long long size = (long long)1*1024*1024*1024;
char *p =NULL;
while (p==NULL)
{
/* mmap 100MiB of shared anonymous memory */
p = malloc(size);
if(!p)
{
printf("\nallocation failed for size %ld",size);
size = size/2;
}
else
{
printf("\nallocation passed for size %ld",size);
break;
}
}
if(p)
{
printf("\n making persinstant these allocated memory,%p",p);
/* Touch every single page to make them resident */
for (i = 0; i < size / 4096; i++)
{
printf ("\n%d",i);
p[i * 4096] = 1;
}
sleep(600) // sleep 10 min and analyze the memory used data
}
free -m [before running after code] Mon Jul 17 07:57:13 CDT 2017 total used free shared buffers cached Mem: 15950 3225 12725 1 263 1076 -/+ buffers/cache: 1885 14065 Swap: 2047 0 2047
free -m [after before running these code] total used free shared buffers cached Mem: 15950 2199 13751 1 263 1076 -/+ buffers/cache: 860 15090 Swap: 2047 0 2047
So if we see i write 1GB data ( very first time allocate successfully) and free -m shows only 1000KB being used.
Can someone help me to fill this gap. how can i verify the exact RAM uses of my code.
Thanks Vijayky88
