From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A1EC9C2BA83 for ; Wed, 12 Feb 2020 04:12:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 693E520842 for ; Wed, 12 Feb 2020 04:12:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=scylladb-com.20150623.gappssmtp.com header.i=@scylladb-com.20150623.gappssmtp.com header.b="gAGJPRTN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727883AbgBLEMg (ORCPT ); Tue, 11 Feb 2020 23:12:36 -0500 Received: from mail-lj1-f180.google.com ([209.85.208.180]:35822 "EHLO mail-lj1-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727602AbgBLEMg (ORCPT ); Tue, 11 Feb 2020 23:12:36 -0500 Received: by mail-lj1-f180.google.com with SMTP id q8so670802ljb.2 for ; Tue, 11 Feb 2020 20:12:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=scylladb-com.20150623.gappssmtp.com; s=20150623; h=mime-version:from:date:message-id:subject:to; bh=Ddbc8EZ31/HLaljcB/hWqG7TibOsoBF8nvuzDQ9pkhI=; b=gAGJPRTN7fO1KQDib1O1hZkmBgWdkLBAQQdCjWt45d4t1/nuR/rbWdyOu4WfYhJ4YJ vITDXX5A7ZB5RrPIKmQAmbbZSN8kNIHuerUpR+ydg+Sm19Oxwmie6CfSmTk8zmIm2KZp Xi+rrZk+kXJoCqghM+wf30OWPcxcKZ6Kz0kSU4slQkxJKmDinjGZrm2krPO22heKK7Ol 9ubN6T4GpB2rC/NQ0VFYI48DsGrPP9NKfwEzxOv2iPSqY4I0zpBL6ezTHB4zXiQzhcaG m8cJ9/yVeWtvVg/a9PkL8rzE69TLaC4AjHntgKH3DSbUoHcjcmexIhFojsI4YcjbLxGr 74ig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=Ddbc8EZ31/HLaljcB/hWqG7TibOsoBF8nvuzDQ9pkhI=; b=E9ikNHgaiWwFAd9AHkwGzFjTV2oJlUVajbFMNNkXPC1JomYU7vl+ul2doQNgTuQWbm zYWm8dLx24RtJmfdyaN4F8a5C1l+VUT51OOewOWzeeMEA+PMg2cje1tQtOiPmfb3yQ3R hq0vJv/FF1Tap83yf4FzP3kvmPED6HbpTFMEvYKdv4+5AvLlEDisWXoUKvHnIMd65fNH G8TrhiNwclHzNGEmpKSXZKsaFF+fv9pfKRI2vPir3SB1W+frWUqwiHrYL/US3zPqKVv+ zY+DrgRsxPJVcXhPFgcM/gZek30PX38KSHNlf7RNPZHk4fsuPv9UOe24ZLbHMc/JgLdF W21Q== X-Gm-Message-State: APjAAAWEG1d4n3QMbtN4zCnDHqb7B46PCXoYyr5clbp75LPweF05AFvQ b7DxQSBpUrfOmaHcj8bsWy+qMWrabpfPyVIKvlBwQ5zydv+ojg== X-Google-Smtp-Source: APXvYqxehAn2yjx3CmM6izrAKavS1EKO7WxqFhfu3IuyVnJd0xx0ORE77q6EcDnmtCORwyc/g6fZxXWpETChwUVmCsY= X-Received: by 2002:a2e:3514:: with SMTP id z20mr6296204ljz.261.1581480753403; Tue, 11 Feb 2020 20:12:33 -0800 (PST) MIME-Version: 1.0 From: Glauber Costa Date: Tue, 11 Feb 2020 23:12:22 -0500 Message-ID: Subject: how is register_(buffer|file) supposed to work? To: io-uring@vger.kernel.org, Avi Kivity , Jens Axboe Content-Type: text/plain; charset="UTF-8" Sender: io-uring-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Hi, I am trying to experiment with the interface for registering files and buffers. (almost) Every time I call io_uring_register with those opcodes, my application hangs. It's easy to see the reason. I am blocking here: mutex_unlock(&ctx->uring_lock); ret = wait_for_completion_interruptible(&ctx->completions[0]); mutex_lock(&ctx->uring_lock); Am I right in my understanding that this is waiting for everything that was submitted to complete? Some things in my ring may never complete: for instance one may be polling for file descriptors that may never really become ready. This sounds a bit too restrictive to me. Is this really the intended use of the interface?