From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-io1-f42.google.com (mail-io1-f42.google.com [209.85.166.42]) (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 525F6195811 for ; Fri, 11 Oct 2024 17:57:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.42 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728669459; cv=none; b=Z9Q66rlWua1QsC20F1/YOeTSSR+tcObMQVmJ/EhSI+jv1PTIuPFh4P61OIUN8KmpZrnmLaBi2RVPYj82Lv4KCC8ghJ2RXYxut8UsE3vco86GfhydB+TXPlP4ARBk/az6r0aUAFuSerZN73SnZqWBN12VuV1vIfudWbcWc/QiqAs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728669459; c=relaxed/simple; bh=HASNl3baFUk3DXkPtqWpYSx2LvLmgC0Uc3d6ylrr+40=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=h9oegUcM0VRGc4USlz4Gd8zl8RbbBk1RHfKpo9mnLZ7hSJ2dsveoDzPtDsmrauIS3zGdDZ5IatIzQbnuNIMocJ9mrVv0uZqEsY8tsAudHmDEf4pESmF1a1wuZGja56NUgK6zJmu0RRYwym8zDnK+aybKYY8MVlKBOX0HYnMaT/s= 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=SGDYoiUG; arc=none smtp.client-ip=209.85.166.42 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="SGDYoiUG" Received: by mail-io1-f42.google.com with SMTP id ca18e2360f4ac-8354406f92cso88085439f.0 for ; Fri, 11 Oct 2024 10:57:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1728669455; x=1729274255; 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=8X8KlpY2k8rWPiQoC8GoUeonTyZni3MXAErkSzr+wmg=; b=SGDYoiUGI0ORbmbBp88X/5T0o7yPX5bDYk9Tty4VysEVXTCjypeVmo+uzDaOXIQ2al o+YKpBpniciBmm//nzn90h5RK3h2CI5QO4fLfDzWdOaIpATfslo4CIF9Koc7Or5eY5KS Fx7eTnLG8te3OUwjTHxN9jhCtEr/tZR4MUXF5a53BHJVkN6ZPIwQwy9WHD1G4DbVS2MX yBUv197Mzi7bxqDtl59icrGRLL5ICEHLiIV+w3J2n8L1u03P5sobY95GqO8GGamZvZOe 6tWio6yus1n+qPmsEdMks5VM34cisBLV/OECzEkvrh2gPqFTaJ9Vyf3yTa+F5WJBxGx5 il8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1728669455; x=1729274255; 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=8X8KlpY2k8rWPiQoC8GoUeonTyZni3MXAErkSzr+wmg=; b=wUl5jZ4pqVsdM7tegdh7tn7XbhpJxIbKwQ7sq4eZN+0DFZ1DP4onJi/u+I1rtpTlHp DxeiZybN5GPbvtGU4CNIeGbhCumS/XmjLJzYhBXwirdU7loWuSt6iccHPBL63FjPBiol JAyO1OajZsp6h2AsWioX9te6125S4N+lJsC+jR3bpE8Zw6iKDKZW8c5Pm6iEyIFfLdRM wlnvex7dVj60G/HDzuFhjHdncP9q065zEsTs9a0bEFN8G7ssIIhrS6DRcgQwPntygwgp HcxOlcu4Wn+1rg6KqUsa9v97Ec2bNQNPEYOjzEjNP7ajBYFPgaE6XFl67BX9q/5TXkTD vxpg== X-Forwarded-Encrypted: i=1; AJvYcCWO+EwumevwUcwUdOgvqbobePYxi40Q/zxE77GY22Z317X2FzwttDwBVC8JBngjmQ36cDygIE+IRA==@vger.kernel.org X-Gm-Message-State: AOJu0YxcmLaupMHH6w+ju32YZXB3Vpi2maiPnhEusxdlvr4nyneTZ2H1 zM55DOrAaVGCrvbB6BuJz2eqhieTVyvdDGawdb3sIxFwU9sKtFWj3uAlrWwjb2A= X-Google-Smtp-Source: AGHT+IGK4jkXMNvgxN1U3c+bu2mfsU0aAb28nw6kmPhvbFwFGoc8ErzxILM4AlO9MNCCTvFwTSRenw== X-Received: by 2002:a05:6e02:1c06:b0:3a2:762b:faf0 with SMTP id e9e14a558f8ab-3a3b58ca80fmr19886515ab.11.1728669455315; Fri, 11 Oct 2024 10:57:35 -0700 (PDT) Received: from [192.168.1.116] ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id e9e14a558f8ab-3a3afde45e8sm8008935ab.63.2024.10.11.10.57.34 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 11 Oct 2024 10:57:34 -0700 (PDT) Message-ID: Date: Fri, 11 Oct 2024 11:57:33 -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: Large CQE for fuse headers To: Bernd Schubert , io-uring@vger.kernel.org Cc: Pavel Begunkov , Miklos Szeredi , Joanne Koong , Josef Bacik References: Content-Language: en-US From: Jens Axboe In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 10/10/24 2:56 PM, Bernd Schubert wrote: > Hello, > > as discussed during LPC, we would like to have large CQE sizes, at least > 256B. Ideally 256B for fuse, but CQE512 might be a bit too much... > > Pavel said that this should be ok, but it would be better to have the CQE > size as function argument. > Could you give me some hints how this should look like and especially how > we are going to communicate the CQE size to the kernel? I guess just adding > IORING_SETUP_CQE256 / IORING_SETUP_CQE512 would be much easier. Not Pavel and unfortunately I could not be at that LPC discussion, but yeah I don't see why not just adding the necessary SETUP arg for this would not be the way to go. As long as they are power-of-2, then all it'll impact on both the kernel and liburing side is what size shift to use when iterating CQEs. Since this obviously means larger CQ rings, one nice side effect is that since 6.10 we don't need contig pages to map any of the rings. So should work just fine regardless of memory fragmentation, where previously that would've been a concern. -- Jens Axboe