Avi Kivity wrote: > Andrea Arcangeli wrote: >> On Wed, Apr 02, 2008 at 12:50:50PM +0300, Avi Kivity wrote: >> >>> Isn't it faster though? We don't need to pull in the cacheline >>> containing the struct page anymore. >>> >> >> Exactly, not only that, get_user_pages is likely a bit slower that we >> need for just kvm pte lookup. GRU uses follow_page directly because it >> runs in the tlb miss handler, for us instead the tlb miss handler >> doesn't invoke a page fault unless the spte is non present. >> >> > > How about this plan? > > 0. Merge mmu notifiers > > 1. gfn_to_page() -> gfn_to_pfn() > > Still keeping the refcount. Change bad_page to kvm_bad_hfn. > > 2. Drop the refcounting from gfn_to_pfn() and from kvm_release_page_*() > > Still using get_user_pages() (and dropping the refcount immediately) > > Simultaneously, change hack_module.awk to add the refcount back. > > 3. Export follow_page() or something based on fast_gup(), and use it > > btw, if we change the method we use to read the Linux pte, I'd like to > get the writable bit out of it. This was, when we create an spte for > a gpte that is writable and dirty, we can set the spte writable iff > the Linux pte is writable. This avoids breaking COW unnecessarily. >
Ugh, there's still mark_page_accessed() and SetPageDirty(). -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
