FRSS

Introduction

FRSS is a library for printing the resident set size (RSS) of a Fortran application at runtime. It is MPI-aware and displays the memory information for the corresponding MPI rank. It can also be used to determine the maximum used memory per node.

Usage

Print the RSS

Anywhere in you Fortran code, you can trigger the output by calling the subroutine:

call frss_print()

It will print the following information to stdout:

Abbreviation	Description	Source
RSS	Current resident set size	/proc/self/status
HWM	High water mark of the RSS	/proc/self/status
OOM	Out-of-memory score	/proc/self/oom_score
dt	Elapsed wall-clock time since last call

If you want to display this information only for a specific MPI rank, call (e.g. for rank 0):

call frss_print_rank(0)

You can also display the currently used memory of the node your application is running on by calling:

call frss_print_node()

Monitor memory consumption of a node

To determine the high water mark of the used memory per node, you need to start the measurement first providing the desired time sampling. For extracting the memory information every 1000 milliseconds, for example, call:

call frss_monitor_node(1000)

Before your application finishes, print the measured data with:

call frss_print_node()

The output contains the following information:

Label	Description	Source
Total	Total usable memory	/proc/meminfo
Used (now)	Currently used memory	/proc/meminfo
Used (initial)	Used memory when frss_monitor_node was called	/proc/meminfo
Used (max)	Maxmimum of used memory during measurement	/proc/meminfo

Link with FRSS

In order to use FRSS, you need to link with the library, e.g. by using the following flags: -L/path/to/frss -lfrss.

License

GPLv3