From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752733AbdLLW0J (ORCPT ); Tue, 12 Dec 2017 17:26:09 -0500 Received: from merlin.infradead.org ([205.233.59.134]:36704 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752653AbdLLW0H (ORCPT ); Tue, 12 Dec 2017 17:26:07 -0500 Date: Tue, 12 Dec 2017 23:25:16 +0100 From: Peter Zijlstra To: Thomas Gleixner Cc: Dave Hansen , Linus Torvalds , LKML , the arch/x86 maintainers , Andy Lutomirsky , Borislav Petkov , Greg KH , Kees Cook , Hugh Dickins , Brian Gerst , Josh Poimboeuf , Denys Vlasenko , Boris Ostrovsky , Juergen Gross , David Laight , Eduardo Valentin , "Liguori, Anthony" , Will Deacon , linux-mm Subject: Re: [patch 13/16] x86/ldt: Introduce LDT write fault handler Message-ID: <20171212222516.kt4xp4ec2weavbsz@hirez.programming.kicks-ass.net> References: <20171212173221.496222173@linutronix.de> <20171212173334.345422294@linutronix.de> <212680b8-6f8d-f785-42fd-61846553570d@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 12, 2017 at 10:41:03PM +0100, Thomas Gleixner wrote: > Now that made me go back to the state of the patch series which made us > make that magic 'touch' and write fault handler. The difference to the code > today is that it did not prepopulate the user visible mapping. > > We added that later because we were worried about not being able to > populate it in the #PF due to memory pressure without ripping out the magic > cure again. > > But I did now and actually removing both the user exit magic 'touch' code > and the write fault handler keeps it working. Argh, had we really not tried that!? Bah. 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 E58D26B0033 for ; Tue, 12 Dec 2017 17:25:53 -0500 (EST) Received: by mail-it0-f70.google.com with SMTP id y200so908299itc.7 for ; Tue, 12 Dec 2017 14:25:53 -0800 (PST) Received: from merlin.infradead.org (merlin.infradead.org. [2001:8b0:10b:1231::1]) by mx.google.com with ESMTPS id n83si146955ioi.76.2017.12.12.14.25.52 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 12 Dec 2017 14:25:52 -0800 (PST) Date: Tue, 12 Dec 2017 23:25:16 +0100 From: Peter Zijlstra Subject: Re: [patch 13/16] x86/ldt: Introduce LDT write fault handler Message-ID: <20171212222516.kt4xp4ec2weavbsz@hirez.programming.kicks-ass.net> References: <20171212173221.496222173@linutronix.de> <20171212173334.345422294@linutronix.de> <212680b8-6f8d-f785-42fd-61846553570d@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Thomas Gleixner Cc: Dave Hansen , Linus Torvalds , LKML , the arch/x86 maintainers , Andy Lutomirsky , Borislav Petkov , Greg KH , Kees Cook , Hugh Dickins , Brian Gerst , Josh Poimboeuf , Denys Vlasenko , Boris Ostrovsky , Juergen Gross , David Laight , Eduardo Valentin , "Liguori, Anthony" , Will Deacon , linux-mm On Tue, Dec 12, 2017 at 10:41:03PM +0100, Thomas Gleixner wrote: > Now that made me go back to the state of the patch series which made us > make that magic 'touch' and write fault handler. The difference to the code > today is that it did not prepopulate the user visible mapping. > > We added that later because we were worried about not being able to > populate it in the #PF due to memory pressure without ripping out the magic > cure again. > > But I did now and actually removing both the user exit magic 'touch' code > and the write fault handler keeps it working. Argh, had we really not tried that!? Bah. -- 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