From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d12nrmr1607.megacenter.de.ibm.com (d12nrmr1607.megacenter.de.ibm.com [9.149.167.49]) by mtagate5.de.ibm.com (8.13.8/8.13.8) with ESMTP id m8QAhEWg083172 for ; Fri, 26 Sep 2008 10:43:14 GMT Received: from d12av02.megacenter.de.ibm.com (d12av02.megacenter.de.ibm.com [9.149.165.228]) by d12nrmr1607.megacenter.de.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id m8QAhE0l3387602 for ; Fri, 26 Sep 2008 12:43:14 +0200 Received: from d12av02.megacenter.de.ibm.com (loopback [127.0.0.1]) by d12av02.megacenter.de.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m8QAhEpd001799 for ; Fri, 26 Sep 2008 12:43:14 +0200 Subject: Re: Populating multiple ptes at fault time From: Martin Schwidefsky Reply-To: schwidefsky@de.ibm.com In-Reply-To: <48DBD94A.50905@goop.org> References: <48D142B2.3040607@goop.org> <48D17E75.80807@redhat.com> <48D1851B.70703@goop.org> <48D18919.9060808@redhat.com> <48D18C6B.5010407@goop.org> <48D2B970.7040903@redhat.com> <48D2D3B2.10503@goop.org> <48D2E65A.6020004@redhat.com> <48D2EBBB.205@goop.org> <48D2F05C.4040000@redhat.com> <48D2F571.4010504@goop.org> <48DA333C.2050900@redhat.com> <48DBD94A.50905@goop.org> Content-Type: text/plain Date: Fri, 26 Sep 2008 12:26:27 +0200 Message-Id: <1222424787.22679.17.camel@localhost> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Jeremy Fitzhardinge Cc: Avi Kivity , Nick Piggin , Hugh Dickens , Linux Memory Management List , Linux Kernel Mailing List , Andrew Morton , Rik van Riel , Marcelo Tosatti , Benjamin Herrenschmidt List-ID: On Thu, 2008-09-25 at 11:32 -0700, Jeremy Fitzhardinge wrote: > Very few places actually care about the state of the A/D bits; would it > be expensive to make those places explicitly ask for synchronization > before testing the bits (or alternatively, have an explicit query > operation rather than just poking about in the ptes). Martin, does this > help with s390's per-page (vs per-pte) A/D state? With the kvm support the situation on s390 recently has grown a tad more complicated. We now have dirty bits in the per-page storage key and in the pgste (page table entry extension) for the kvm guests. For the A/D bits in the storage key the new pte operations won't help, for the kvm related bits they could make a difference. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. -- 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