This forum is in read-only mode for archive purposes, please use our new forum at https://community.justflight.com
Forum Home Forum Home > Just Chat > Just Chat - General Discussion
  New Posts New Posts RSS Feed - Windows 7
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Windows 7

 Post Reply Post Reply Page  <1 456
Author
Message
Magic Man View Drop Down
Chief Pilot
Chief Pilot
Avatar

Joined: 02 Apr 2008
Location: South Wales
Points: 5336
Post Options Post Options   Thanks (0) Thanks(0)   Quote Magic Man Quote  Post ReplyReply Direct Link To This Post Posted: 11 Jun 2009 at 9:25pm
Originally posted by VulcanB2 VulcanB2 wrote:

Quote Either way, what is the point you are trying to make and the conclusion you are coming to from the fact that "chaos" does no ensue on deletion of the physical file?

The point I am making, and you don't understand, is that the system does not care if the file is on disk or not. It has no bearing on memory and whether the system will try to page it out or not.

Clearly you're never going to understand this.

You are talking rubbish again I'm afraid. There is nothing really to understand about rubbish that I am not getting.

Again, stop skirting around the edge, your whole point was that it is somehow better to run without a page file under real conditions (not your imaginary unlimited memory scenario) which is why you switched it off. You are just posting diversionary fluff.

Okay, let's go back to the "point [you are] making" and that I apparently don't understand. Your experiment to show and prove that "the system does not care if the file is on disk or not".

You stated...
Originally posted by VulcanB2 VulcanB2 wrote:

Try this then (if you're brave enough): start MS Word (or FS if you want), then move the FS9.EXE executable someplace else. Tell me if Windows ever moans it disappeared whilst the app is running.
...
Did you not get the point when I *DELETED* the FS9.EXE file with FS running? FS9.EXE was no longer "backed by a file on the HD" as you put it. Based on what you're saying, the system should have failed because when it killed FS9.EXE in memory to load other stuff (based on your description of how it works), oops - FS9.EXE wasn't on the HD to look at.
...
As I demonstrated when I deleted the FS9.exe file - the file was no longer on disk for this behavior to work. If this is how it did work, deleting the FS9.exe file should have created chaos


Except, in reality, you never did delete the FS9.exe when it was running did you?

You just assumed that moving it or renaming it would prove the same point. Because (as I wondered earlier and later found out and verified myself) there is no worry about what happens with the pager trying to access this file that no longer exists because you are prevented from deleting the file in the first place.

Try it this time rather than assuming - you'll get a big fat dialog... "Cannot delete FS9: Access denied"

Reason why there are no issues when you move it or rename it is because the OS keeps tracks of the file so remains able to page out memory relating to it and page it back in from the file if required. FS9.exe was still "backed by a file on the HD" as I put it all along...

Now, let's move on to your issue with the fact that memory pages that are backed, i.e. those that have come directly from the hd in the form of an .exe (your fs9.exe for example) or .dlls etc are freed if required and then paged back in directly from the file. I have explained this several times.

In response to those explanations you have stated...
Originally posted by VulcanB2 VulcanB2 wrote:

See, you made the same mistake again. IT DOES NOT DO THIS.
...
Where do you get this rubbish from???????? WHAT IS YOUR TECHNICAL SOURCE FOR THIS BAD INFORMATION????
...
You will note that NOWHERE in these notes does it say it drops data that *already* resides on the hard disk in the traditional sense of a program or user data
...
No it isn't. Not at all.
...
As should be clearly apparent to you by now, no reference is ever kept of which file data came from. The system doesn't know, and it doesn't care.
...
Huh? Read my links again. Keep reading until you understand.
...
I can only summize that the reason MM is avoiding answering my question and has failed to produce any technical articles countering my position, either in whole or in part, means I am indeed correct in my assertions.


Originally posted by VulcanB2 VulcanB2 wrote:

provide links to technical descriptions that substantiate your definitions from Microsoft please.


