2002:a5d:5886:0:b0:390:d6b2:c74d with SMTP id ffacd0b85a97d-390d6b2c8e2mr5688443f8f.35.1740667194116; Thu, 27 Feb 2025 06:39:54 -0800 (PST) X-Google-Smtp-Source: AGHT+IGcWa/eBKcaZPmm9VXX7NkW/71dFoXSJxP3YfdCAmJI+JSIQx4UhJs1j3Idz3PrIeHcoy0Y2g== X-Received: by 2002:a5d:5886:0:b0:390:d6b2:c74d with SMTP id ffacd0b85a97d-390d6b2c8e2mr5688418f8f.35.1740667193800; Thu, 27 Feb 2025 06:39:53 -0800 (PST) Received: from [192.168.88.253] (146-241-81-153.dyn.eolo.it. [146.241.81.153]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-390e47b7b6asm2336666f8f.51.2025.02.27.06.39.52 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 27 Feb 2025 06:39:53 -0800 (PST) Message-ID: <5913bf70-de74-4915-9ba1-9cd92dde6945@redhat.com> Date: Thu, 27 Feb 2025 15:39:52 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] pktgen: avoid unused-const-variable warning To: Peter Seiderer Cc: Arnd Bergmann , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Arnd Bergmann , Simon Horman , netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20250225085722.469868-1-arnd@kernel.org> <20250226191723.7891b393@gmx.net> <4c260b13-3b08-409d-a88a-e5bbb3c18e03@redhat.com> <20250227152154.4da61f2f@gmx.net> Content-Language: en-US From: Paolo Abeni In-Reply-To: <20250227152154.4da61f2f@gmx.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/27/25 3:21 PM, Peter Seiderer wrote: > On Thu, 27 Feb 2025 12:35:45 +0100, Paolo Abeni wrote: >> I think the unused define is preferable; I think pre-processor defines >> are cheaper than static const. > > In which regards cheaper (out of interest)? > > Both (with and without static) produce the same code see e.g. > > https://godbolt.org/z/Tsr1jM45r > https://godbolt.org/z/6sr1o8da3 I must admit I was unsure the compiler would always optimize out the constant. I guess the macro could still produce shorter build time (by a few clock cycles, nothing measurable ;), so in the end it boils down again to a personal preference. Cheers, Paolo