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, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED autolearn=ham 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 9053BC5CFC1 for ; Fri, 15 Jun 2018 17:50:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F1BF9208B8 for ; Fri, 15 Jun 2018 17:50:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="QHx/biTE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F1BF9208B8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=efficios.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936365AbeFORuU (ORCPT ); Fri, 15 Jun 2018 13:50:20 -0400 Received: from mail.efficios.com ([167.114.142.138]:50294 "EHLO mail.efficios.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932194AbeFORuS (ORCPT ); Fri, 15 Jun 2018 13:50:18 -0400 Received: from localhost (ip6-localhost [IPv6:::1]) by mail.efficios.com (Postfix) with ESMTP id 46AED22B6BD; Fri, 15 Jun 2018 13:50:18 -0400 (EDT) Received: from mail.efficios.com ([IPv6:::1]) by localhost (mail02.efficios.com [IPv6:::1]) (amavisd-new, port 10032) with ESMTP id IlI_9IyM5Puz; Fri, 15 Jun 2018 13:50:17 -0400 (EDT) Received: from localhost (ip6-localhost [IPv6:::1]) by mail.efficios.com (Postfix) with ESMTP id D91ED22B6BA; Fri, 15 Jun 2018 13:50:17 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.10.3 mail.efficios.com D91ED22B6BA DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=default; t=1529085017; bh=ugdPHqB4NyO3WnoOGIXshz4+Q97pPFWbQNxYdkNKtao=; h=Date:From:To:Message-ID:MIME-Version; b=QHx/biTEhrn4xilx6asQ3jJvfGiak5RsmmLpYTS2XaawS4AfraqsvB1dNjYMuquUs hVNFfw2DfyWyXBRy7lClHPnEzrTD7atA+xB5GU66enCwKTRBZnsLD7K8HWiyxh7Il0 MT0qnPlbP6atjPO4LFYUo/WVfrdbAnvU1Wz4da1xtpcE9kO778eg8OxL2R83PstdXY pVYZC2WLc+3KH9f9T4TWN5ZF06D2AK50VsyBDU8Pa08054dbWN4VFcS+rmMCjt81et 8lRckuQEX5Lm6U3u6LeChHNlPI+Vp0SxhmaO97eecSs1vEUPtjw1QeUH0YY0VtVBbn 0aIifCLRv62Tg== X-Virus-Scanned: amavisd-new at efficios.com Received: from mail.efficios.com ([IPv6:::1]) by localhost (mail02.efficios.com [IPv6:::1]) (amavisd-new, port 10026) with ESMTP id TZlTSmDtuOgA; Fri, 15 Jun 2018 13:50:17 -0400 (EDT) Received: from mail02.efficios.com (mail02.efficios.com [167.114.142.138]) by mail.efficios.com (Postfix) with ESMTP id C441D22B6B3; Fri, 15 Jun 2018 13:50:17 -0400 (EDT) Date: Fri, 15 Jun 2018 13:50:17 -0400 (EDT) From: Mathieu Desnoyers To: Florian Weimer Cc: Pavel Machek , carlos , Peter Zijlstra , "Paul E. McKenney" , Boqun Feng , Thomas Gleixner , linux-kernel , libc-alpha Message-ID: <422468177.14427.1529085017684.JavaMail.zimbra@efficios.com> In-Reply-To: References: <1084280721.10859.1528746558696.JavaMail.zimbra@efficios.com> <31fc101a-295b-067b-1a82-7e9e509fc92f@redhat.com> <305409897.10888.1528747473727.JavaMail.zimbra@efficios.com> <091061df-3482-8762-30e4-feaf3417be11@redhat.com> <417742741.11550.1528821084084.JavaMail.zimbra@efficios.com> <20180614122759.GB8798@amd> <894222691.12973.1528981314012.JavaMail.zimbra@efficios.com> Subject: Re: Restartable Sequences system call merged into Linux MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [167.114.142.138] X-Mailer: Zimbra 8.8.8_GA_2096 (ZimbraWebClient - FF52 (Linux)/8.8.8_GA_1703) Thread-Topic: Restartable Sequences system call merged into Linux Thread-Index: FxHJxO2X/PkHE33fjREx7yFbJyZx8w== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ----- On Jun 15, 2018, at 1:09 AM, Florian Weimer fweimer@redhat.com wrote: > On 06/14/2018 03:01 PM, Mathieu Desnoyers wrote: >> Another alternative would be to somehow let glibc handle the registration, >> perhaps only doing it for applications expressing their interest for rseq. > > That's not really possible. We can't rely on the visibility of symbol > bindings due to lazy binding and hidden visibility. Registration of > intent by other means will not work because if it is done from user > code, some other library may have already launched a thread at this point. > > (It's also a moot point if we want to use restartable sequences in glibc > itself.) Considering that we can expect the glibc memory allocator to benefit from rseq to speed up its memory allocator, this means pretty much any application linked against glibc *will* end up using rseq indirectly. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com