Re: Should we cacheline align PGXACT?

On 1 March 2017 at 04:50, Ashutosh Sharma <ashu(dot)coek88(at)gmail(dot)com> wrote:

> On Tue, Feb 28, 2017 at 11:44 PM, Simon Riggs <simon(at)2ndquadrant(dot)com>
> wrote:
>
>> On 28 February 2017 at 11:34, Ashutosh Sharma <ashu(dot)coek88(at)gmail(dot)com>
>> wrote:
>>
>>
>>> So, Here are the pgbench results I got with '
>>> *reduce_pgxact_access_AtEOXact.v2.patch*' on a read-write workload.
>>>
>>
>> Thanks for performing a test.
>>
>> I see a low yet noticeable performance gain across the board on that
>> workload.
>>
>> That is quite surprising to see a gain on that workload. The main
>> workload we have been discussing was the full read-only test (-S). For that
>> case the effect should be much more noticeable based upon Andres' earlier
>> comments.
>>
>> Would it be possible to re-run the test using only the -S workload?
>> Thanks very much.
>>
>
> Okay, I already had the results for read-oly workload but just forgot to
> share it along with the results for read-write test. Here are the results
> for read-only
> test,
>

Thanks for conducting those comparisons.

So we have variable and sometimes significant gains, with no regressions.

By the shape of the results this helps in different places to the alignment
patch. Do we have evidence to commit both?

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