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Re: processes and swapping
Sukanto Ghosh wrote:
1. How to determine the number of processes in memory ? (inside
kernel code, not shell : ps -ef | wc -l )
Add up all the processes with a non-zero RSS.
2. Is there any provision for swapping out entire process in linux (as
solaris has) ?
Doing that is just not realistic any more on modern systems.
Over the past 15 years, memory sizes have increased by a factor
1000 while disk seek times were reduced by a factor 8 and disk
throughput has increased by a factor 20 or so.
Programs have also increased with the size of memory.
That means the latency involved with swapping a whole process
has increased by about a factor 10-100 in the last 15 years.
In short, whole process swapping is way too slow on modern
systems.
If no, then how to make sure that a process all of whose pages have
been swapped out is not scheduled again ? (may be by changing the
process-state)
And, how to later enable the process so that it gets scheduled ?
You can stop and continue processes from userspace, look into
SIGSTOP and SIGCONT.
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