Skip site navigation (1) Skip section navigation (2)

Re: [BUGS] BUG #2401: spinlocks not available on amd64

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Theo Schlossnagle <jesus(at)omniti(dot)com>
Cc: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>, josh(dot)berkus(at)sun(dot)com, robert(dot)lor(at)sun(dot)com, PostgreSQL-patches <pgsql-patches(at)postgresql(dot)org>
Subject: Re: [BUGS] BUG #2401: spinlocks not available on amd64
Date: 2006-04-29 19:34:28
Message-ID: 26185.1146339268@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-bugspgsql-patches
Theo Schlossnagle <jesus(at)omniti(dot)com> writes:
> I'd remind everyone that the spinlock stuff is entirely optional at 
> build time.

Not really.  The performance hit for not having hardware spinlocks is
so severe that it's not considered a reasonable fallback.

> I also think it immensely useful to replace all of the tas subsystem 
> with cas so that one could reliabily lock these atomics with the process 
> id of the locker.

I cannot, ever once in my years working on Postgres, remember having
wanted such a thing.  I am strongly against mucking with the spinlock
code for mere aesthetics --- it's too fragile and hard to test,
especially on platforms you don't have ready access to.

In short, it ain't broken and we don't need to fix it.

			regards, tom lane

In response to

Responses

pgsql-bugs by date

Next:From: Bruce MomjianDate: 2006-04-30 00:16:16
Subject: Re: [BUGS] BUG #2401: spinlocks not available on amd64
Previous:From: Stephan SzaboDate: 2006-04-29 15:42:48
Subject: Re: BUG #2412: Foreing key accept nulls

pgsql-patches by date

Next:From: Tom LaneDate: 2006-04-29 21:04:35
Subject: Re: Patch for BUG #2073: Can't drop sequence when created
Previous:From: Martijn van OosterhoutDate: 2006-04-29 19:27:03
Subject: Re: Cleaning up multiply-defined-symbol warnings on OS X

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group