Okay, here we go then, how about...
Quote For example, each application has an executable file that represents pages of executable code and resources for the application. These pages are swapped into and out of RAM, as they are needed, by the operating system. When a page of memory is no longer needed, the operating system relinquishes control over the page on behalf of the application that owns it and frees it for use by another. When that page becomes needed again, it is re-read from the executable file on disk. This is called backing the memory with a file, in this case, the executable file.
(emphasis mine)

and...
Quote when a process starts, pages of memory are used to store static and dynamic data for that application. Once committed, these pages are backed by the system pagefile, similar to the way the executable file is used to back the pages of code.


and...
Quote Memory used to represent pages of code in processes for Windows NT are backed directly by the application's executable module while memory used for pages of data are backed by the system pagefile.


and...
Quote Both code and data are treated the same way in Windows NT—both are represented by pages of memory and both have their pages backed by a file on disk. The only real difference is the file by which they are backed—code by the executable image and data by the system pagefile.


From where? Microsoft Developer Network. http://msdn.microsoft.com/en-us/library/ms810613.aspx - memory mapped files. You should take a look.

Also points out the benefits of using a page file for sharing data between processes which can prevent "a waste of system resources". Nice big diagrams as well showing the page file as a key part of the overall memory management - strange that if it's not really that important and not needed as you say...

Also...
Quote Yet, in Windows NT, not all pages of memory are backed by these pagefiles. Instead, Windows NT backs pages of memory that represent either code or memory-mapped files with the actual file they represent. This provides a substantial savings of disk memory by eliminating redundant information on the disk.


Same library, section detailing the virtual memory manager in Windows NT.

Originally posted by VulcanB2 VulcanB2 wrote:

I don't see performance being cited as a reson to keep it.

Strange, nothing there about the performance benefits of disabling the page file though...

Just to close with a few of your own statements...
Originally posted by VulcanB2 VulcanB2 wrote:

I see a lot of arguments without any facts to back them up.

Originally posted by VulcanB2 VulcanB2 wrote:

I still don't see any references to anything countering my position yet.

Originally posted by VulcanB2 VulcanB2 wrote:

Again, please study the link very carefully. You have a flawed understanding.

Originally posted by VulcanB2 VulcanB2 wrote:

Read my links again. Keep reading until you understand.

Originally posted by VulcanB2 VulcanB2 wrote:

I think the phrase I'm looking for here is "I've got you on the run".


I think we should call it a day there shouldn't we...

Apologies to all others for this and all the quotes here etc. Normal service will be resumed shortly...Wink
Back to Top
VulcanB2 View Drop Down
Chief Pilot
Chief Pilot
Avatar

Joined: 02 Apr 2008
Points: 13365
Post Options Post Options   Thanks (0) Thanks(0)   Quote VulcanB2 Quote  Post ReplyReply Direct Link To This Post Posted: 12 Jun 2009 at 1:03am
Quote Try it this time rather than assuming

I assumed nothing, and did try it.

This is why it can't be deleted:

http://en.wikipedia.org/wiki/Memory-mapped_file#Platform_support

Been a damn long time since I read about this.

http://msdn.microsoft.com/en-us/library/ms810613.aspx

Holy cow - I was hardly 11 years old when I last read about this (1993). FYI I've been doing this stuff since I was 4 (I started out on a System 19 - that is One Nine - writing machine code, then moved to the Motorola 6800 before I got my first PC).

I thought MMF went out back then. Didn't realize they were still using it. I never use it - thought it was depricated (back in 1995 to give you an idea - when Win 95 was released to be exact). I've only thought this for a mere 16 years. Dead  When they introduced the swap file in Win 3.x, I thought it was the replacement and MMF was simply for backwards compatibility. Those were the days!! Big%20smile

I've been bashing my head against the wall for years trying to figure out why that ****ing file won't delete when an app is running, yet you could read it. Never thought it was this method of access that was behind it (I was that convinced it was depricated).

Note carefully that the article says that all 6 memory access methods are totally independent of each other.

On this point I raise my hand and say "I'm wrong". I did quote sources though. Always important. Wink

I'm Shocked, seriously.

I still stand by my other comments though.

