Add Proportional RSS

diff --git a/docs/developer/gsoc2010/index.mdwn b/docs/developer/gsoc2010/index.mdwn
index c9de84d..4a781ff 100644 (file)
--- a/docs/developer/gsoc2010/index.mdwn
+++ b/docs/developer/gsoc2010/index.mdwn
@@ -312,4 +312,26 @@ Meta information:
 
 ---
 
+##### Proportional RSS
+
+The Resident Stack Size displayed by top keeps track of the number of resident pages in
+a certain process's adress space. It is very useful to locate memory hogs, but doesn't take
+into account page sharing. For example, if N processes map library L and L's resident pages
+are 1G, this 1G is added to the RSS of all N processes. A more useful number would be the
+Proportional (or Effective) RSS, for which we divide the number of mapped shared pages by
+the number of processes sharing each page. So in the previous example we would add 1GB/N
+to each process that has L mapped.
+
+The goal of this project is to hack the kernel to allow for effective calculation of the
+Proportional RSS and modify top to use it in addition to the RSS (i.e. it should display it by
+default and be able to sort based on it).
+
+Meta information:
+
+* Prerequisites: C, Elementary OS internals
+* Difficulty: Easy
+* Contact point: Aggelos Economopoulos <aoiko@cc.ece.ntua.gr>
+
+---
+
  (please add)