On Tue, Jan 13, 2009 at 3:42 PM, mabshoff <michael.absh...@mathematik.uni-dortmund.de> wrote: > > > > On Jan 13, 3:05 pm, Jason Grout <jason-s...@creativetrax.com> wrote: >> mabshoff wrote: > > <SNIP> > >> > This is not how this works, i.e. a lot of the memory Sage uses is >> > shared mappings between libraries, so the first notebook process is >> > much, much more expensive than subsequent ones. top and the default >> > interface it uses on Linux is dumb regarding shared mappings, i.e. >> > every notebook process is reported to use every library that is >> > dlopened by Sage. >> >> Okay, I was using top to calculate this. What is a better way to >> calculate the actual memory being used? I'd like to have an accurate >> idea of the memory requirements of a big Sage server. > > smap and pmap comes to mind. Some pointers to get started: > > * > http://virtualthreads.blogspot.com/2006/02/understanding-memory-usage-on-linux.html > * http://bmaurer.blogspot.com/2006/03/memory-usage-with-smaps.html > > The slashdot discussion at > > * http://it.slashdot.org/article.pl?sid=06/02/06/120210 > > also has some lively discussion, but the signal to noise ratio is > pretty bad or normal for slashdot :) > > Note that smap has Python binding for Linux, so we might want to > consider using that optionally since not every kernel supports it, > even though on modern system I would guess it will be hard to find one > that doesn't. > > In general we are using crappy interfaces to measure memory > consumption from Sage, i.e. get_memory_usage(). We are even parsing > the output from "top" on non-Linux platforms!
Sage uses /proc/pid/status on Linux. I don't know if this is "crappy" or not; it's code that I got from http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/286222 Python Cookbook, by Jean Brouwers On OSX, indeed it just naively reads top, which is... well just as good or bad as top at reporting a valid number. I don't know whether OS X top is sensible or not, though I don't see why it would be wrong. William --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
