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 DDE62C433ED for ; Wed, 5 May 2021 13:51:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A05A2613AA for ; Wed, 5 May 2021 13:51:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233094AbhEENwV (ORCPT ); Wed, 5 May 2021 09:52:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57682 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232967AbhEENwU (ORCPT ); Wed, 5 May 2021 09:52:20 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C3E29C061574 for ; Wed, 5 May 2021 06:51:23 -0700 (PDT) From: Kurt Kanzenbach DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1620222680; 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: in-reply-to:in-reply-to:references:references; bh=g/GpEF2bVEbo7bj/SJzowkKdzRgfe0IpPQJ2B862nEM=; b=Sdfnx0qT+frgFt3WojN//pyQPVdFA4i/5lN60UIdfGxKractshbvX5Xf6G9VxUplYoYZGu 0oQ11vlS9ESYe9buWyHgqV5v4KK1zQknLDlOWitgOwktMF7SYJ8jQreHdY8qqRwRbNwSkD qRBEPAMp580HZGGXG9da8dSWczi0WOzyKLja8BJIvC8pwTS02lFu1rI0y+ep8l6pSXwaCb RgW47UFQSwQdHgMN+Onmmibz1SSEED2SYJnMDQZRcc99zaCDsQfwQinh0Gb1/xog3G4ifC 3rT0TLx3kI78bVBnS/evqS+OU4QrZA1rtRssCJ0i30QGwS4cQs6DySHZjqgJoA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1620222680; 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: in-reply-to:in-reply-to:references:references; bh=g/GpEF2bVEbo7bj/SJzowkKdzRgfe0IpPQJ2B862nEM=; b=+KZbvEO3QELFUwQ3py8+7t1a1IcV7Q+x27LyH9iEk9yWnZbUx5/os5+Sny7RRwAby3umCx akxCwAzjh7kdsVCQ== To: Peter Zijlstra , Thomas Gleixner Cc: LKML , Adhemerval Zanella , Lukasz Majewski , Florian Weimer , Carlos O'Donell , "Michael Kerrisk (man-pages)" , Davidlohr Bueso , Ingo Molnar , Darren Hart , Andrei Vagin Subject: Re: [patch 0/6] futex: Bugfixes and FUTEX_LOCK_PI2 In-Reply-To: References: <20210422194417.866740847@linutronix.de> Date: Wed, 05 May 2021 15:51:18 +0200 Message-ID: <87r1ilp9ux.fsf@kurt> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-=-= Content-Type: text/plain On Wed May 05 2021, Peter Zijlstra wrote: > It's all somewhat sad, but I don't see any other way out of this. Using > LOCK_PI2 will be a fairly horrible pile of hacks on the userspace side > of things given they need to first detect it's presence etc., but that > seems unavoidable whatever we do :/ Well, that's the interesting point. I do have such horrible hacks for glibc, which detect the presence of LOCK_PI2 at run time. However, the glibc has also the notion of kernel features based on the Linux kernel version. Then, it could be detected at compile time. At the end of the day it depends on how this patch set is merged. I was hoping for the glibc folks to share their opinion on this :-). Thanks, Kurt --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQJHBAEBCgAxFiEEooWgvezyxHPhdEojeSpbgcuY8KYFAmCSotYTHGt1cnRAbGlu dXRyb25peC5kZQAKCRB5KluBy5jwpkMYD/9qkV+sIhhArxSY4O1HZ+J+Ee80F5JB HMPssquvl7wr7a3ghR5ri0xo0/3OkVoK4n7bJ6nr1I0aECvqfEz5ha319rbLtxgV 2MMu7OLJYKZY5Mnf3pXFwMOst4Vr8aSb31vAxccSLFttTMaq6RajsaMzl9Be33WH yjv/qANort61mNn1VwjX89kzi/5joDItkGUenp3XDf1sj4yDZpXaXE2fULfakCV3 zyBiLMtboEyybyTxNzi3vo93bte4KCa68gq3F8YAac03eXXR4qy22pAQnodz1nQt jNgMu29MgYoms0HmoOYZf2rRZRjaxVJyWINdcGYbSLUt2fmwlY542Dspk+Of7SDa 6SvqvLERk959fZSxl7NLl0YauNKatmif5uaj6ILzaPxqIuoqXLUOar/g99xNqZ9g ENABEZI4FBMcamXI4MIOOdpqiTVJYJhAdO5q9CXfZxAolulWU8wMS0FeFGnY17FZ T1x9i+Pmr7uFugIQCq1Wglgya/58YaO3DzmtDxZo01pN2bEk3x1lWWvDaGZSQHXd X2EvzVb8yHpBCnpFtl7SM9ACq5onEKaKiGBRC5t+CcPJzlO9D8E30sLfD2cWNCgy dC78eO+AN5VSLfDqw8BgDf8Z7y9dql3SWcECeluYziQ7I7+UxhXvmKAWslvRd5om KfzStgm74Vc8tA== =Lpy5 -----END PGP SIGNATURE----- --=-=-=--