Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752120AbaL2MNY (ORCPT ); Mon, 29 Dec 2014 07:13:24 -0500 Received: from cantor2.suse.de ([195.135.220.15]:36762 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751435AbaL2MNW (ORCPT ); Mon, 29 Dec 2014 07:13:22 -0500 Date: Mon, 29 Dec 2014 13:13:17 +0100 (CET) From: Jiri Kosina X-X-Sender: jikos@twin.jikos.cz To: Pavel Machek cc: Andy Lutomirski , kernel list , yoongukim@cmu.edu, donghyu1@cmu.edu, omutlu@gmail.com Subject: Re: DRAM unreliable under specific access patern In-Reply-To: <20141224175040.GA28791@amd> Message-ID: References: <20141224163823.GA17035@amd> <20141224172506.GA23683@amd> <20141224175040.GA28791@amd> User-Agent: Alpine 2.00 (LRH 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 24 Dec 2014, Pavel Machek wrote: > Well... We could periodically scrub (every few miliseconds) pages > mapped to userspace. I.e. implement ECC in software. Would be extremely slow though. > We might be able to do some magic and disallow cache flushes to > userspace programs. My understanding is that cflush is not strictly necessary, it only makes the issue more likely to trigger. If you modify the pattern so that it neraly fits into cacheline (but not really), you would be able to produce similar (if not the same) cache eviction pattern as if without explicit cflush. Right? -- Jiri Kosina SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/