Re: Terminal command to disable disk swapping in El Capitan

Subject	Re: Terminal command to disable disk swapping in El Capitan
Newsgroups	comp.sys.mac.system
References	(4 earlier) <310720151724400777%nospam@nospam.invalid> <ncidnWpz39vsQiHInZ2dnUU7-QmdnZ2d@giganews.com> <55bcef11$0$59315$b1db1813$2411a48f@news.astraweb.com> <0rKdnah3579TySDInZ2dnUU7-eednZ2d@giganews.com> <55bd7b1d$0$16701$c3e8da3$76a7c58f@news.astraweb.com>
From	Alan Browne <alan.browne@freelunchvideotron.ca>
Date	2015-08-02 09:36 -0400
Message-ID	<_ZudnVd30Kl-gSPInZ2dnUU7-dOdnZ2d@giganews.com> (permalink)

Show all headers | View raw

On 2015-08-01 22:06, JF Mezei wrote:
> On 15-08-01 19:22, Alan Browne wrote:
>
>>           sudo launchctl unload -w
>> /System/Library/LaunchDaemons/com.apple.dynamic_pager.plist
>
> This would not disable virtual memory. Virtual memory is setup very
> early in the boot, well before launchd starts processes left and right.

It renders VM into a mapper w/o recourse to disk space at all - as I 
replied previously.

>
>> SIP, as I understand it, protects certain file locations, not memory.
>
> executables read from files that are SIP protected also have write
> protect in the memory pages. If you don't want hackers to change a
> sensitive piece of  code, it makes sense to protect both the on-disk
> file, and the memory pages once that file has been loaded onto memory.

I haven't seen that described anywhere - everything I've seen refers to 
system file folders being protected.  Protected memory is another 
feature of the OS that's already in place.
>
>> A good point in light of terms.  What is meant is "swapping".  However,
>> once one removes paging then I don't think VM will work as a proper VM.
>
> yes it does. YOu need to think about shareable images/libraries. One
> copy exists in physical memory, and different processes map those
> physical pages into their own address space.
>
> Similarly, when you map a file to memory, (instead of reading all its
> contents), it acts as a read-ony page file where the virtual memory
> system will map that file to your process' address space and when you
> program wants to access a certain memory location, it automatically
> causes the pager to fetch the data from the disk and loads it into that
> memory location. (so if you map a huge file to memory, only the contents
> you access are actually loaded and the VM system will discard memory
> pages that are no longer needed, knowing it can re-read them from file
> if necessary)

If the pager is turned off (per the command above), then I doubt that 
will work.  So VM will have to map to existing memory.

> There is a lot more to virtual memory than just shoving physical memory
> to disk when physical memory is short.

I don't disagree with that part of it.  I'm really more concerned with 
avoiding page swapping to disk that is absolutely not required on a 
machine with a large physical memory.  Paging can be turned off as 
above, swaps stop, computer faster (justifying the expense of the memory).

Back to comp.sys.mac.system | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

