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 mtagate4.de.ibm.com (8.12.10/8.12.10) with ESMTP id j8TDEdO0184756 for ; Thu, 29 Sep 2005 13:14:39 GMT Received: from d12av02.megacenter.de.ibm.com (d12av02.megacenter.de.ibm.com [9.149.165.228]) by d12nrmr1607.megacenter.de.ibm.com (8.12.10/NCO/VERS6.7) with ESMTP id j8TDEd9P116626 for ; Thu, 29 Sep 2005 15:14:39 +0200 Received: from d12av02.megacenter.de.ibm.com (loopback [127.0.0.1]) by d12av02.megacenter.de.ibm.com (8.12.11/8.13.3) with ESMTP id j8TDEd7C004251 for ; Thu, 29 Sep 2005 15:14:39 +0200 Date: Thu, 29 Sep 2005 15:14:49 +0200 From: Martin Schwidefsky Subject: [RFC] Guest page hinting patches. Message-ID: <20050929131449.GA5700@skybase.boeblingen.de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: owner-linux-mm@kvack.org Return-Path: To: linux-mm@kvack.org Cc: frankeh@watson.ibm.com, rhim@cc.gatech.edu List-ID: Hi folks, the guest page hinting code I was talking about on the OLS finally runs stable on our test system so I created a first set of patches for review. There are 6 patches against 2.6.13 (yes I know I need to upgrade to something more recent). I tried to split the patches into meaningful parts to reduce the complexity of the whole thing a bit. The patches: 1) Base patch. Introduces most of the common code. It adds two new page flags for serializing page state changes and to identify discarded pages. I would like to avoid adding page flags but failed to see a different solution in both cases. Another point of discussion would be the page->mapping/__remove_from_page_cache hack. 2) Mlock and friends. Adds special handling for mlocked pages. I use a field in the struct address_space to identify mlocked pages. Any betters ideas? 3) Support writable ptes. Adds another page flag (this makes 3 new page flags in total ..) 4) Minor fault vs. page state changes. 5) Discarded page list. Ugly problem of virtual vs. absolute addresses on the discard fault. We tried talking the s390 architecture folks into providing virtual guest addresses but it seems that this is not possible with the current hardware. 6) s390 guest support for guest page hinting. The patches do not include support for the host side of the equation. For s390 this is implemented in the z/VM hypervisor. So, what do you think? blue skies, Martin. -- 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