Tell me more ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.
up vote 2 down vote favorite

Can the %MEM value for a process show more than 100% in top output?Is this ever possible?

share|improve this question

closed as off topic by mailq, EEAA, MikeyB, MDMarra, sysadmin1138♦ Jan 11 '12 at 0:40

Questions on Server Fault are expected to relate to professional server, networking, or related infrastructure administration within the scope defined in the FAQ. Consider editing the question or leaving comments for improvement if you believe the question can be reworded to fit within the scope. Read more about closed questions here.

1 Answer

up vote 3 down vote

No it can't. According to the manual it is only the physical memory and in real life you can not have more than 100% memory, can you?

   n: %MEM  --  Memory usage (RES)
      A task's currently used share of available physical memory.

   o: VIRT  --  Virtual Image (kb)
      The  total  amount  of  virtual  memory  used  by the task.  It
      includes all code, data and shared libraries  plus  pages  that
      have  been  swapped out and pages that have been mapped but not
      used.

   p: SWAP  --  Swapped size (kb)
      Memory that is not resident but is present in a task.  This  is
      memory  that  has been swapped out but could include additional
      non-resident memory.  This column is calculated by  subtracting
      physical memory from virtual memory.

   q: RES  --  Resident size (kb)
      The non-swapped physical memory a task has used.
share|improve this answer
What if it is using some swap? Theoretically can it ever be more than 100%? – user973430 Sep 30 '11 at 19:54
1  
Swap is virtual memory. Not physical. So you know the answer... – mailq Sep 30 '11 at 20:06
mailq is correct... another way to think of the same answer: the only way it would show >100% is if the measurement was something ridiculous... like "what is the percentage of physical memory that is taken up by physical memory and virtual memory/swap..." like "what is the percentage of bananas that is taken up by bananas and pineapples"... well 100% of the bananas + the pineapples... who cares about pineapples?! – mbrownnyc Sep 30 '11 at 20:27

Not the answer you're looking for? Browse other questions tagged or ask your own question.