From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f177.google.com (mail-pf1-f177.google.com [209.85.210.177]) (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 739E41BD9DC for ; Fri, 1 Nov 2024 17:05:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730480737; cv=none; b=GbidxTkZ9VRheUvBZ2i7z4RP2md+Ahwi+4FYUArbJyBa6c92NTkZJkLvwUKZFn4VWjLDBPBdvqQUrimDG3clZGwzo8puJfZETfUA1YExVKDK7znC/DAhmNiRMBStTT/V6UcyTpF3jbcMd1Qy/mIxoWjUCsEhZ185jOIAYkK1U0U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730480737; c=relaxed/simple; bh=5MhF83ZwmDeykwiUmDiXoDOvTxSlseeEZWvpoZUfQLk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=OQD1Nwq1KZrqAUFb6nE5MWiCAWLmjDQ2s1yHlVcrzKhdW0zxdB4Ye0SR0XUvK+2pn3xARQrhVRQATT6kzjXkuJGGGcYYErcgeNMq6M4mEbtlB93UPhEMuQKfMPUlW1wG0E0uReizK+FLUHvX0OxoqWKL+jaZmNAU/Q5fFzcmCNI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=wEEh4l2y; arc=none smtp.client-ip=209.85.210.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="wEEh4l2y" Received: by mail-pf1-f177.google.com with SMTP id d2e1a72fcca58-720d14c8dbfso778632b3a.0 for ; Fri, 01 Nov 2024 10:05:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1730480734; x=1731085534; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=qfYyy1SbPldcPSzTabocTJt4jPShqf+lAsxrzapGsfA=; b=wEEh4l2ydSuaN4XHTy0wPsfFE76RaqN5DlpLdpHPfxIv02EE6bN8qiaUH9fmvfDvIz keVg/VcouIIJPMZwOAG+CkAvbK+7MXE417RzVH8pyMtrKyZIyaIUib6oXEQNeLBV7uiV +W7UonwBa8ACTh0PqDgdsO3uarpy6QGTzJXG0Q5BDEfG+hvmdY0mHKMMgmXF/iCRaBAL fyLpiVZBH9vwqwP7eUUv3KsFm+EZ+WUad+pyfPmu01pQqyuSXzXZILkmLgUHyWQaQiwl Xu9JO2Efudlo0RDSGCGOspRXONzRNVaZK23p3nsQ8ME1ZfdBd4DqWvaz8HeTOP9HkHw7 kYIQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730480734; x=1731085534; 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=qfYyy1SbPldcPSzTabocTJt4jPShqf+lAsxrzapGsfA=; b=DGVRs/F0yy8dGm4kfviLjEHJZEa2R0XE2dzVxbhYlPXE8bXa+dIqMWYQo8AdDIW+LP JlgLvv24/0h1i0wxR4nJevOpviJ52Z93lT2tun2lsON2q3EkK99FJ/Wxailwg0RliOA9 GDHEzv+QlfA/ybP6Vb7sLD7pomOmKTNwfm6Rno82IQz9mkIp9AIC38yoAnyaUomUazZv mfVtxuRxINPLx4KcOEL8Jb5VQauDrDEYmbdLdvcqBvGbuKSoXicxIqIuwHZfbvOoNniJ HwRIFZ03JVChn6qKhVjZ1aRkrU06RThm4DXcJghdRp7rAiASq4AtB+EwAZZyaauMtCVA nScA== X-Forwarded-Encrypted: i=1; AJvYcCXMzf6HODPHykp3nWfIJM/ECuQTYeWWFcRw9kjrWLLoGGr1nMStUDzVVQnC9sk3XVPV15N97RAaPA==@vger.kernel.org X-Gm-Message-State: AOJu0YxeBXw5urM6gKn9ffOuOXhaL5GlV27M3aATabeNI9fuW+mTi3iQ JpTvx53hj5xyqlRZYC+B63rND5NeOesieQ/l15PngEAdeCZQraiEbCCDd7N6stA= X-Google-Smtp-Source: AGHT+IFEpSoLa4Lh5tuK3yFGnGdOon09ZNkzct8SP5ECXFTA2gPiypPv1QwGFI/VoOm+WHxHh5Kugg== X-Received: by 2002:a05:6a20:ce44:b0:1d9:1cea:2e3d with SMTP id adf61e73a8af0-1db91e5f887mr9746082637.40.1730480733596; Fri, 01 Nov 2024 10:05:33 -0700 (PDT) Received: from [192.168.1.150] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-720bc316a79sm2823926b3a.205.2024.11.01.10.05.32 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 01 Nov 2024 10:05:32 -0700 (PDT) Message-ID: <8ed55d21-f66b-48a7-ba94-64f6b834ba54@kernel.dk> Date: Fri, 1 Nov 2024 11:05:31 -0600 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 RFC] io_uring: extend io_uring_sqe flags bits To: Pavel Begunkov , io-uring Cc: Ming Lei References: Content-Language: en-US From: Jens Axboe In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/1/24 10:59 AM, Pavel Begunkov wrote: > On 10/31/24 21:22, Jens Axboe wrote: >> In hindsight everything is clearer, but it probably should've been known >> that 8 bits of ->flags would run out sooner than later. Rather than >> gobble up the last bit for a random use case, add a bit that controls >> whether or not ->personality is used as a flags2 argument. If that is >> the case, then there's a new IOSQE2_PERSONALITY flag that tells io_uring >> which personality field to read. >> >> While this isn't the prettiest, it does allow extending with 15 extra >> flags, and retains being able to use personality with any kind of >> command. The exception is uring cmd, where personality2 will overlap >> with the space set aside for SQE128. If they really need that, then that >> would have to be done via a uring cmd flag. > > Interesting, I was just experimenting using the personality bits for > similar purposes I mentioned but in a different way, and I even thought > if anything it could be used to extend sqe flags though I'm not a huge > fan of that. We're going to need more SQE flags at some point. At least with the potential to extend it with a setup flag in the future, we can grab the last one and have that other option down the line. I don't mind grabbing personality. Obviously it'd be better to get free space somewhere, but there's no free real estate... -- Jens Axboe