Re: [HACKERS] Re: hackers-digest V1 #771 (safe/fast I/O) - Mailing list pgsql-hackers

From ocie@paracel.com
Subject Re: [HACKERS] Re: hackers-digest V1 #771 (safe/fast I/O)
Date
Msg-id 9804222132.AA29047@dolomite.paracel.com
Whole thread Raw
In response to Re: [HACKERS] Re: hackers-digest V1 #771 (safe/fast I/O)  (Hal Snyder <hal@vailsys.com>)
List pgsql-hackers
Hal Snyder wrote:
>
> Here's a belated footnote to Paul Vixie's helpful posting of April 12:
>
> > Date: Sun, 12 Apr 1998 16:38:02 -0700
> > From: Paul A Vixie <paul@vix.com>
> > Sender: owner-pgsql-hackers@hub.org
> > Precedence: bulk
> >
> > mmap() is cool since it avoids copying data between kernel and user address
> > spaces.  However, mmap() is going to be either synchronous ("won't return 'til
> > it has set up the page table stuff and maybe allocated backing store") or not
> > ("will return immediately but your process will silently block if you try to
> > access the address range before the back office work is done for the region").
> > There is no callback facility and no way to poll for region readiness.
> ...
>
> In the case of FreeBSD, there is no callback facility, this is true,
> but you can poll for region readiness via mincore().

I don't believe mincore is universally implemented either.

Ocie

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