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@netj /memusg
Last active Sep 1, 2016

memusg -- Measure memory usage of processes
#!/usr/bin/env bash
# memusg -- Measure memory usage of processes
# Usage: memusg COMMAND [ARGS]...
#
# Author: Jaeho Shin <netj@sparcs.org>
# Created: 2010-08-16
############################################################################
# Copyright 2010 Jaeho Shin. #
# #
# Licensed under the Apache License, Version 2.0 (the "License"); #
# you may not use this file except in compliance with the License. #
# You may obtain a copy of the License at #
# #
# http://www.apache.org/licenses/LICENSE-2.0 #
# #
# Unless required by applicable law or agreed to in writing, software #
# distributed under the License is distributed on an "AS IS" BASIS, #
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. #
# See the License for the specific language governing permissions and #
# limitations under the License. #
############################################################################
set -um
# check input
[[ $# -gt 0 ]] || { sed -n '2,/^#$/ s/^# //p' <"$0"; exit 1; }
# TODO support more options: peak, footprint, sampling rate, etc.
pgid=$(ps -o pgid= $$)
# make sure we're in a separate process group
if [[ "$pgid" == "$(ps -o pgid= $(ps -o ppid= $$))" ]]; then
cmd=
set -- "$0" "$@"
for a; do cmd+="'${a//"'"/"'\\''"}' "; done
exec bash -i -c "$cmd"
fi
# detect operating system and prepare measurement
case $(uname) in
Darwin|*BSD) sizes() { /bin/ps -o rss= -g $1; } ;;
Linux) sizes() { /bin/ps -o rss= -$1; } ;;
*) echo "$(uname): unsupported operating system" >&2; exit 2 ;;
esac
# monitor the memory usage in the background.
(
peak=0
while sizes=$(sizes $pgid)
do
set -- $sizes
sample=$((${@/#/+}))
let peak="sample > peak ? sample : peak"
sleep 0.1
done
echo "memusg: peak=$peak" >&2
) &
monpid=$!
# run the given command
exec "$@"
@brassel

Hi Jaeho Shin,

Thanks for your easy to use tool!
I would like to use your script for a series of benchmarks and I would like to get the output for each benchmark separately. But somehow all peaks get printed after the whole suite is finished. Can I do something about this?

Cheers
Bernd

@netj
Owner

Hi brassel,
I'm so glad to meet a fan of my tool :)

I think you just pointed out a caveat of my script.
This script monitors the rss peak of all processes in the same process group which shares a PGID.
It seems you're running all the benchmarks with this tool within a single shell script, right?
Since processes launched from a non-interactive shell usually uses the same PGID, this tool won't work correctly.
I only considered using this from an interactive shell, but I should fix this limitation as I'll encounter a similar case soon.

For the moment, you can launch each benchmark prefixing it with setsid:
setsid memusg ./benchmark-XYZ ...
Or, if setsid isn't available on your system, then using bash -i (makes a little clutter):
bash -i -c 'memusg ./benchmark-XYZ ...'

Thanks for your feedback!
~Jaeho

@brassel

Thank you very much for the fast answer!
Using "setsid" worked like a charm.

Thankful Greetings,
Bernd

@netj
Owner

Bernd, I actually updated the script an hour ago so we can now use it without the workaround. :)

@brassel

As I have read your comments in the script

# TODO support more options: peak, footprint, sampling rate, etc.

I thought you might be interested that for my purposes I have changed by hand

  • the sampling rate
  • the redirection of the resulting output to &2

Everything else was just as needed.
Bernd

@brassel

One thing I notice is that I do not seem to be able to stop processes with ^C while using memusg.
What might be the reason for this?

@XICO2KX

Hello!
I have a problem using your tool with a multi-threaded program...

This last program when started launches itself a couple of times.
(Different processes with different PIDs but with the same name appear on "top".)

I am using a shell script to launch "memusg". Something like:
[script.sh] memusg.sh command

And I run it through "nohup":
nohup script.sh &

But by watching "top", the command itself isn't executed!
(Or it shows up and quickly disappears constantly!)

And the output file shows multiple times:
[nohup.out] bash: no job control in this shell

The only processes that I can see running are:
/bin/bash script.sh
bash memusg.sh command

But if I kill the process (the one initiated by "nohup"):
/bin/bash script.sh
the command gets executed!

