<br><br><div class="gmail_quote">On Thu, Feb 21, 2013 at 10:45 AM, Mandeep Sandhu <span dir="ltr"><<a href="mailto:mandeepsandhu.chd@gmail.com" target="_blank">mandeepsandhu.chd@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="im">> I know the pages are kept on disk initially and then swapped in as needed/referenced. Thus if there are code pages where none of the code in the page has been executed since starting the app, then that page will remain on disk until the application logic eventually invokes it. At that point it will be demand loaded from disk.<br>
><br>
> During that early stage, do the never used pages show as swapped out? If so, why would anyone want all those never used pages to be brought into ram just to sit there unused?<br>
<br>
</div>Are you saying that pages of code segment (of an executable) which<br>
have not been accessed yet, are copied onto the swap space from their<br>
location on the disk when the program is exec'ed? Or do they remain on<br>
disk (in their original location) and loaded into memory only when<br>
accessed (and _then_ possibly swapped out)? If they remain on disk,<br>
then that wouldn't show up in swap space, right?<br></blockquote><div><br>If the code segment of an executable which hasn't been accessed, they will remain on disk because they have fixed filesystem backing. Only when they are referenced, they will go to cache and then when inactive and/or while reclaiming, they will end up in disk again. But, afaik, anything which has a filesystem backing, a fixed storage backing, doesn't go to swap. This part is pretty clear to me. Only anon pages go to swap and something which is on disk, is not anon in first place. <br>
<br>Soham<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
-mandeep<br>
<div class="im"><br>
><br>
> The end result is that that swap'ed pages represent pages available to be swapped in, but not the number of pages that were actually swapped out at some point in time.<br>
><br>
> Greg<br>
> --<br>
> Sent from my Android phone with K-9 Mail. Please excuse my brevity.<br>
><br>
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