error: ‘struct task_struct’ has no member named ‘it_virt_value’ - linux

Question

I am trying to create a system call in Linux ubuntu-studio that has the following functionality:
bring virtual memory the larger process and how much bytes it occupies.
below is the implementation code of the system call:
#include <linux/module.h>
#include <linux/printk.h>
#include <linux/sched.h>
struct pid_size{
int pid;
unsigned long size;
};
struct pid_size pid maiorMemoriaVirtual(void)
{
struct task_struct *task;
struct task_struct *maior = NULL;
for_each_process(task)
{
if(maior == NULL)
maior = task;
else if(task->it_virt_value > maior->it_virt_value)
maior = task;
}
struct pid_size retorno;
retorno.pid = maior->pid;
retorno.size = maior->it_virt_value;
return retorno;
}
When compiling to try compiling the kernel got the following error:
kernel/maiorMemoriaVirtual.c: In function ‘sys_maiorMemoriaVirtual’:
kernel/maiorMemoriaVirtual.c:19:21: error: ‘struct task_struct’ has no member named ‘it_virt_value’
else if(task->it_virt_value > maior->it_virt_value)
^
kernel/maiorMemoriaVirtual.c:19:44: error: ‘struct task_struct’ has no member named ‘it_virt_value’
else if(task->it_virt_value > maior->it_virt_value)
^
kernel/maiorMemoriaVirtual.c:23:5: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
struct pid_size retorno;
^
kernel/maiorMemoriaVirtual.c:25:25: error: ‘struct task_struct’ has no member named ‘it_virt_value’
retorno.size = maior->it_virt_value;
^
make[1]: ** [kernel/maiorMemoriaVirtual.o] Erro 1

Answer 1

I came across a similar problem while working on an assignment and I have realized that there are quite a few changes that have been made to the definition of the 'task_struct' structure.
My guess is that you are looking for accumulated virtual memory usage. You might find this link useful. Accumulated Virtual Memory usage
Link to the task_struct definition in kernel 2.6.36