Do you know what is the problem and how can I fix it?
Thank you very much!

@dbolser

Sorry for being dumb... what is the output? kb? Cheers,
Dan.

@netj
Owner

@brassel and @XICO2KX I know it's very late, but I'll look into this problem. It seems there're quite a few folks who want to use this in various ways.

@gbluma

+1 Just used this for some quick profiling. Thanks.

@nderevj

Nice work! I used this script to do some quick profiling of some PHP scripts.

@XICO2KX

Just a heads up...
User Jonathan Clark has a reviewed and improved version of this memusg script here:
https://github.com/jhclark/memusg
It seems to have fixed all the problems with child processes, threads and nohup.
The only disadvantage is that it measures the Virtual Size instead.
But you only need to change the expression 'vsize=' to 'rssize=' to get the Peak (High Water Mark) RSS Memory Usage.

@kilburn

Just FYI, the version linked by @XICO2KX does not work on OSX/BSD (due to differences in the ps binary).

@Garonenur

has anyone an idea, what I can do if I have to log a software that only works like this:

executable parameter parameter < input

I could adapt the script, so it only works with that tool and pass the input as a normal parameter, and instead of "just" calling $@ split the arguments and construct the correct call. But I like these kind of monitoring tools to work more generic.

for example if I type

/usr/bin/time -v sort < unsorted_file

I get the sorted output as expected. If I do the same with your script, it does not work

@Garonenur

I found the answer:

exec "$@" <&0

should pass the stdin to the command

@dbohdan

Hi, @netj! I'm a fan of your script and have been using it for a long time. I want to include it in my repository, https://github.com/tclssg/benchmark-data, to be run from a benchmarking script. Could you state what license it is distributed under?

@holtgrewe

I second the question of @dbohdan. @netj, what is the license here? MIT? Public domain?

@jvollme

Hi, i'm trying to use this script to monitor peak RAM usage of scripts I'm running withing an SGE environment on a shared server (using qsub). I've found your script useful and easy to use , so i decided to use it here.
However, the SGE-jobs always fail when I try to run "memusg" with the following error message:
bash: no job control in this shell
'': unknown terminal type.

memusg only works if i run it in a local shell (NOT submiting it via qsub) which sadly is not an option for the jobs i want to run.
Is there a way to fix this?

@netj
Owner

@dbohdan @holtgrewe: Thanks for asking! Didn't know this was being used by so many people. I just added the license (Apache 2.0) to the script. You are free to use/include/modify it. Looks like I should try to iron out the issues raised here and there.

@tantrev

Fantastic tool! Use it quite frequently to profile programs for parallelization. I noticed that sending it to background with a terminating "&" seems to cause problems - in particular, it always closes my shell session. Would it be too difficult to make memusg compatible with background execution? :P

@EmilStenstrom
EmilStenstrom commented May 15, 2016 edited

Can I suggest this is moved to an actual repository instead of just a gist? Would make it possible to send pull requests and create issues properly.

@mbland

FWIW, though it's nearly six years since @brassel asked his first question, just yesterday I wrestled with an issue whereby memusg was hanging in a driver script. I have an extensive comment in my script explaining the issue with bash -i -c "$cmd" causing my script to hang, and how job control (set -m) solves the problem. An answer to Why can't I use job control in a bash script? helped me zero in on the set -m solution.

A reproduction, per my comment:

First create the following script; I'll call it foo.sh:

memusg ls >"foo0.out" 2>&1
memusg ls >"foo1.out" 2>&1

Then:

  • Run it as bash foo.sh and it will hang; run fg to continue.
  • Run it as bash -m foo.sh and it will complete.

Also try editing the output redirections per the following and running it with bash foo.sh:

  • Remove the first 2>&1 redirection and it will hang.
  • Remove the second 2>&1 redirection and it will complete.
  • Remove both 2>&1 redirection and it will complete.
  • Remove the first >"foo0.out" redirection and it will hang.
  • Remove the second >"foo0.out" redirection and it will complete.

I also validated the fact that set -m obviated the need for a new process group by adding the following to memusg before the exec bash -i -c "$cmd" call, then watched when it appeared (bash) and when it didn't (bash -m or set -m):

echo "EXECING FOR NEW PROCESS GROUP" >&2
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