From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f51.google.com (mail-wm1-f51.google.com [209.85.128.51]) (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 DDB1115853B for ; Sat, 22 Feb 2025 01:14:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740186846; cv=none; b=EvSolvYEJrIKO9tYwBZnaygTn8cpRapineiXu8cvpAGtYdB0LYfcKYSxOgu672ctKZIJ2NYTzH5ww9msPQk2kYb2pCam6egcg4Anc77221HdO3PTmYDFvocTFyMdRyOSK+53r8dLEMHxbfZPcYNwKppfWQKbWl9/hjVsQRx8l2o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740186846; c=relaxed/simple; bh=K4yQCtH8PO5z4ATGi8+ol/rd512t002Cq4YHUILnVyc=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=O9/v1aCd44j22tjRuzAQeUm5+iW4hLTDH/Sv7ExTSU0qVrm9rtbndd4zdGpbc3JGgJ98etMldHREA4X7dByQf16Z4K8Eh56hJuQJSl9WxpHzhKWrDjVMwP/Hse43m4WXgOUOZL6aLux3mJLbtlGzjNv/mTm6clv2VBz3X5GafBU= 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=nT3+1H3L; arc=none smtp.client-ip=209.85.128.51 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="nT3+1H3L" Received: by mail-wm1-f51.google.com with SMTP id 5b1f17b1804b1-4398c8c8b2cso27031285e9.2 for ; Fri, 21 Feb 2025 17:14:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1740186843; x=1740791643; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:to:subject:user-agent:mime-version:date:message-id:from :to:cc:subject:date:message-id:reply-to; bh=I5GOlc5mP7gLWQonKRGoDJ8d8RkjwWcaStwIa8BFjAA=; b=nT3+1H3LGWkFcDZ5QMKccapee9hy9HcOirqG6YxYaD2OHLlcX1MDqz3cKobmLilscm fZEm9QiRqEBsDhOxmZmiJG7ZdJzHFtweovSPfY1kykYrPIa5s2/mj2/HqRGbcG7fREHu Tp8j1M+m0DICGPUcZP+tlZQq8X5Ys3pqIezDvBWYbU+1ASNaeXGgLs4+FBFW0UzUkJDb r3vdWKJKwFxCtA6F7geX+Ge+xEIIImN4bYTJtCBUWrsD6wbX20sMdwE5Oecj9D8AOyl/ tyGkmXu7V0lN7LNTEMEpzcuOnzAPyrxxMMwo8C3z62EoPyJ/+vn8YAYlFkHau9Dp09SJ IRNw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740186843; x=1740791643; h=content-transfer-encoding:in-reply-to:from:content-language :references:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=I5GOlc5mP7gLWQonKRGoDJ8d8RkjwWcaStwIa8BFjAA=; b=FCkTpNro8R7B1zlspnJFcA2ve7qQCltvt4Q33Ka+1oJKqRqPH7SwTV7vpVsmS1VPwQ +NDc73WD5N4RHJ5HHukd76lk95VRtJ6sqM03rwQ4hxHNVDs9fucN3RtwmkglBKvJOoMT WLoF+IRkeaOF5GNZ0htNysjhVETrZH48lX4kHw8vTtbV1k4mUsO76r4u0GXasOX7dyVH HWRu6Xfljus8dK+Y/P2sfA0KqzDk3qcr91FWnIBwKxQjTQawRxk7V+MEiyHaWmU8GNx4 9diZJqEC47sajjG3C4pG/4binAX1EGvJrQWadRSxd4XZ3o0035EatF4cRMwp7g013Aru OLjA== X-Forwarded-Encrypted: i=1; AJvYcCVVSnVeygLKlQtCLwdzeg9HRuqnotJPA+oFFK7H5N4SSSnhZ2wUpKmCp3Oc18KzCAkhJa05dthiBg==@vger.kernel.org X-Gm-Message-State: AOJu0YwIFmwaZq/X449egKfbIrSrrodLulrSfaPuYOR4JHh+L9eb2OZd WFz3LsP8GRzzP1P0OR8r3MQBb+tE5lzhWwFrUOsKqf6SjYr0NvMqTq66XA== X-Gm-Gg: ASbGnctu8h73ISUKte49GKBzDozoXgtpGtvUB+VK8DBwaXDebLjRsZ4Z9AyLmDBShc2 myyis5FSy0B+FFCkZ2o1s/F6CxJVaVYRmlYgaM4JWF3IzZVSqHOT2NbNfZUdrTEkTlnYLZcTvDi