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SIGSTOP on UNIX sistems
https://forum.osdev.org/viewtopic.php?f=15&t=32894		 Page 1 of 1
Author:  mondelob [ Thu Apr 26, 2018 8:37 am ]
Post subject:  SIGSTOP on UNIX sistems
When you issue a SIGSTOP on UNIX sistems (for example, when you send the CTRL+Z command to put the program on background), the memory used by the process it's still allocated, or saves the map of this memory, to allow other process use memory?
Thank you
Author:  Brendan [ Thu Apr 26, 2018 9:11 am ]
Post subject:  Re: SIGSTOP on UNIX sistems
Hi,

mondelob wrote:
When you issue a SIGSTOP on UNIX sistems (for example, when you send the CTRL+Z command to put the program on background), the memory used by the process it's still allocated, or saves the map of this memory, to allow other process use memory?


SIGSTOP only pauses execution for a little while (until you send SIGCONT to make it continue again). It doesn't make sense to free any memory (and then crash when SIGCONT is sent); but might make sense to consider the process' pages "less likely to be needed soon" for the purposes of figuring out which pages to send to swap space (rather than using pure "least recently used" as the basis of what to send to swap space).


Cheers,

Brendan
Author:  mondelob [ Fri Apr 27, 2018 1:10 am ]
Post subject:  Re: SIGSTOP on UNIX sistems
Brendan wrote:
Hi,

mondelob wrote:
When you issue a SIGSTOP on UNIX sistems (for example, when you send the CTRL+Z command to put the program on background), the memory used by the process it's still allocated, or saves the map of this memory, to allow other process use memory?


SIGSTOP only pauses execution for a little while (until you send SIGCONT to make it continue again). It doesn't make sense to free any memory (and then crash when SIGCONT is sent); but might make sense to consider the process' pages "less likely to be needed soon" for the purposes of figuring out which pages to send to swap space (rather than using pure "least recently used" as the basis of what to send to swap space).


Cheers,

Brendan


Thanks!
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