[prev in list] [next in list] [prev in thread] [next in thread] 

List:       postgresql-general
Subject:    Re: [HACKERS] spinlocks on HP-UX
From:       Tom Lane <tgl () sss ! pgh ! pa ! us>
Date:       2011-12-29 22:26:16
Message-ID: 29635.1325197576 () sss ! pgh ! pa ! us
[Download RAW message or body]

Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
> The Linux kernel does this (arch/powerpc/include/asm/ppc-opcode.h):

Yeah, I was looking at that too.

> We can't copy-paste code from Linux directly, and I'm not sure I like 
> that particular phrasing of the macro, but perhaps we should steal the 
> idea and only use the hint on 64-bit PowerPC processors?

The info that I've found says that the hint exists beginning in POWER6,
and there were certainly 64-bit Power machines before that.  However,
it might be that the only machines that actually spit up on the hint bit
(rather than ignore it) were 32-bit, in which case this would be a
usable heuristic.  Not sure how we can research that ... do we want to
just assume the kernel guys know what they're doing?

			regards, tom lane

-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
[prev in list] [next in list] [prev in thread] [next in thread]