The documentation is in
Documentation/filesystems/proc.txt in the kernel source. Many distributions make it available through a package (e.g.
linux-doc under Ubuntu, installing files under
Here's the description of the
statm fields from the documentation:
size total program size (pages) (same as VmSize in status)
resident size of memory portions (pages) (same as VmRSS in status)
shared number of pages that are shared (i.e. backed by a file)
trs number of pages that are 'code' (not including libs; broken, includes data segment)
lrs number of pages of library (always 0 on 2.6)
drs number of pages of data/stack (including libs; broken, includes library text)
dt number of dirty pages (always 0 on 2.6)
This process has 954 pages in RAM. A page is 4kB on your system (it can be other values on exotic architectures or configurations;
getconf PAGESIZE would confirm it). So that's a bit under 4MB.
The documentation isn't exhaustive. If you can't find what you're looking for, try searching on the Linux Weekly News or elsewhere on the web. If you still can't find the answer, use the source.