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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4F48CC433F5 for ; Fri, 22 Oct 2021 09:49:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 29215610EA for ; Fri, 22 Oct 2021 09:49:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232134AbhJVJwM (ORCPT ); Fri, 22 Oct 2021 05:52:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47940 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231992AbhJVJwM (ORCPT ); Fri, 22 Oct 2021 05:52:12 -0400 Received: from mail-ed1-x52b.google.com (mail-ed1-x52b.google.com [IPv6:2a00:1450:4864:20::52b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C93C7C061764 for ; Fri, 22 Oct 2021 02:49:54 -0700 (PDT) Received: by mail-ed1-x52b.google.com with SMTP id a25so4984723edx.8 for ; Fri, 22 Oct 2021 02:49:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :references:from:in-reply-to:content-transfer-encoding; bh=qs3gIqdbkRBGBfsg9ypoTQYjDMosQFEn1tkf9xVNOkQ=; b=F0TeB10CghmHv1DlzrwsDSi/w/X1VJJUBMioIg1IsfNGc2+ApOoGzG7F5KazK2z6Oe 9I4gM8WbLL1lPTcxdqpVwXS4c3IhVoXdRGn6oWHVGVrrFqRC2NDwfgIHj+7CXSnocOpE I18vGC9Jned0VY0gFjy1nght+mwMywiMz57+TW+4GR092cIIX1eIY/c75hDsZp+XeQOF kY/fLZlZpAe8k0Z5n8T7Um4HULGBf5UilpBTBtXffCxlIzwrUjVH1GaN7IrIxwHqeH0Q 9aKlNPKrBxr4R7iKDxpY0DxUW56NuDiH4rZ7bbOtIrzvqvrTbT9peJVNQKhx2j4YOvI0 1FYQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:references:from:in-reply-to :content-transfer-encoding; bh=qs3gIqdbkRBGBfsg9ypoTQYjDMosQFEn1tkf9xVNOkQ=; b=BGYl5ShAkVSJXcmvTG1og5ULcGctIqsq8+X6GvpqaZKDC+ZUBNLKrq/vj9RyBsYDqT xnZvDOShZWQoYaoIrLNLhqNui48tiklKKlu8AcfnpCglnkvXQFIZN62Kz00aKRaySNfJ PqRQQdyaeNxx1PwDPiBMdASZ6dGv0sxT2ibkDwSPmjqQHpDBGXQFKEPjNhbDYrKkP+B2 RdMLWx3dqQ1K+h8H/MVatTXbLxgWFVKpShs2YoFeTArUMU4rHltqMG1FxWKZfD5KQHb+ G9sR7R5wRhTmmpSSkN+XN601rvTOKZnSTxnsVio/Ma0DHvzV/NGPlkPhOe5aUYMw9TUb SNUg== X-Gm-Message-State: AOAM533AzbdV8Wq57+Qr8VKo4oWxUpcXCP2mZ3cUVqppltTcagb0q8Ge nHQMoUvOFWTvfBIRY1lFtuFG8mkXpi4= X-Google-Smtp-Source: ABdhPJwWIj0KM0Bmv3pPNUwsgV2cVnay7ucdDp1fn2Uw5IyZXDImaCs8m3wb5zQbO6dilfzLaybMfg== X-Received: by 2002:a50:e1c4:: with SMTP id m4mr15499453edl.307.1634896192025; Fri, 22 Oct 2021 02:49:52 -0700 (PDT) Received: from [192.168.8.198] ([148.252.133.195]) by smtp.gmail.com with ESMTPSA id g7sm4226955edk.13.2021.10.22.02.49.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 22 Oct 2021 02:49:51 -0700 (PDT) Message-ID: <01fd5aeb-68c9-c30d-be9c-b8ce21f2f16b@gmail.com> Date: Fri, 22 Oct 2021 10:49:55 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: Polling on an io_uring file descriptor Content-Language: en-US To: Drew DeVault , io-uring@vger.kernel.org References: <70423334-a653-51e3-461c-7d09e7091714@gmail.com> <1e3b5546-5844-bbed-e18a-99460a8ae3e4@gmail.com> From: Pavel Begunkov In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 10/22/21 08:59, Drew DeVault wrote: > On Wed Oct 20, 2021 at 2:00 PM CEST, Drew DeVault wrote: >>> Surely should be updated if not mentioned >> >> That, or the constraint removed? The reasoning is a bit obscure and I >> suspect that this case could be made possible. > > So I dug into this a bit more, and the constraint seems to be to avoid a > reference loop when CONFIG_UNIX=n. I grepped Google and SourceGraph for > "CONFIG_UNIX=n" and only found two kernel configs with Unix sockets > disabled, neither of which had io_uring enabled. Given the rather > arbitrary restriction on registering io_urings with each other, and the > apparent absence of a use-case for io_uring without Unix sockets, can we > just require CONFIG_UNIX for io_uring and remove the limitation? It's potentially problematic, even now we have a couple of other spots relying on it. Is there a good reason why it's needed? -- Pavel Begunkov