From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | Alvaro Herrera <alvherre(at)2ndquadrant(dot)com> |
Cc: | pgsql-hackers(at)postgresql(dot)org, "Aaron W(dot) Swenson" <titanofold(at)gentoo(dot)org> |
Subject: | Re: 9.4 broken on alpha |
Date: | 2015-08-25 21:02:22 |
Message-ID: | 19758.1440536542@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Alvaro Herrera <alvherre(at)2ndquadrant(dot)com> writes:
> Aaron W. Swenson wrote:
>> In the 4 years that that particular line has been there, not once had
>> anyone else run into it on Gentoo until a couple months ago.
>> And it isn't a case of end users missing it as we have arch testers
>> that test packages before marking them suitable for public consumption.
>> Alpha is one of the arches.
> This means that not once has anybody compiled in an Alpha in 4 years.
Well, strictly speaking, there were no uses of pg_read_barrier until 9.4.
However, pg_write_barrier (which used "wmb") was in use since 9.2; so
unless you're claiming your assembler knows wmb but not rmb, the code's
failed to compile for Alpha since 9.2.
>> As for the dropped support, has the Alpha specific code been ripped
>> out? Would it still presumably run on Alpha?
> Yes, code has been ripped out. I would assume that it doesn't build at
> all anymore, but maybe what happens is you get spinlocks emulated with
> semaphores and it's only horribly slow.
The whole business about laxer-than-average memory coherency gives me the
willies, though. It's fairly likely that PG has never worked right on
multi-CPU Alphas.
regards, tom lane
From | Date | Subject | |
---|---|---|---|
Next Message | Joe Conway | 2015-08-25 21:27:56 | Re: One question about security label command |
Previous Message | Alvaro Herrera | 2015-08-25 21:01:26 | Re: Make HeapTupleSatisfiesMVCC more concurrent |