From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-3941094-1520067308-2-453622196612083206 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.249, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='us-ascii' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1520067307; b=qHwIY7nh0faTMdW5M8NumbpQPln8ZMMgC1ctFyDOXYvQYTn cmsFXdAwvbLk0Ux/cAeQ3tEVTLg7oAktIVPgemt59M8f/IEFsZa3ZrtS1wi++088 +lbxvSQUB8R08nneSdGXpDmauEvb20fMv7CdwKuojRXiA8niynLISpTih7mk9iqM Odv2KeuiqJDfIiCdlXfR2yxNhSlA4fnsJqGvT220LOMtBEDRd3/U+2Sl1zECH6WL HYfm2emJ8xNvFqoiZKNPihU293mUoDp5/gwjZaAJoGE4Bzn7NMTMXszbstjhuSKd asJ9JbX3zmBMWSLZLktHM3zQ21KQnmvhrDdlhLA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=date:from:to:cc:subject:message-id :references:mime-version:content-type:in-reply-to:sender :list-id; s=arctest; t=1520067307; bh=BcML0Gg+sQ5DQJ53JLEkr+vM9d 0mR1FySzCU6/4ss78=; b=hyFrZYd4kqPU6aw7Q8Xv+m4MMYg2aqThx1XKRP7JZx /2OjWujtPmdpaei/8QcnB2XbMZyJ4d+Fy3HzmeLJg2j6NRbwDaXyTGG8lmWkpT/G YPHiFYjd7K25KUex31f17MgrzXBSclpRBy6q7q1pk22TsrYuPI3cUNleTLTs/8/o QnWjN9BwtruvXZju3nhtTlX/h3wvIXaL+nXwQx3twm7BsOIjMsaQc9tPC4Rdpv3x C9MqRLx0zN327lFBBSkqVDh9GLWEa5MhWBmokCFNvG9w7TDyTw/Vbskq5vTkkQMx Ou24QToNrFfyeoFR5F3hPQLP21pWaosvSX0k4Hac/ivA== ARC-Authentication-Results: i=1; mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Authentication-Results: mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751608AbeCCIy7 (ORCPT ); Sat, 3 Mar 2018 03:54:59 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:34468 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751566AbeCCIy6 (ORCPT ); Sat, 3 Mar 2018 03:54:58 -0500 Date: Sat, 3 Mar 2018 09:54:54 +0100 From: Greg Kroah-Hartman To: Tim Chen Cc: stable@vger.kernel.org, Andy Lutomirski , Nadav Amit , Thomas Gleixner , Andrew Morton , Arjan van de Ven , Borislav Petkov , Dave Hansen , Linus Torvalds , Mel Gorman , Peter Zijlstra , Rik van Riel , Ingo Molnar , David Woodhouse , ak@linux.intel.com, karahmed@amazon.de, pbonzini@redhat.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/2] Backport IBPB on context switch to non-dumpable process Message-ID: <20180303085454.GA23988@kroah.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.3 (2018-01-21) Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Fri, Mar 02, 2018 at 01:32:08PM -0800, Tim Chen wrote: > Greg, > > I will like to propose backporting "x86/speculation: Use Indirect Branch > Prediction Barrier on context switch" from commit 18bf3c3e in upstream > to 4.9 and 4.4 stable. The patch has already been ported to 4.14 and > 4.15 stable. The patch needs mm context id that Andy added in commit > f39681ed. I have lifted the mm context id change from Andy's upstream > patch and included it here. What does this patch "fix" in those older kernels? Is this a performance improvement or something else? thanks, greg k-h