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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 23FEEC433ED for ; Wed, 5 May 2021 14:23:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E797B61029 for ; Wed, 5 May 2021 14:23:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232283AbhEEOYu (ORCPT ); Wed, 5 May 2021 10:24:50 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:60826 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233054AbhEEOYu (ORCPT ); Wed, 5 May 2021 10:24:50 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1620224632; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uqMX/kcgxstoPmvY8Wd/zciVA9qFnbv7Kyz4Ssl4A3I=; b=q+jPs/ibe1vFk14EzFP32RiEk+khuaDqb1sbvNsjnQdnLzVO9H5M/j11YHjqJZ0ugu+3mq 7vTrifLgOeKwo0MstJ/rGJg0BN9//HwaPpFyVUY7wCuPJJC7QOd6Aa4c8ZGjl6fJtKelcS 8XViEY7UoTcKoLhOG8ha5H4ebq/rj/6vA8k03uyp/9beMrt6OcK+RFY5+fYXTOxp8+5zPk dNqZr62L7G9VKFLm81KKGIDkjm0NdjRUV0k0Kj+GfpAIYnAnxGwPf2fJ9xDXx3lstQ86Mn 1P3lsZVrSy/wRkewtUe7ki+0ZhHU8MkkdF9kXMHxo6it1o2fni9KgvR2+1dCSQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1620224632; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uqMX/kcgxstoPmvY8Wd/zciVA9qFnbv7Kyz4Ssl4A3I=; b=NLPrA9n0vhFqdef38DyhJqDycsiHukl0bJ1bmOq18k3B4jnmKVYN9rHGW0uCCIAnbFOIgb ZvE6N0pDbcaxsfBg== To: Peter Zijlstra , =?utf-8?Q?Andr=C3=A9?= Almeida Cc: Ingo Molnar , Darren Hart , linux-kernel@vger.kernel.org, Steven Rostedt , Sebastian Andrzej Siewior , kernel@collabora.com, krisman@collabora.com, pgriffais@valvesoftware.com, z.figura12@gmail.com, joel@joelfernandes.org, malteskarupke@fastmail.fm, linux-api@vger.kernel.org, fweimer@redhat.com, libc-alpha@sourceware.org, linux-kselftest@vger.kernel.org, shuah@kernel.org, acme@kernel.org, corbet@lwn.net, Peter Oskolkov Subject: Re: [PATCH v3 00/13] Add futex2 syscalls In-Reply-To: References: <20210427231248.220501-1-andrealmeid@collabora.com> Date: Wed, 05 May 2021 16:23:52 +0200 Message-ID: <87bl9pi7if.ffs@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Wed, May 05 2021 at 14:31, Peter Zijlstra wrote: > On Tue, Apr 27, 2021 at 08:12:35PM -0300, Andr=C3=A9 Almeida wrote: >> Hi, >>=20 >> This patch series introduces the futex2 syscalls. > > I still utterly detest that this adds a second hash-table for no > descernable reason. > > The new syscall interface does not depend on that in any way, you > previously implemented the multi-wait thing in the current futex code. > > Like I said last time; I'm okay with the new interface, but I don't see > why you need to reimplement the insides, that's all pointless code > duplication. The real question is whether we really need to model all of this along the existing futex functionality. I wouldn't mind a new infrastructure which addresses all the other known issues of futexes and makes the overall design less horrible than what we have now. But that needs input from futex users (libraries and other horrible wrappers) to figure out what they really need, hate, like or do not care about. Without that we are bound to pile more crap on the existing pile of horrors forever. Thanks, tglx