From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Fitzhardinge Subject: Re: [PATCH 1 of 4] mm: add a ptep_modify_prot transaction abstraction Date: Thu, 19 Jun 2008 10:57:00 -0700 Message-ID: <485A9DEC.8010406@goop.org> References: <1213831403.8011.24.camel@pasglop> <4859A149.9090004@goop.org> <4859A528.1010107@goop.org> <1213835971.8011.54.camel@pasglop> <4859E8AF.30306@goop.org> <1213860031.8011.65.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1213860031.8011.65.camel@pasglop> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: benh@kernel.crashing.org Cc: xen-devel , Peter Zijlstra , kvm-devel , x86@kernel.org, LKML , Virtualization Mailing List , Hugh Dickins , Ingo Molnar , Linus Torvalds , Thomas Gleixner List-Id: virtualization@lists.linuxfoundation.org Benjamin Herrenschmidt wrote: >> Which architecture are you interested in? If it isn't x86, you can >> probably get anything past Linus ;) >> >> I'll do some measurements to see what effect the batchable >> ptep_set_wrprotect() has on native. If it's significant, I'll propose >> making it conditional on CONFIG_PARAVIRT. >> > > Oh, I mostly think about powerpc, I just wondered if I could re-use > your new stuff in that context. Mostly idle thoughts at this stage, I > haven't looked seriously. > There are general-purpose hooks in the common code which architectures can implement however they like. In x86-land we hook them up to pvops, but you can handle them however you want. > I have an old patch set to batch forks (and mprotect etc...) TLB > invalidations (which is what I really want to batch on powerpc, more > than the actual PTE changes) that involves subtle changes to the > batching mechanisms etc... > Do you mean setting up batches of per-page tlb shootdowns rather than going a global tlb flush at the end? J