[ale] Ram, sigstop, swap, pids, etc

[Jim Kinney]

Excellent article on the complexity's of swap!

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.

On February 8, 2021 3:26:40 PM EST, Calvin Harrigan via Ale <ale at ale.org> wrote:
>On 2/8/2021 15:09, Solomon Peachy via Ale wrote:
>> On Mon, Feb 08, 2021 at 02:13:55PM -0500, Jim Kinney via Ale wrote:
>>> 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.
>> 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
>>
>> _______________________________________________
>> Ale mailing list
>> Ale at ale.org
>> https://mail.ale.org/mailman/listinfo/ale
>> See JOBS, ANNOUNCE and SCHOOLS lists at
>> http://mail.ale.org/mailman/listinfo
>
>Not 100% sure if it applies to this situation, but you might want to 
>look into the "swappiness" setting.
>
>https://www.howtogeek.com/449691/what-is-swapiness-on-linux-and-how-to-change-it/

-- 
Computers amplify human error
Super computers are really cool
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mail.ale.org/pipermail/ale/attachments/20210208/f7d9bce3/attachment.html>