From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS3215 2.6.0.0/16 X-Spam-Status: No, score=-4.2 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server2.sourceware.org [IPv6:2620:52:3:1:0:246e:9693:128c]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 8C9121F5AE for ; Wed, 5 May 2021 14:23:56 +0000 (UTC) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id BFFB3384F02C; Wed, 5 May 2021 14:23:55 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org BFFB3384F02C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1620224635; bh=uqMX/kcgxstoPmvY8Wd/zciVA9qFnbv7Kyz4Ssl4A3I=; h=To:Subject:In-Reply-To:References:Date:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=eK+LcsTVPpuWv6+7uxfxYt7ycTnJRQpujFGfScfTYArh72oj9v64NBb/l9bqpqMk+ NCxVpzSbbqKhJxnS6b8utxHTywvLWW6mmdkLhRqI/IZH0L58S513c7IHvAsD1mFBKW VMtZ5wHo0XcVD/Gj9RBcaBR/wnN6vv3GBso0uPOw= Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by sourceware.org (Postfix) with ESMTPS id D6D333851C2F for ; Wed, 5 May 2021 14:23:53 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org D6D333851C2F To: Peter Zijlstra , =?utf-8?Q?Andr=C3=A9?= Almeida 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 X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Thomas Gleixner via Libc-alpha Reply-To: Thomas Gleixner Cc: fweimer@redhat.com, shuah@kernel.org, libc-alpha@sourceware.org, corbet@lwn.net, linux-api@vger.kernel.org, Sebastian Andrzej Siewior , linux-kernel@vger.kernel.org, Steven Rostedt , Peter Oskolkov , Ingo Molnar , malteskarupke@fastmail.fm, linux-kselftest@vger.kernel.org, joel@joelfernandes.org, Darren Hart , acme@kernel.org, kernel@collabora.com, krisman@collabora.com, z.figura12@gmail.com, pgriffais@valvesoftware.com Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" 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