smem is a tool that can give numerous reports on memory usage on Linux systems. Unlike existing tools, smem can report proportional set size (PSS), which is a more meaningful representation of the amount of memory used by libraries and applications in a virtual memory system.
Because large portions of physical memory are typically shared among multiple applications, the standard measure of memory usage known as resident set size (RSS) will significantly overestimate memory usage. PSS instead measures each application's "fair share" of each shared area to give a realistic measure.
smem has many features:
- system overview listing
- listings by process, mapping, user
- filtering by process, mapping, or user
- configurable columns from multiple data sources
- configurable output units and percentages
- configurable headers and totals
- reading live data from /proc
- reading data snapshots from directory mirrors or compressed tarballs
- lightweight capture tool for embedded systems
- built-in chart generation
smem has a few requirements:
- a reasonably modern kernel (> 2.6.27 or so)
- a reasonably recent version of Python (2.4 or so)
- the matplotlib library for chart generation (optional, auto-detected)
Sample output
Here are some smem graphs showing how RSS exaggerates memory usage. Note how apps that share libraries are over-reported on the RSS side and nearly vanish on the PSS side. The X server is also shares memory heavily, it's real memory usage is about 5 times smaller.
Using smem
Show basic process information | smem |
Show library-oriented view | smem -m |
Show user-oriented view | smem -u |
Show system view | smem -R 4G -K /path/to/vmlinux -w |
Show totals and percentages | smem -t -p |
Show different columns | smem -c "name user pss" |
Sort by reverse RSS | smem -s rss -r |
Show processes filtered by mapping | smem -M libxml |
Show mappings filtered by process | smem -m -P [e]volution |
Read data from capture tarball | smem --source capture.tar.gz |
Show a bar chart labeled by pid | smem --bar pid -c "pss uss" |
Show a pie chart of RSS labeled by name | smem --pie name -s rss |
Getting smem
To get the latest release version, click here.
The latest source code can be grabbed from smem's Mercurial repository here with the command:
hg clone http://selenic.com/repo/smem
Feedback
Write to the smem list at [email protected].