From: aggelos Date: Sat, 6 Mar 2010 20:17:41 +0000 (-0800) Subject: Add Proportional RSS X-Git-Url: https://gitweb.dragonflybsd.org/ikiwiki.git/commitdiff_plain/4eb671b807da526a808c2e8f5b2bd0491a57206e Add Proportional RSS --- diff --git a/docs/developer/gsoc2010/index.mdwn b/docs/developer/gsoc2010/index.mdwn index c9de84d2..4a781ff2 100644 --- a/docs/developer/gsoc2010/index.mdwn +++ b/docs/developer/gsoc2010/index.mdwn @@ -310,6 +310,28 @@ Meta information: * Difficulty: Easy (but extensive) * Contact point: kernel@crater.dragonflybsd.org +--- + +##### 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 + --- (please add)