Re: Speed up Clog Access by increasing CLOG buffers

On Wed, Sep 7, 2016 at 1:08 AM, Tomas Vondra
<tomas(dot)vondra(at)2ndquadrant(dot)com> wrote:
> On 09/06/2016 04:49 AM, Amit Kapila wrote:
>> On Mon, Sep 5, 2016 at 11:34 PM, Tomas Vondra
>> <tomas(dot)vondra(at)2ndquadrant(dot)com> wrote:
>>>
>>>
>>> On 09/05/2016 06:03 AM, Amit Kapila wrote:
>>>> So, in short we have to compare three
>>>> approaches here.
>>>>
>>>> 1) Group mode to reduce CLOGControlLock contention
>>>> 2) Use granular locking model
>>>> 3) Use atomic operations
>>>>
>>>> For approach-1, you can use patch [1]. For approach-2, you can use
>>>> 0001-Improve-64bit-atomics-support patch[2] and the patch attached
>>>> with this mail. For approach-3, you can use
>>>> 0001-Improve-64bit-atomics-support patch[2] and the patch attached
>>>> with this mail by commenting USE_CONTENT_LOCK. If the third doesn't
>>>> work for you then for now we can compare approach-1 and approach-2.
>>>>
>>>
>>> OK, I can compile all three cases - but onl with gcc 4.7 or newer. Sadly
>>> the 4-socket 64-core machine runs Debian Jessie with just gcc 4.6 and my
>>> attempts to update to a newer version were unsuccessful so far.
>>>
>>
>> So which all patches your are able to compile on 4-socket m/c? I
>> think it is better to measure the performance on bigger machine.
>
> Oh, sorry - I forgot to mention that only the last test (with
> USE_CONTENT_LOCK commented out) fails to compile, because the functions
> for atomics were added in gcc-4.7.
>

No issues, in that case we can leave the last test for now and do it later.

--
With Regards,
Amit Kapila.
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