Hello... A hard question for me to answer....But. i'll try.. > 2. VmRSS is physical memory being used by the system. > > > Now, in case of shared libraries the space used by library will be > > added in VmRSS of all the processes which are loading it or only to > > one process. If to all process then > > > > parameter(A) + parameter(B) + parameter(C) + parameter(D) + > > parameter(E) = (MemTotal - MemFree) > > wont be satisfied. Hm, ok I admit I am a bit confused too here. OK, allow me to re phrase. What I meant by "consumed" is actually "there is a page table entry pointing to a page frame". So, in case of the dynamic shared library (like you give as illustration), the size of each shared libraries is added to RSS property of each file. This means, RSS is not really valid to describe memory consumption of a process. Hmmm, I think anon_rss describe it better, but this property doesn't include the size of file backed memory mapping. Maybe you should ask the real expert about it. Rik? Arjan? Marcelo? anyone? > > 3. free gives me the below shown output: > > > > total used free shared > > buffers > > Mem: 502180 424100 78080 0 > > 340 Swap: 0 0 0 > > Total: 502180 424100 78080 > > > > Already a lots of processes are running on my system. Is it > > buffers = 340 KB memory being used by page cache etc and remaining > > ie 512MB(524288 Kb) - 340 KB = 523948 KB should be shown as total > > (which is not matching here....???) "Total" here is not actually all the RAM that is currently installed in your motherboard. I prefer to say to name it "RAM area that is not reserved for kernel usage". if you look at /arch/i386/mm/init.c, you will notice that "Total RAM" is actually taken from totalram_pages variable. This variable represent the pages currently allocated into memory zones (ZONE_NORMAL, ZONE_DMA, ZONE_HIGHMEM) plus the memory area released after no longer need by the kernel. Where's the rest? it is reserved for kernel codes, memory holes defined in BIOS and other kernel special needs > > 4. Can you tell me any fuction in C which returns the info as shown > > in /proc/$PID/status file? > > Basically i need mem usage of that process. > > I tried getrusage() function. it return 0 for both > > usage.ru_maxrss and usage.ru_ixrss Sorry, I have no idea so far. regards, Mulyadi -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
