On Fri, 8 Feb 2008, Robin Holt wrote: > > > What about ib_umem_get()? > > > > Ok. It pins using an elevated refcount. Same as XPmem right now. With that > > we effectively pin a page (page migration will fail) but we will > > continually be reclaiming the page and may repeatedly try to move it. We > > have issues with XPmem causing too many pages to be pinned and thus the > > OOM getting into weird behavior modes (OOM or stop lru scanning due to > > all_reclaimable set). > > > > An elevated refcount will also not be noticed by any of the schemes under > > consideration to improve LRU scanning performance. > > Christoph, I am not sure what you are saying here. With v4 and later, > I thought we were able to use the rmap invalidation to remove the ref > count that XPMEM was holding and therefore be able to swapout. Did I miss > something? I agree the existing XPMEM does pin. I hope we are not saying > the XPMEM based upon these patches will not be able to swap/migrate.
Correct. You missed the turn of the conversation to how ib_umem_get() works. Currently it seems to pin the same way that the SLES10 XPmem works. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel