From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f70.google.com (mail-it0-f70.google.com [209.85.214.70]) by kanga.kvack.org (Postfix) with ESMTP id D4A86680FD0 for ; Tue, 14 Feb 2017 19:05:16 -0500 (EST) Received: by mail-it0-f70.google.com with SMTP id s10so51262966itb.7 for ; Tue, 14 Feb 2017 16:05:16 -0800 (PST) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id x197si1929215pgx.75.2017.02.14.16.05.15 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 14 Feb 2017 16:05:15 -0800 (PST) Date: Tue, 14 Feb 2017 16:05:14 -0800 From: Andrew Morton Subject: Re: [PATCH] mm/autonuma: don't use set_pte_at when updating protnone ptes Message-Id: <20170214160514.40765dfab42491b8b7b9bf3c@linux-foundation.org> In-Reply-To: <87a89ovp4q.fsf@skywalker.in.ibm.com> References: <1486400776-28114-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <87a89ovp4q.fsf@skywalker.in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Aneesh Kumar K.V" Cc: Rik van Riel , Mel Gorman , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Tue, 14 Feb 2017 19:41:17 +0530 "Aneesh Kumar K.V" wrote: > "Aneesh Kumar K.V" writes: > > > Architectures like ppc64, use privilege access bit to mark pte non accessible. > > This implies that kernel can do a copy_to_user to an address marked for numa fault. > > This also implies that there can be a parallel hardware update for the pte. > > set_pte_at cannot be used in such scenarios. Hence switch the pte > > update to use ptep_get_and_clear and set_pte_at combination. > > > > Signed-off-by: Aneesh Kumar K.V > > With this and other patches a kvm guest is giving me > > ... > > Reverting this patch gets rid of the above hang. But I am running into segfault > with systemd in guest. It could be some other patches in my local tree. > > Maybe we should hold merging this to 4.11 and wait for this to get more > testing ? Shall do. Please let me know the outcome... -- 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