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<body>Excellent article on the complexity's of swap!<br><br>At some point I'm just gonna have to bite the bullet, run a large job with no real value and see what breaks with some different methods.<br><br><div class="gmail_quote">On February 8, 2021 3:26:40 PM EST, Calvin Harrigan via Ale <ale@ale.org> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div class="moz-cite-prefix">On 2/8/2021 15:09, Solomon Peachy via
Ale wrote:<br>
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<blockquote type="cite" cite="mid:20210208200929.GA3284347@shaftnet.org">
<pre class="moz-quote-pre" wrap="">On Mon, Feb 08, 2021 at 02:13:55PM -0500, Jim Kinney via Ale wrote:
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<pre class="moz-quote-pre" wrap="">Will the kernel move Bob's process from ram to swap and back if it
sits in STOP for a while (hours to days)? Unknown how long after Mary
starts that it eats all the RAM.
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<pre class="moz-quote-pre" wrap="">
It won't automatically move Bob's process to swap in one fell swoop;
instead as Mary's process needs more RAM, Bob's will get incrementally
paged out as it's not actively being accessed.
And when Mary's is finished, once Bob's is allowed to resume, it will
get incremetnally paged back in as its components are needed. (There's
probably a tunable or other mechanism to "encourage" it to page back in
more quickly, beyond running swapoff and forcing everything back..)
Performance is going to suffer while the paging is happening.
Perhaps a better option is the explicit checkpoint/restore mechanism using
the criu tool.
- Solomon
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<p>Not 100% sure if it applies to this situation, but you might want
to look into the "swappiness" setting.</p>
<p><a class="moz-txt-link-freetext" href="https://www.howtogeek.com/449691/what-is-swapiness-on-linux-and-how-to-change-it/">https://www.howtogeek.com/449691/what-is-swapiness-on-linux-and-how-to-change-it/</a><br>
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</blockquote></div><br>-- <br>Computers amplify human error<br>Super computers are really cool</body></html>