O/T: Still got one of these in the loft: http://en.wikipedia.org/wiki/KIM-1

...and I still use one of these! Big%20smile http://en.wikipedia.org/wiki/MEK6800D2  Damn good processor. FYI the group of 4 LEDSs are the memory address, and the group of two on the right are the data/instruction as necessary. They are split like this for easier reading whilst debugging.

0A - LOAD A
03 - DATA
0B - LOAD B
23 - DATA
1C - ACC A + ACC B -> ACC A
3F - HALT

I think that is correct. Load accumulator A with "03", load accumulator B with "23" sum the two and store in accumulator A. By looking in accumulator A I should have the value "26" (remembering it is HEX!!!!!).

Best regards,
Vulcan.
Back to Top
MartinW View Drop Down
Moderator in Command
Moderator in Command
Avatar

Joined: 31 Mar 2008
Location: United Kingdom
Points: 26722
Post Options Post Options   Thanks (0) Thanks(0)   Quote MartinW Quote  Post ReplyReply Direct Link To This Post Posted: 12 Jun 2009 at 9:39am
Game set and match to magic then? Big%20smile
 
Back to Top
Magic Man View Drop Down
Chief Pilot
Chief Pilot
Avatar

Joined: 02 Apr 2008
Location: South Wales
Points: 5336
Post Options Post Options   Thanks (0) Thanks(0)   Quote Magic Man Quote  Post ReplyReply Direct Link To This Post Posted: 12 Jun 2009 at 12:47pm
To be fair to our pointy friend, whilst looking for the backup stuff for this, it's clear that just like in any other subject misonceptions can quickly take hold and spread far and wide. There was a suprising amount of stuff  on technical sites  that got it wrong as well and they were meant to be the experts advising others.
 
Not sure if anyone else is interested but during my trawls came across the little tool available here... http://www.tmurgent.com/Tool_ATM.aspx - which gives a great view of what is going on in your PCs memory.
 
To come back to a 'issue' mentioned in the past by others (and one in particular who will remain anonymous... Wink) regarding Vista being a memory hog, using all the memory etc. to which the usual reply has become, "its designed to use all the memory it can, unused memory is wasted memory" etc. - this tool shows that very nicely. Reboot etc. and you'll see the precache stuff empty, slowly filling up as it does it's stuff, caching stuff it thinks you'll use based on past experience. If you need that memory for anything else, it'll just dump it out.
 
Originally posted by VulcanB2 VulcanB2 wrote:

I still stand by my other comments though.
Which ones? No, second thoughts, don't answer that... Big%20smile
 
(Ermm no really, don't answer that...  Hug group hug instead)
.
.
.
.
[deep voice]"Windows - the memory manager conspiracy" a Slim Martin production.[/deep voice]
 
--- The End ---
Back to Top
MartinW View Drop Down
Moderator in Command
Moderator in Command
Avatar

Joined: 31 Mar 2008
Location: United Kingdom
Points: 26722
Post Options Post Options   Thanks (0) Thanks(0)   Quote MartinW Quote  Post ReplyReply Direct Link To This Post Posted: 12 Jun 2009 at 2:21pm
Magic... run away quick, change the subject, anything, but don't dwell.
 
If you like I'll set up a diversion, 9/11 perhaps?
 
Wink
 
Edit: I've diverted him with talk of dinosaurs, lost worlds etc, in another topic.
Back to Top
VulcanB2 View Drop Down
Chief Pilot
Chief Pilot
Avatar

Joined: 02 Apr 2008
Points: 13365
Post Options Post Options   Thanks (0) Thanks(0)   Quote VulcanB2 Quote  Post ReplyReply Direct Link To This Post Posted: 12 Jun 2009 at 4:55pm
Strangely enough, I did get Process Viewer - apparently it could release all file handles without terminating the holding process.

There is one secret weapon in the arsenal I did consider:

Windows File Permissions.

Take your favorite app, and deny access to it whilst it is running.

It will prevent the process from coming back to the file later (if it ever should). Next best thing to deleting it.

Best regards,
Vulcan.
Back to Top
 Post Reply Post Reply Page  <1 456
  Share Topic   

Forum Jump Forum Permissions View Drop Down