Hello,
I came up with the following approach.
I went through the code and the book named "Implementation of free BSD
system" for some detail understanding.
There is a vmspace structure embedding vm_map structure. The vm_map
structure in turn points to the head of vm_map_entry.
The vm_map_entry points to the vm_object.
The structure vm_object contains the reference count of the number of
vm_map_entry or other objects referencing it.
Also, the vm_object structure has count of the number of resident pages.
struct vm_object {
....
int ref_count;
....
int resident_page_count;
....
};
Suppose their are 2 process, proc_A and proc_B. proc_A has three references
to a object and proc_B has 2.
Thus, now their are five references and if we divide the resident_page_count
by ref_count, we can then multiply it by 3 to get/calculate proportional RSS
for proc_A and multiplying by 2 will give it for proc_B.
Thus, we can get it without going very deep into the convoluted chain. And
which will be fast.
If you guys think its a feasible solution, I can carry it and test it. After
the testing if the results are weird we can just move forward till the depth
of the chain.
Thanks,
Pratyush Kshirsagar.