Terminal command to disable disk swapping in El Capitan John Albert <j.albert@snet.net> - 2015-07-31 11:26 -0400
  Re: Terminal command to disable disk swapping in El Capitan nospam <nospam@nospam.invalid> - 2015-07-31 11:47 -0400
    Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-07-31 12:01 -0400
      Re: Terminal command to disable disk swapping in El Capitan nospam <nospam@nospam.invalid> - 2015-07-31 12:07 -0400
        Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-07-31 12:36 -0400
          Re: Terminal command to disable disk swapping in El Capitan nospam <nospam@nospam.invalid> - 2015-07-31 12:46 -0400
            Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-07-31 13:45 -0400
              Re: Terminal command to disable disk swapping in El Capitan nospam <nospam@nospam.invalid> - 2015-07-31 14:06 -0400
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-01 10:35 -0400
          Re: Terminal command to disable disk swapping in El Capitan Jolly Roger <jollyroger@pobox.com> - 2015-07-31 20:52 +0000
            Re: Terminal command to disable disk swapping in El Capitan billy@MIX.COM - 2015-08-01 09:13 +0000
              Re: Terminal command to disable disk swapping in El Capitan Jolly Roger <jollyroger@pobox.com> - 2015-08-01 14:03 +0000
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-01 10:13 -0400
                Re: Terminal command to disable disk swapping in El Capitan Jolly Roger <jollyroger@pobox.com> - 2015-08-01 14:51 +0000
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-01 11:12 -0400
                Re: Terminal command to disable disk swapping in El Capitan Jolly Roger <jollyroger@pobox.com> - 2015-08-01 18:39 +0000
                Re: Terminal command to disable disk swapping in El Capitan dempson@actrix.gen.nz (David Empson) - 2015-08-02 10:45 +1200
                Re: Terminal command to disable disk swapping in El Capitan Jolly Roger <jollyroger@pobox.com> - 2015-08-02 06:31 +0000
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-01 19:23 -0400
                Re: Terminal command to disable disk swapping in El Capitan billy@MIX.COM - 2015-08-02 16:07 +0000
                Re: Terminal command to disable disk swapping in El Capitan Jolly Roger <jollyroger@pobox.com> - 2015-08-02 16:13 +0000
                Re: Terminal command to disable disk swapping in El Capitan nmassello@yahoo.com (Neill Massello) - 2015-08-02 20:40 -0600
                Re: Terminal command to disable disk swapping in El Capitan billy@MIX.COM - 2015-08-02 16:55 +0000
                Re: Terminal command to disable disk swapping in El Capitan Jolly Roger <jollyroger@pobox.com> - 2015-08-02 17:20 +0000
                Re: Terminal command to disable disk swapping in El Capitan JF Mezei <jfmezei.spamnot@vaxination.ca> - 2015-08-02 13:35 -0400
                Re: Terminal command to disable disk swapping in El Capitan Jolly Roger <jollyroger@pobox.com> - 2015-08-02 17:51 +0000
              Re: Terminal command to disable disk swapping in El Capitan nospam <nospam@nospam.invalid> - 2015-08-01 11:54 -0400
            Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-01 10:24 -0400
          Re: Terminal command to disable disk swapping in El Capitan nmassello@yahoo.com (Neill Massello) - 2015-08-02 08:28 -0600
            Re: Terminal command to disable disk swapping in El Capitan nospam <nospam@nospam.invalid> - 2015-08-02 10:40 -0400
              Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-02 10:48 -0400
                Re: Terminal command to disable disk swapping in El Capitan nospam <nospam@nospam.invalid> - 2015-08-02 10:56 -0400
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-02 11:00 -0400
                Re: Terminal command to disable disk swapping in El Capitan nospam <nospam@nospam.invalid> - 2015-08-02 11:02 -0400
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-02 11:31 -0400
                Re: Terminal command to disable disk swapping in El Capitan nospam <nospam@nospam.invalid> - 2015-08-02 11:40 -0400
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-02 12:00 -0400
                Re: Terminal command to disable disk swapping in El Capitan billy@MIX.COM - 2015-08-02 16:26 +0000
                Re: Terminal command to disable disk swapping in El Capitan Jolly Roger <jollyroger@pobox.com> - 2015-08-02 16:31 +0000
                Re: Terminal command to disable disk swapping in El Capitan billy@MIX.COM - 2015-08-02 17:13 +0000
                Re: Terminal command to disable disk swapping in El Capitan Jolly Roger <jollyroger@pobox.com> - 2015-08-02 17:27 +0000
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-02 20:47 -0400
            Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-02 10:40 -0400
              Re: Terminal command to disable disk swapping in El Capitan nospam <nospam@nospam.invalid> - 2015-08-02 10:47 -0400
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-02 10:53 -0400
