From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: Paul Mackerras <paulus@ozlabs.org>
Cc: benh@kernel.crashing.org, mpe@ellerman.id.au,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 00/16] Remove hash page table slot tracking from linux PTE
Date: Mon, 30 Oct 2017 13:27:38 +0530 [thread overview]
Message-ID: <87wp3d130t.fsf@linux.vnet.ibm.com> (raw)
In-Reply-To: <20171027054136.GC27483@fergus.ozlabs.ibm.com>
Paul Mackerras <paulus@ozlabs.org> writes:
> On Fri, Oct 27, 2017 at 10:57:13AM +0530, Aneesh Kumar K.V wrote:
>>
>>
>> On 10/27/2017 10:04 AM, Paul Mackerras wrote:
>> >How do we interpret these numbers? Are they times, or speed? Is
>> >larger better or worse?
>>
>> Sorry for not including the details. They are time in seconds. Test case is
>> a modified mmap_bench included in powerpc/selftest.
>>
>> >
>> >Can you give us the mean and standard deviation for each set of 5
>> >please?
>> >
>>
>> powernv without patch
>> median= 51.432255
>> stdev = 0.370835
>>
>> with patch
>> median = 50.739922
>> stdev = 0.06419662
>>
>> pseries without patch
>> median = 116.617884
>> stdev = 3.04531023
>>
>> with patch no hcall
>> median = 119.42494
>> stdev = 0.85874552
>>
>> with patch and hcall
>> median = 117.735808
>> stdev = 2.7624151
>
> So on powernv, the patch set *improves* performance by about 1.3%
> (almost 2 standard deviations). Do we know why that is?
I haven't looked at that closely. I was considering it within runtime
variance (no impact with patch series). I will get perf record collected
and will see if that points to any details.
>
> On pseries, performance is about 2.4% worse without new hcalls, but
> that is less than 1 standard deviation. With new hcalls, performance
> is 0.95% worse, only a third of a standard deviation. I think we need
> to do more measurements to try to get a more accurate picture here.
>
> Were the pseries numbers done on KVM or PowerVM? Could you do a set
> of measurements on the other one too please? (I assume the numbers
> with the new hcall were done on KVM, and can't be done on PowerVM.)
>
The above pseries numbers were collected on KVM.
PowerVM numbers on a different machine:
Without patch
31.194165
31.372913
31.253494
31.416198
31.199180
MEDIAN = 31.253494
STDEV = 0.1018900
With patch series
31.538281
31.385996
31.492737
31.452514
31.259461
MEDIAN = 31.452514
STDEV = 0.108511
-aneesh
next prev parent reply other threads:[~2017-10-30 7:57 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-27 4:08 [PATCH 00/16] Remove hash page table slot tracking from linux PTE Aneesh Kumar K.V
2017-10-27 4:08 ` [PATCH 01/16] powerpc/mm/hash: Remove the superfluous bitwise operation when find hpte group Aneesh Kumar K.V
2017-10-27 4:08 ` [PATCH 02/16] powerpc/mm: Update native_hpte_find to return hash pte Aneesh Kumar K.V
2017-10-27 4:08 ` [PATCH 03/16] powerpc/pseries: Update hpte find helper to take hash value Aneesh Kumar K.V
2017-10-27 4:08 ` [PATCH 04/16] powerpc/mm: Add hash invalidate callback Aneesh Kumar K.V
2017-10-27 4:08 ` [PATCH 05/16] powerpc/mm: use hash_invalidate for __kernel_map_pages() Aneesh Kumar K.V
2017-10-27 4:08 ` [PATCH 06/16] powerpc/mm: Switch flush_hash_range to not use slot Aneesh Kumar K.V
2017-10-27 4:08 ` [PATCH 07/16] powerpc/mm: Add hash updatepp callback Aneesh Kumar K.V
2017-10-27 4:08 ` [PATCH 08/16] powerpc/mm/hash: Don't track hash pte slot number in linux page table Aneesh Kumar K.V
2017-10-27 4:08 ` [PATCH 09/16] powerpc/mm: Add new firmware feature HASH API Aneesh Kumar K.V
2017-10-27 4:08 ` [PATCH 10/16] powerpc/kvm/hash: Implement HASH_REMOVE hcall Aneesh Kumar K.V
2017-10-27 4:08 ` [PATCH 11/16] powerpc/kvm/hash: Implement HASH_PROTECT hcall Aneesh Kumar K.V
2017-10-27 4:08 ` [PATCH 12/16] powerpc/kvm/hash: Implement HASH_BULK_REMOVE hcall Aneesh Kumar K.V
2017-10-27 4:08 ` [PATCH 13/16] powerpc/mm/pseries: Use HASH_PROTECT hcall in guest Aneesh Kumar K.V
2017-10-27 4:08 ` [PATCH 14/16] powerpc/mm/pseries: Use HASH_REMOVE " Aneesh Kumar K.V
2017-10-27 4:08 ` [PATCH 15/16] powerpc/mm/pseries: Move slot based bulk remove to helper Aneesh Kumar K.V
2017-10-27 4:08 ` [PATCH 16/16] powerpc/mm/pseries: Use HASH_BULK_REMOVE hcall in guest Aneesh Kumar K.V
2017-10-27 4:34 ` [PATCH 00/16] Remove hash page table slot tracking from linux PTE Paul Mackerras
2017-10-27 5:27 ` Aneesh Kumar K.V
2017-10-27 5:41 ` Paul Mackerras
2017-10-30 7:57 ` Aneesh Kumar K.V [this message]
2017-10-30 11:49 ` Aneesh Kumar K.V
2017-10-30 13:14 ` Aneesh Kumar K.V
2017-10-30 13:49 ` Aneesh Kumar K.V
2017-11-21 8:41 ` Aneesh Kumar K.V
2017-10-28 22:35 ` Ram Pai
2017-10-29 14:05 ` Aneesh Kumar K.V
2017-10-29 22:04 ` Paul Mackerras
2017-10-30 0:51 ` Ram Pai
2017-11-01 4:46 ` Michael Ellerman
2017-11-01 11:02 ` Paul Mackerras
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