On Thu, Mar 26, 2015 at 11:47 AM, Anna Schumaker
<Anna.Schumaker@xxxxxxxxxx> 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.
I agree that you have to use the 'drop_caches' interface on the
server, but why not just use O_DIRECT on the clients?
--
Trond Myklebust
Linux NFS client maintainer, PrimaryData
trond.myklebust@xxxxxxxxxxxxxxx
|