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Re: [PATCH v2 00/10] PCID and improved laziness

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On Wed, Jun 14, 2017 at 3:18 PM, Dave Hansen <dave.hansen@intel.com> wrote:
> On 06/13/2017 09:56 PM, Andy Lutomirski wrote:
>> 2. Mms that have been used recently on a given CPU might get to keep
>>    their TLB entries alive across process switches with this patch
>>    set.  TLB fills are pretty fast on modern CPUs, but they're even
>>    faster when they don't happen.
>
> Let's not forget that TLBs are also getting bigger.  The bigger TLBs
> help ensure that they *can* survive across another process's timeslice.
>
> Also, the cost to refill the paging structure caches is going up.  Just
> think of how many cachelines you have to pull in to populate a
> ~1500-entry TLB, even if the CPU hid the latency of those loads.

Then throw EPT into the mix for extra fun.  I wonder if we should try
to allocate page tables from nearby physical addresses if we think we
might be running as a guest.

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[PATCH v2 00/10] PCID and improved laziness Andy Lutomirski <luto@kernel.org> - 2017-06-14 07:00 +0200
  [PATCH v2 09/10] x86/mm: Enable CR4.PCIDE on supported systems Andy Lutomirski <luto@kernel.org> - 2017-06-14 07:00 +0200
    Re: [PATCH v2 09/10] x86/mm: Enable CR4.PCIDE on supported systems Juergen Gross <jgross@suse.com> - 2017-06-14 07:40 +0200
  [PATCH v2 06/10] x86/mm: Stop calling leave_mm() in idle code Andy Lutomirski <luto@kernel.org> - 2017-06-14 07:00 +0200
  [PATCH v2 04/10] x86/mm: Track the TLB's tlb_gen and update the flushing algorithm Andy Lutomirski <luto@kernel.org> - 2017-06-14 07:00 +0200
  [PATCH v2 02/10] x86/mm: Remove reset_lazy_tlbstate() Andy Lutomirski <luto@kernel.org> - 2017-06-14 07:00 +0200
    Re: [PATCH v2 02/10] x86/mm: Remove reset_lazy_tlbstate() Rik van Riel <riel@redhat.com> - 2017-06-15 21:30 +0200
  [PATCH v2 10/10] x86/mm: Try to preserve old TLB entries using PCID Andy Lutomirski <luto@kernel.org> - 2017-06-14 07:00 +0200
    Re: [PATCH v2 10/10] x86/mm: Try to preserve old TLB entries using  PCID Nadav Amit <nadav.amit@gmail.com> - 2017-06-18 08:30 +0200
      Re: [PATCH v2 10/10] x86/mm: Try to preserve old TLB entries using PCID Andy Lutomirski <luto@kernel.org> - 2017-06-20 00:10 +0200
  Re: [PATCH v2 00/10] PCID and improved laziness Dave Hansen <dave.hansen@intel.com> - 2017-06-15 00:20 +0200
    Re: [PATCH v2 00/10] PCID and improved laziness Andy Lutomirski <luto@kernel.org> - 2017-06-15 00:50 +0200
  Re: [PATCH v2 00/10] PCID and improved laziness "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-06-18 23:40 +0200
    Re: [PATCH v2 00/10] PCID and improved laziness Andy Lutomirski <luto@kernel.org> - 2017-06-19 06:50 +0200

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