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

Re: Solaris ISM Testing

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
Cc: "P(dot)J(dot) \"Josh\" Rovero" <rovero(at)sonalysts(dot)com>,PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Solaris ISM Testing
Date: 2002-02-22 05:47:10
Message-ID: 14588.1014356830@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-hackers
Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> The attached email shows that Solaris benefits from the ISM or Intimate
> Shared Memory setting during shmat() shared memory creation.  It causes
> processes mapping the same shared memory to shared mapping pages _and_
> locks the pages in RAM.

Huh?  I understand "locks the pages in RAM" but I don't understand the
first part of that.  ISTM shared memory is shared memory; if we didn't
share it without this flag, we'd not be working at all on Solaris.

> I know many OS's lock shared memory in RAM anyway, or have OS parameters
> that control this (FreeBSD), but it seems Solaris does this on a per
> shmat() basis.  Should we add this flag to shmat() calls for Solaris?

Certainly on any OS where we can request pinning our shmem in RAM, we
should do so --- I've pointed out before that allowing our disk buffers
to be swapped out can't be anything but counterproductive.  Not sure
that this should be thought of as an "#ifdef SOLARIS" kind of change;
do any other Unixen share this aspect of the API?

			regards, tom lane

In response to

Responses

pgsql-hackers by date

Next:From: Bruce MomjianDate: 2002-02-22 05:52:59
Subject: Re: Solaris ISM Testing
Previous:From: Bruce MomjianDate: 2002-02-22 05:46:59
Subject: Re: Pls, apply patch....

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