From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f69.google.com (mail-wm0-f69.google.com [74.125.82.69]) by kanga.kvack.org (Postfix) with ESMTP id E478C6B0033 for ; Tue, 7 Feb 2017 16:06:59 -0500 (EST) Received: by mail-wm0-f69.google.com with SMTP id t18so27660793wmt.7 for ; Tue, 07 Feb 2017 13:06:59 -0800 (PST) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id n14si453148wmd.11.2017.02.07.13.06.58 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 07 Feb 2017 13:06:58 -0800 (PST) Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v17L3rcA139112 for ; Tue, 7 Feb 2017 16:06:57 -0500 Received: from e37.co.us.ibm.com (e37.co.us.ibm.com [32.97.110.158]) by mx0b-001b2d01.pphosted.com with ESMTP id 28fmmd31pq-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 07 Feb 2017 16:06:57 -0500 Received: from localhost by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 7 Feb 2017 14:06:55 -0700 Date: Tue, 7 Feb 2017 13:06:51 -0800 From: "Paul E. McKenney" Subject: Re: PCID review? Reply-To: paulmck@linux.vnet.ibm.com References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Message-Id: <20170207210651.GB30506@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andy Lutomirski Cc: Borislav Petkov , Kees Cook , Dave Hansen , "linux-mm@kvack.org" On Tue, Feb 07, 2017 at 10:56:59AM -0800, Andy Lutomirski wrote: > Quite a few people have expressed interest in enabling PCID on (x86) > Linux. Here's the code: > > https://git.kernel.org/cgit/linux/kernel/git/luto/linux.git/log/?h=x86/pcid > > The main hold-up is that the code needs to be reviewed very carefully. > It's quite subtle. In particular, "x86/mm: Try to preserve old TLB > entries using PCID" ought to be looked at carefully to make sure the > locking is right, but there are plenty of other ways this this could > all break. > > Anyone want to take a look or maybe scare up some other reviewers? > (Kees, you seemed *really* excited about getting this in.) Cool! So I can drop 61ec4c556b0d "rcu: Maintain special bits at bottom of ->dynticks counter", correct? Thanx, Paul -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org