On 03/26/2015 12:11 PM, J. Bruce Fields wrote:
> On Thu, Mar 26, 2015 at 11:47:03AM -0400, Anna Schumaker wrote:
>> On 03/26/2015 11:38 AM, J. Bruce Fields wrote:
>>> On Thu, Mar 26, 2015 at 11:32:25AM -0400, Trond Myklebust wrote:
>>>> On Thu, Mar 26, 2015 at 11:21 AM, Anna Schumaker
>>>> <Anna.Schumaker@xxxxxxxxxx> wrote:
>>>>> Here are my updated numbers! I tested with files 5G in size: one 100%
>>>>> data, one 100% hole, and one alternating between hole and data every 4K.
>>>>> I collected data for both v4.1 and v4.2 with and without the READ_PLUS
>>>>> patches:
>>>>>
>>>>> ##########################
>>>>> # #
>>>>> # Without READ_PLUS #
>>>>> # #
>>>>> ##########################
>>>>>
>>>>>
>>>>> NFS v4.1:
>>>>> Trial
>>>>> |---------|---------|---------|---------|---------|---------|---------|
>>>>> | | 1 | 2 | 3 | 4 | 5 | Average |
>>>>> |---------|---------|---------|---------|---------|---------|---------|
>>>>> | Data | 8.723s | 7.243s | 8.252s | 6.997s | 6.980s | 7.639s |
>>>>> | Hole | 5.271s | 5.224s | 5.060s | 4.897s | 5.321s | 5.155s |
>>>>> | Mixed | 8.050s | 10.057s | 7.919s | 8.060s | 9.557s | 8.729s |
>>>>> |---------|---------|---------|---------|---------|---------|---------|
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> NFS v4.2:
>>>>> Trial
>>>>> |---------|---------|---------|---------|---------|---------|---------|
>>>>> | | 1 | 2 | 3 | 4 | 5 | Average |
>>>>> |---------|---------|---------|---------|---------|---------|---------|
>>>>> | Data | 6.707s | 7.070s | 6.722s | 6.761s | 6.810s | 6.814s |
>>>>> | Hole | 5.152s | 5.149s | 5.213s | 5.206s | 5.312s | 5.206s |
>>>>> | Mixed | 7.979s | 7.985s | 8.177s | 7.772s | 8.280s | 8.039s |
>>>>> |---------|---------|---------|---------|---------|---------|---------|
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> #######################
>>>>> # #
>>>>> # With READ_PLUS #
>>>>> # #
>>>>> #######################
>>>>>
>>>>>
>>>>> NFS v4.1:
>>>>> Trial
>>>>> |---------|---------|---------|---------|---------|---------|---------|
>>>>> | | 1 | 2 | 3 | 4 | 5 | Average |
>>>>> |---------|---------|---------|---------|---------|---------|---------|
>>>>> | Data | 9.082s | 7.008s | 7.116s | 6.771s | 7.902s | 7.576s |
>>>>> | Hole | 5.333s | 5.358s | 5.380s | 5.161s | 5.282s | 5.303s |
>>>>> | Mixed | 8.189s | 8.308s | 9.540s | 7.937s | 8.420s | 8.479s |
>>>>> |---------|---------|---------|---------|---------|---------|---------|
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> NFS v4.2:
>>>>> Trial
>>>>> |---------|---------|---------|---------|---------|---------|---------|
>>>>> | | 1 | 2 | 3 | 4 | 5 | Average |
>>>>> |---------|---------|---------|---------|---------|---------|---------|
>>>>> | Data | 7.033s | 6.829s | 7.025s | 6.873s | 7.134s | 6.979s |
>>>>> | Hole | 1.794s | 1.800s | 1.905s | 1.811s | 1.725s | 1.807s |
>>>>> | Mixed | 7.590s | 8.777s | 9.423s | 10.366s | 8.024s | 8.836s |
>>>>> |---------|---------|---------|---------|---------|---------|---------|
>>>>>
>>>>
>>>> So there is a clear win in the 100% hole case here, but otherwise the
>>>> statistical fluctuations are dominating the numbers. Can you get us a
>>>> little more stats and then perhaps run the results through nfsometer?
>>>
>>> Also, could you describe the setup (are these still kvm's), and how
>>> you're clearing the cache between runs?
>>
>> These are still KVMs and my server is exporting an xfs filesystem. I clear
>> caches by running "echo 3 > /proc/sys/vm/drop_caches" on the server before
>> every read, and I remount my client after reading each set of three files
>> once.
>
> What sort of device is the exported xfs filesystem on? (Can't there
> be a second level of caching on the guest, depending on how it's set
> up?)
My host is a macbook pro running Archlinux, and I have all my virtio disks set
to "cache mode = none". Let me know if you were asking something different!
>
> Can we get results on bare metal? (The kvm test might be a good
> worst-case for read_plus, as I'd expect bandwidth to be relatively high
> compared to the cost of the extra memcpy's or seek calls. But it also
> seems more complicated.)
I do all of my testing on kvm these days! I'll see how difficult it is to
setup refind with a custom kernel to test between my laptop and my desktop (or
I could run the test between my raspberry pis!)
Anna
>
> --b.
>
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