Received: by 10.223.176.5 with SMTP id f5csp478571wra; Tue, 30 Jan 2018 14:44:25 -0800 (PST) X-Google-Smtp-Source: AH8x2273WM6nSfiy/VzkluoPeJDcGOwClKH0Mn3bvwLu8bjLatihiKtgEhClcquNmjWhHAJ+IFTP X-Received: by 2002:a17:902:5305:: with SMTP id b5-v6mr12820015pli.61.1517352265852; Tue, 30 Jan 2018 14:44:25 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1517352265; cv=none; d=google.com; s=arc-20160816; b=yYvHpbDPPki52AF2UPpMnTrBvqMGdBCGL/B/arCi4HMJwk8LxU4JRyPA7rRa1TGqwx qYBMKGBrWmrSEDvSmV+lg6RddwkJfRwe4Nq240/X3+KZh6G51B98YYVbxutf5hEHeKJp 2NcyNwBFWAtPSlHAWX3lz6iZy/c/FsMlxVGQ9LLK+G5HzWPdo5IZtL3Du4ZWN6ZjA0Et RvRyJtHWJJ6iMA7Ii1sbf8aFMjfBxmZeKmy121qCDxBydYTCRSUVLijSqJDoy1TQpFpA EAdAZQDa52BE4Pt4brAIYxvc+kWpriEaCSZY79aOJxdtjzh4aC98ubQlExej9wTZx9jG ghxQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:arc-authentication-results; bh=q5otL1bBbm18ht3nxDkEBA1Y+zzvUN+uDThmZosnJy0=; b=Fehe6GkCCHhzdzDkbgNYvgTK/szGN5oTTkGYtgrq9M8y0Tyu0SHKVNdBeVYyKj1T9W DspppbeeU4xiVhTS738o/OYcnPf5wrhDOV8szNo3ChD13ikdzdW2QxyQi6x7KxvomyJ7 BrVT9qx0Ava6rRufXIms5XCVWL9CW39hLy1A7xcpbvrdY1VUEww+PTw9bMVmY3XLsxt2 Gd+0jfmgXpQZwFsm98S1xeMjTU+J5TcIDI9IAUQNz+XZ5CM994IQs9Jq1v20/bK5+H94 +ZC2QnX6gfHHspoedwjOgsaLG4wztHDOjA0BlsnS16TUH1qSXbkBcXG33jHu37ovsJeb CXow== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id h9-v6si50135pls.224.2018.01.30.14.44.12; Tue, 30 Jan 2018 14:44:25 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753371AbeA3Wnu (ORCPT + 99 others); Tue, 30 Jan 2018 17:43:50 -0500 Received: from mail.skyhub.de ([5.9.137.197]:52042 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753009AbeA3Wnt (ORCPT ); Tue, 30 Jan 2018 17:43:49 -0500 X-Virus-Scanned: Nedap ESD1 at mail.skyhub.de Received: from mail.skyhub.de ([127.0.0.1]) by localhost (blast.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id DeZvegeeswUd; Tue, 30 Jan 2018 23:43:47 +0100 (CET) Received: from pd.tnic (p200300EC2BCF0F005D4DFBFD0E3B986B.dip0.t-ipconnect.de [IPv6:2003:ec:2bcf:f00:5d4d:fbfd:e3b:986b]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id BA49E1EC0270; Tue, 30 Jan 2018 23:43:47 +0100 (CET) Date: Tue, 30 Jan 2018 23:43:40 +0100 From: Borislav Petkov To: Tim Chen Cc: David Woodhouse , arjan@linux.intel.com, tglx@linutronix.de, karahmed@amazon.de, x86@kernel.org, linux-kernel@vger.kernel.org, peterz@infradead.org, pbonzini@redhat.com, ak@linux.intel.com, torvalds@linux-foundation.org, gregkh@linux-foundation.org, mingo@kernel.org, luto@kernel.org, linux@dominikbrodowski.net Subject: Re: [PATCH] x86/speculation: Use Indirect Branch Prediction Barrier in context switch Message-ID: <20180130224340.2zdfqttupugtqww5@pd.tnic> References: <1517263487-3708-1-git-send-email-dwmw@amazon.co.uk> <20180130203836.bsgme6kf6hstgbrx@pd.tnic> <024dd53b-1912-34fa-deb8-550c111df521@linux.intel.com> <20180130215731.pszc5u4gcc32ds4v@pd.tnic> <296de30b-515b-6eab-1b13-bb2f71451004@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <296de30b-515b-6eab-1b13-bb2f71451004@linux.intel.com> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 30, 2018 at 02:26:53PM -0800, Tim Chen wrote: > If the process has multiple threads running on different cpus, I'm talking about issuing the barrier in set_dumpable(). What threads on multiple CPUs? -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.