On Mon, Jan 20, 2014 at 03:48:36PM +0100, Alexander Graf wrote: > > On 15.01.2014, at 07:36, Liu ping fan <kernelfans@xxxxxxxxx> wrote: > > > On Thu, Jan 9, 2014 at 8:08 PM, Alexander Graf <agraf@xxxxxxx> wrote: > >> > >> On 11.12.2013, at 09:47, Liu Ping Fan <kernelfans@xxxxxxxxx> wrote: > >> > >>> This series is based on Aneesh's series "[PATCH -V2 0/5] powerpc: mm: Numa faults support for ppc64" > >>> > >>> For this series, I apply the same idea from the previous thread "[PATCH 0/3] optimize for powerpc _PAGE_NUMA" > >>> (for which, I still try to get a machine to show nums) > >>> > >>> But for this series, I think that I have a good justification -- the fact of heavy cost when switching context between guest and host, > >>> which is well known. > >> > >> This cover letter isn't really telling me anything. Please put a proper description of what you're trying to achieve, why you're trying to achieve what you're trying and convince your readers that it's a good idea to do it the way you do it. > >> > > Sorry for the unclear message. After introducing the _PAGE_NUMA, > > kvmppc_do_h_enter() can not fill up the hpte for guest. Instead, it > > should rely on host's kvmppc_book3s_hv_page_fault() to call > > do_numa_page() to do the numa fault check. This incurs the overhead > > when exiting from rmode to vmode. My idea is that in > > kvmppc_do_h_enter(), we do a quick check, if the page is right placed, > > there is no need to exit to vmode (i.e saving htab, slab switching) > > > >>> If my suppose is correct, will CCing kvm@xxxxxxxxxxxxxxx from next version. > >> > >> This translates to me as "This is an RFC"? > >> > > Yes, I am not quite sure about it. I have no bare-metal to verify it. > > So I hope at least, from the theory, it is correct. > > Paul, could you please give this some thought and maybe benchmark it? OK, once I get Aneesh to tell me how I get to have ptes with _PAGE_NUMA set in the first place. :) Paul. -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
