Re: [HACKERS] Reorganization of spinlock defines - Mailing list pgsql-patches

From Bruce Momjian
Subject Re: [HACKERS] Reorganization of spinlock defines
Date
Msg-id 200309120333.h8C3Xn127277@candle.pha.pa.us
Whole thread Raw
In response to Re: [HACKERS] Reorganization of spinlock defines  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: [HACKERS] Reorganization of spinlock defines  (Tom Lane <tgl@sss.pgh.pa.us>)
Re: [HACKERS] Reorganization of spinlock defines  ("Marc G. Fournier" <scrappy@postgresql.org>)
List pgsql-patches
Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > Yes, we could do just the configure warning, then plaster tests into the
> > port files to try to hit all the opteron/itanium cases.  I am a little
> > concerned that this might throw up a bunch of problem cases that we will
> > patching for a while.
>
> Probably so --- but we'd only be breaking new platforms that people are
> starting to use, not old ones that might not be getting tested
> regularly.

Looking at the code, I wonder if we already have folks not using
spinlocks, and not even knowing it.  I don't think problem reports will
be limited to new platforms.

> Understand that I'm not dead set against applying this patch for 7.4.
> (On a code-cleanliness point of view I favor it.)  What I want is some
> open discussion about the risks and benefits before we decide.

Sure, and I am not pushing the patch.  I am just saying it would have
been ideal a few weeks ago --- I am not sure if we are worse off with or
without it.

I just learned from Larry that Unixware defines intel as i386, not
__i386 or __i386__, at least of the native SCO compiler that he uses.

What the code used to do is define NEED_I386_TAS_ASM unconditionally on
some platforms (negating the need to test for a compiler symbol) or test
for each platform compiler symbol (and not test all possible ways it
could be specified), like FreeBSD did.  That's why things are so messy.
I am going to test for __cpu, __cpu__, and cpu on non-gcc compiler for
consistency.  It is only done in one place in the patch, so that should
be good.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

pgsql-patches by date:

Previous
From: Tom Lane
Date:
Subject: Re: [HACKERS] Reorganization of spinlock defines
Next
From: Tom Lane
Date:
Subject: Re: [HACKERS] Reorganization of spinlock defines