                Re: Terminal command to disable disk swapping in El Capitan nospam <nospam@nospam.invalid> - 2015-08-02 10:56 -0400
              Re: Terminal command to disable disk swapping in El Capitan nmassello@yahoo.com (Neill Massello) - 2015-08-02 11:48 -0600
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-02 21:08 -0400
                Re: Terminal command to disable disk swapping in El Capitan Jolly Roger <jollyroger@pobox.com> - 2015-08-03 01:25 +0000
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-03 08:10 -0400
                Re: Terminal command to disable disk swapping in El Capitan Jolly Roger <jollyroger@pobox.com> - 2015-08-03 13:32 +0000
      Re: Terminal command to disable disk swapping in El Capitan John Albert <j.albert@snet.net> - 2015-07-31 17:04 -0400
        Re: Terminal command to disable disk swapping in El Capitan nospam <nospam@nospam.invalid> - 2015-07-31 17:24 -0400
          Re: Terminal command to disable disk swapping in El Capitan Don Bruder <dakidd@sonic.net> - 2015-07-31 15:30 -0700
            Re: Terminal command to disable disk swapping in El Capitan nospam <nospam@nospam.invalid> - 2015-07-31 18:36 -0400
              Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-01 11:08 -0400
                Re: Terminal command to disable disk swapping in El Capitan Tim Streater <timstreater@greenbee.net> - 2015-08-01 16:45 +0100
                Re: Terminal command to disable disk swapping in El Capitan nospam <nospam@nospam.invalid> - 2015-08-01 11:54 -0400
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-01 18:57 -0400
                Re: Terminal command to disable disk swapping in El Capitan nmassello@yahoo.com (Neill Massello) - 2015-08-02 07:45 -0600
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-02 10:09 -0400
                Re: Terminal command to disable disk swapping in El Capitan nmassello@yahoo.com (Neill Massello) - 2015-08-02 11:48 -0600
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-02 21:04 -0400
          Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-01 11:02 -0400
            Re: Terminal command to disable disk swapping in El Capitan JF Mezei <jfmezei.spamnot@vaxination.ca> - 2015-08-01 12:08 -0400
              Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-01 19:22 -0400
                Re: Terminal command to disable disk swapping in El Capitan JF Mezei <jfmezei.spamnot@vaxination.ca> - 2015-08-01 22:06 -0400
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-02 09:36 -0400
                Re: Terminal command to disable disk swapping in El Capitan JF Mezei <jfmezei.spamnot@vaxination.ca> - 2015-08-02 11:39 -0400
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-02 11:58 -0400
                Re: Terminal command to disable disk swapping in El Capitan JF Mezei <jfmezei.spamnot@vaxination.ca> - 2015-08-02 13:42 -0400
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-02 20:53 -0400
                Re: Terminal command to disable disk swapping in El Capitan JF Mezei <jfmezei.spamnot@vaxination.ca> - 2015-08-02 21:31 -0400
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-03 08:12 -0400
                Re: Terminal command to disable disk swapping in El Capitan JF Mezei <jfmezei.spamnot@vaxination.ca> - 2015-08-03 15:42 -0400
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-05 09:06 -0400
                Re: Terminal command to disable disk swapping in El Capitan Alan Baker <email@domain.com> - 2015-08-02 21:22 -0700
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-03 08:16 -0400
                Re: Terminal command to disable disk swapping in El Capitan Alan Baker <email@domain.com> - 2015-08-03 20:56 -0700
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-05 09:11 -0400
                Re: Terminal command to disable disk swapping in El Capitan JF Mezei <jfmezei.spamnot@vaxination.ca> - 2015-08-05 12:40 -0400
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-05 18:53 -0400
                Re: Terminal command to disable disk swapping in El Capitan JF Mezei <jfmezei.spamnot@vaxination.ca> - 2015-08-06 00:02 -0400
                Re: Terminal command to disable disk swapping in El Capitan Tim Streater <timstreater@greenbee.net> - 2015-08-06 16:25 +0100
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-06 11:25 -0400
                Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-06 11:33 -0400
              Re: Terminal command to disable disk swapping in El Capitan John Albert <j.albert@snet.net> - 2015-08-04 23:01 -0400
        Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-08-01 10:47 -0400
          Re: Terminal command to disable disk swapping in El Capitan billy@MIX.COM - 2015-08-02 16:02 +0000
            Re: Terminal command to disable disk swapping in El Capitan Warren Oates <warren.oates@gmail.com> - 2015-08-02 13:39 -0400
  Re: Terminal command to disable disk swapping in El Capitan Alan Browne <alan.browne@freelunchvideotron.ca> - 2015-07-31 12:01 -0400

csiph-web