public inbox for gas2@sourceware.org
 help / color / mirror / Atom feed
From: "Arne H. Juul" <arnej@pvv.unit.no>
To: gas2@cygnus.com, raeburn@cygnus.com
Cc: bfd@cygnus.com
Subject: Re: mmap changes, mostly for aout right now
Date: Tue, 07 Nov 1995 17:10:00 -0000	[thread overview]
Message-ID: <9511080110.AA22833@datter.pvv.unit.no> (raw)

 > I've just checked in now some changes to bfd to use mmap for reading
 > files under certain circumstances.  A snapshot file should be available
 > within the next hour or so.  Please try it out and let me know of any
 > problems.
[...]
 > Under NetBSD (on i386), I saw no significant change in CPU time used
 > (though my test case was different -- many more small files in and out of
 > libraries).
[...]

Unless I'm very mistaken, using mmap is currently a *very* bad idea
on NetBSD.  The buffer cache and VM system hasn't been merged, and this
leads to lots of trouble when using mmap(), at least on NFS-mounted
filesystems - the file as seen by read/write can be wildly different from
the mmap view.  This will (hopefully) change later on, but currently using
mmap() on NetBSD in other than very carefully controlled circumstances
will probably lead to disaster.

  -  Arne H. J.


             reply	other threads:[~1995-11-07 17:10 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
1995-11-07 17:10 Arne H. Juul [this message]
1995-11-08 12:47 ` Ken Raeburn
  -- strict thread matches above, loose matches on Subject: below --
1995-11-06  3:20 raeburn
1995-11-07  9:39 ` Richard Stallman

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=9511080110.AA22833@datter.pvv.unit.no \
    --to=arnej@pvv.unit.no \
    --cc=bfd@cygnus.com \
    --cc=gas2@cygnus.com \
    --cc=raeburn@cygnus.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).