Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751659AbaK0Piu (ORCPT ); Thu, 27 Nov 2014 10:38:50 -0500 Received: from mx0.aculab.com ([213.249.233.131]:43324 "HELO mx0.aculab.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1750895AbaK0Pio (ORCPT ); Thu, 27 Nov 2014 10:38:44 -0500 From: David Laight To: "'David Hildenbrand'" , Thomas Gleixner CC: "linux-arch@vger.kernel.org" , "Michael S. Tsirkin" , Heiko Carstens , "linux-kernel@vger.kernel.org" , "Christian Borntraeger" , "paulus@samba.org" , "schwidefsky@de.ibm.com" , "akpm@linux-foundation.org" , "linuxppc-dev@lists.ozlabs.org" , "mingo@kernel.org" Subject: RE: [RFC 0/2] Reenable might_sleep() checks for might_fault() when atomic Thread-Topic: [RFC 0/2] Reenable might_sleep() checks for might_fault() when atomic Thread-Index: AQHQClV0/jzAGGN4U0aVkHiOIDETdJx0mueg Date: Thu, 27 Nov 2014 15:37:28 +0000 Message-ID: <063D6719AE5E284EB5DD2968C1650D6D1C9FDD6A@AcuExch.aculab.com> References: <20141126151729.GB9612@redhat.com> <20141126152334.GA9648@redhat.com> <20141126163207.63810fcb@thinkpad-w530> <20141126154717.GB10568@redhat.com> <5475FAB1.1000802@de.ibm.com> <20141126163216.GB10850@redhat.com> <547604FC.4030300@de.ibm.com> <20141126170447.GC11202@redhat.com> <20141127070919.GA4390@osiris> <20141127090301.3ddc3077@thinkpad-w530> <20141127120441.GB4390@osiris> <20141127161905.7c6220ee@thinkpad-w530> In-Reply-To: <20141127161905.7c6220ee@thinkpad-w530> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.202.99.200] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id sARFcvUJ025686 From: David Hildenbrand ... > Although it might not be optimal, but keeping a separate counter for > pagefault_disable() as part of the preemption counter seems to be the only > doable thing right now. I am not sure if a completely separated counter is even > possible, increasing the size of thread_info. What about adding (say) 0x10000 for the more restrictive test? David ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?