memory slop

Brandon Moore brandon_m_moore at
Tue Mar 22 17:47:21 CET 2011

> On Tue, March 22, 2011 21:00:29 Tim Docker <twd2 at> wrote:

> I'm a bit shocked at the amount of wasted memory here. The sample  data file 
>has ~61k key/value pair. Hence ~122k ByteStrings - as you point  out
> many of these are very small (1500 of them are empty). Assuming it's the  
>bytestring that are generating slop, I am seeing ~500 bytes on average per  

It sounds like the space is allocated but unused pages. Unless you have messed 
with some kernel memory manager settings, unused virtual pages consume no 
physical RAM.
You could confirm this by using ps to check how much RSS is actually used, 
compared to VSZ allocated (VSZ - RSS shouldn't include any actual data unless 
your system is actively swapping stuff to disk). If it is just unsued pages it's 
not a problem.



More information about the Glasgow-haskell-users mailing list