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=-1.1 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 6CC24C10F0E for ; Thu, 18 Apr 2019 15:45:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3D464217FA for ; Thu, 18 Apr 2019 15:45:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="doiaRa7l" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389498AbfDRPp2 (ORCPT ); Thu, 18 Apr 2019 11:45:28 -0400 Received: from mail.efficios.com ([167.114.142.138]:34824 "EHLO mail.efficios.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731317AbfDRPp1 (ORCPT ); Thu, 18 Apr 2019 11:45:27 -0400 Received: from localhost (ip6-localhost [IPv6:::1]) by mail.efficios.com (Postfix) with ESMTP id 542F618CBD1; Thu, 18 Apr 2019 11:45:26 -0400 (EDT) Received: from mail.efficios.com ([IPv6:::1]) by localhost (mail02.efficios.com [IPv6:::1]) (amavisd-new, port 10032) with ESMTP id q3A5jv81wklf; Thu, 18 Apr 2019 11:45:26 -0400 (EDT) Received: from localhost (ip6-localhost [IPv6:::1]) by mail.efficios.com (Postfix) with ESMTP id DD59C18CBC8; Thu, 18 Apr 2019 11:45:25 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.10.3 mail.efficios.com DD59C18CBC8 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=default; t=1555602325; bh=wx+d4/Ew5sWNE1k2M00jLFmc9PiB+/rIg9xnPzz/IMI=; h=Date:From:To:Message-ID:MIME-Version; b=doiaRa7lGOlMoBIb2023XLzd4SSGYmUoP50joquWJyeCrukMhPA9+Dq8Ft4r/GtO0 ETQzGZllBargISDcun/AeOWfqPsDuU3NVFJfwlV2kE7yY+7ACNRoUt+HwOH3u9CZnZ RvaaPPb+kv5RHHNKk1dE8ACdg6h6K/fTScBnDu/Wti+6I6WqC4iWMhdd/rN720lIx0 TrUPtv81QZDB4NzRD/DDFaEqvujUNHv9qfa85TheFZD7FzjxZITzAsJFq7oruRCyPk PDtmOkO3shg3FmcNidBsmQoL2HGDNBFGsqA3NHcKywUGn3y98PPXRw/oUzUJlBV5to zayKudIHJhugA== 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 6nM6zsHsJ73F; Thu, 18 Apr 2019 11:45:25 -0400 (EDT) Received: from mail02.efficios.com (mail02.efficios.com [167.114.142.138]) by mail.efficios.com (Postfix) with ESMTP id C51E218CBC1; Thu, 18 Apr 2019 11:45:25 -0400 (EDT) Date: Thu, 18 Apr 2019 11:45:25 -0400 (EDT) From: Mathieu Desnoyers To: Szabolcs Nagy Cc: carlos , nd , Florian Weimer , Joseph Myers , libc-alpha , Thomas Gleixner , Ben Maurer , Peter Zijlstra , "Paul E. McKenney" , Boqun Feng , Will Deacon , Dave Watson , Paul Turner , linux-kernel , linux-api Message-ID: <1072203859.1074.1555602325772.JavaMail.zimbra@efficios.com> In-Reply-To: References: <20190416173216.9028-1-mathieu.desnoyers@efficios.com> <20190416173216.9028-3-mathieu.desnoyers@efficios.com> Subject: Re: [PATCH 2/5] glibc: sched_getcpu(): use rseq cpu_id TLS on Linux (v2) 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 8.8.12_GA_3794 (ZimbraWebClient - FF66 (Linux)/8.8.12_GA_3794) Thread-Topic: glibc: sched_getcpu(): use rseq cpu_id TLS on Linux (v2) Thread-Index: AQHU9HpZl2rnFP3D20yib30BAxg97aZCDzCAXM98Qgw= Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ----- On Apr 18, 2019, at 11:33 AM, Szabolcs Nagy Szabolcs.Nagy@arm.com wrote: > On 16/04/2019 18:32, Mathieu Desnoyers wrote: >> --- a/sysdeps/unix/sysv/linux/sched_getcpu.c >> +++ b/sysdeps/unix/sysv/linux/sched_getcpu.c >> @@ -37,3 +37,26 @@ sched_getcpu (void) >> return -1; >> #endif >> } >> + >> +#ifdef __NR_rseq >> +#include >> +#endif >> + >> +#if defined __NR_rseq && defined RSEQ_SIG >> +extern __attribute__ ((tls_model ("initial-exec"))) >> +__thread volatile struct rseq __rseq_abi; > > i'd expect sys/rseq.h to provide this declaration. And it actually does! Will remove this duplicate. Thanks, Mathieu > >> + >> +int >> +sched_getcpu (void) >> +{ >> + int cpu_id = __rseq_abi.cpu_id; >> + >> + return cpu_id >= 0 ? cpu_id : vsyscall_sched_getcpu (); >> +} >> +#else >> +int >> +sched_getcpu (void) >> +{ >> + return vsyscall_sched_getcpu (); >> +} >> +#endif >> -- 2.17.1 -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com