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 F152A2F9C29 for ; Thu, 18 Sep 2025 21:22:11 +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=1758230532; cv=none; b=osMxzw1OKDgV4xDTgdXjqJik1fmb4RoeNCs1ChG1aOucedJfnfLZviq+cBBkLSILN82b5L3j9M3f1apbboUarlJ5CMTac2Im0Wy/sqSPlPuju7O6MMYM+5fWudtWlADh372kP84dBCV1TfVzHUJKnPXbefwiKm7LMcl5IKqXg0M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758230532; c=relaxed/simple; bh=7vqRJk4iBQ/Otl+4Rvp1QtfUCsJX0AOROT7QwyxhFh4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VjQNOGv4Cmr1Rjd5CLhMZOsPE6tTy3nhS7xSll72qYXg6jhjpbilJiVmSmeqQVLuYto8DuhOd1tVT/QUDKz3AWdg2ULEMd9kuppP9PWRx9XBtUi1uL1kDjcGp30jtnICOZSrh/El+QDHXujqDeeQ+uD2c/NRaLfY9F9fceJ/S64= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cSWDloZ4; 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="cSWDloZ4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8FB5BC4CEE7; Thu, 18 Sep 2025 21:22:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758230531; bh=7vqRJk4iBQ/Otl+4Rvp1QtfUCsJX0AOROT7QwyxhFh4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=cSWDloZ4itL9OJ5JZi4fYr7RU7BfCyc+VkzTsaR6zDjeuNR3bHW9jDQg+rChdtybR /ktQ6grFWymWKTXje2FDo2TF9cK4/hDiCyRQi7xFftdLi1MQ/THdhjFHmbY8louA6B SJNfyoD6VUiARV+zpo9bA5FlKBJfh115zVRwCtNC5aDGWTO/ZSzuy20+a7hOvgPa6a ZVPZVVtYwDsIzXYFVukPav5t4NJRNnpW8cDW0FlLyBt3YUB7/2sqYgUtVhedhhFJIX QX6SZtR9++l2jyh2Dz5m47kmOj3NUzkQ4wAgEnjYOJ6jtKsn3t4OYPPk7gERDvBSSe ScTy0n4iwd8BQ== Date: Thu, 18 Sep 2025 15:22:09 -0600 From: Keith Busch To: Jens Axboe Cc: Ming Lei , Caleb Sander Mateos , Keith Busch , io-uring@vger.kernel.org Subject: Re: [RFC PATCHv2 1/1] io_uring: add support for IORING_SETUP_SQE_MIXED Message-ID: References: <20250904192716.3064736-1-kbusch@meta.com> <20250904192716.3064736-3-kbusch@meta.com> <8cb8a77e-0b11-44ba-8207-05a53dbb8b9b@kernel.dk> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Sep 17, 2025 at 08:44:13AM -0600, Jens Axboe wrote: > On 9/11/25 7:07 AM, Ming Lei wrote: > > On Thu, Sep 11, 2025 at 9:02?PM Keith Busch wrote: > >> > >> On Thu, Sep 11, 2025 at 10:19:06AM +0800, Ming Lei wrote: > >>> On Thu, Sep 11, 2025 at 10:11:47AM +0800, Ming Lei wrote: > >>>> SQE128 is used for uring_cmd only, so it could be one uring_cmd > >>>> private flag. However, the implementation may be ugly and fragile. > >>> > >>> Or in case of IORING_SETUP_SQE_MIXED, IORING_OP_URING_CMD is always interpreted > >>> as plain 64bit SQE, also add IORING_OP_URING_CMD128 for SQE128 only. > >> > >> Maybe that's good enough, but I was looking for more flexibility to have > >> big SQEs for read/write too. Not that I have a strong use case for it > >> now, but in hindsight, that's where "io_uring_attr_pi" should have been > >> placed instead of outide the submission queue. > > > > Then you can add READ128/WRITE128... > > Yeah, I do think this is the best approach - make it implied by the > opcode. Doesn't mean we have to bifurcate the whole opcode space, > as generally not a lot of opcodes will want/need an 128b SQE. > > And it also nicely solves the issue of needing to solve the flags space > issue. > > So maybe spin a v3 with that approach? Yep, almost got it ready. I had to introduce NOP128 because that's a very convenient op for testing. I hope that's okay.