z9lRDD8dZwHbHTCDPYCRUBDvBmskfWJZCViDAROouTg5Jl+caolVSF/lLaFdLSbjVVW9qgpKKeH ILFpRC9/pFjx3ZUI09aLs06Svz6Cb+oBLd1KOK6ZUpug5n3YfJIjOwkinu+GKBOw/57j4Bhp4Az Tk7+ovizrpp54OK9+ej4kBoa5hHUgBoL/n5s X-Google-Smtp-Source: AGHT+IH05QM91HU5/2NJtkKy3dprt6BSaasst1pQ/wK3a/IS6ReSnAVVxpkvh3lici9DxcdJ6URouA== X-Received: by 2002:a05:600c:524a:b0:439:86c4:a8ec with SMTP id 5b1f17b1804b1-439ae1f1147mr52146855e9.15.1740186842901; Fri, 21 Feb 2025 17:14:02 -0800 (PST) Received: from [192.168.8.100] ([148.252.141.194]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-439b0367577sm32419725e9.25.2025.02.21.17.13.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 21 Feb 2025 17:14:01 -0800 (PST) Message-ID: Date: Sat, 22 Feb 2025 01:15:05 +0000 Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/2] io_uring/zcrx: add single shot recvzc To: Jens Axboe , David Wei , io-uring@vger.kernel.org References: <20250221205146.1210952-1-dw@davidwei.uk> <20250221205146.1210952-2-dw@davidwei.uk> <6165d6a4-a8d3-4c2f-8550-e157a279c8f3@gmail.com> <516fdf90-1f0a-4c2e-b7ed-23a72b7a4342@gmail.com> <13ebc224-a280-4d60-89ca-d777dc7553b2@kernel.dk> Content-Language: en-US From: Pavel Begunkov In-Reply-To: <13ebc224-a280-4d60-89ca-d777dc7553b2@kernel.dk> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2/22/25 01:09, Jens Axboe wrote: > On 2/21/25 6:06 PM, Pavel Begunkov wrote: >> On 2/22/25 00:52, Jens Axboe wrote: >>>>> @@ -1250,6 +1251,12 @@ int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) >>>>> zc->ifq = req->ctx->ifq; >>>>> if (!zc->ifq) >>>>> return -EINVAL; >>>>> + zc->len = READ_ONCE(sqe->len); >>>>> + if (zc->len == UINT_MAX) >>>>> + return -EINVAL; >>>> >>>> The uapi gives u32, if we're using a special value it should >>>> match the type. ~(u32)0 >>> >>> Any syscall in Linux is capped at 2G anyway, so I think all of this >> >> I don't see how it related, you don't have to have a weird >> 00111111b as a special value. >> >>> special meaning of ->len just needs to go away. Just ask for whatever >>> bytes you want, but yes more than 2G will not be supported anyway. >> >> That's not the case here, the request does support more than 2G, >> it's just spread across multiple CQEs, and the limit accounts >> for multiple CQEs. > > All pretty moot if we just go with 0 as the "transfer whatever length > you want", as obviously each individual transfer will be limited anyway. > Which is the better choice than having some odd 4G value. I think so as well, and we'd need to check for 0 otherwise. And it's probably fine to reserve a U32_MAX as above if it has a chance to make (even if in the future) handling easier, not like prep is performance sensitive. -- Pavel Begunkov