Robert Haas <robertmhaas@gmail.com> writes:
> On Mon, Feb 13, 2017 at 11:07 AM, Alvaro Herrera
> <alvherre@2ndquadrant.com> wrote:
>> It seems to me that Andres comments here were largely ignored:
>> https://www.postgresql.org/message-id/20160822021747.u5bqx2xwwjzac5u5@alap3.anarazel.de
>> He was suggesting to increase the struct size to 16 bytes rather than
>> going all the way up to 128. Did anybody test this?
> So, I think that going up to 128 bytes can't really make sense. If
> that's the best-performing solution here, then maybe what we ought to
> be doing is reverting the PGXACT/PGPROC separation, sticking these
> critical members at the beginning, and padding the whole PGXACT out to
> a multiple of the cache line size.
Yes. That separation was never more than a horribly ugly kluge.
I would love to see it go away. But keeping it *and* padding
PGXACT to something >= the size of PGPROC borders on insanity.
regards, tom lane