Re: Limit memory consumption of an ad hoc process

[Greg Wooledge <greg@wooledge.org>]

On Mon, Jul 05, 2021 at 10:15:19AM +0700, Victor Sudakov wrote:
> FreeBSD has a simple way to run some ad-hoc program with memory limits:
> 
> $ limits -m 2G ./mytest
>   memoryuse             2097152 kB
>   vmemoryuse           infinity kB
> $ limits -m 1G ./mytest
>   memoryuse             1048576 kB
>   vmemoryuse           infinity kB
> 
> How do I do the same in Linux (without root permissions)?

One way would be:

(ulimit -m 2097152; ./mytest)

This assumes you're using bash as your shell.

You might want to review the resource limits and how they work --
see setrlimit(2) for the kernel's documentation.  See "help ulimit"
for bash's brief-form documentation.  The longer documentation is in
the bash(1) man page.

You never need root privileges to *reduce* one of your resource limits
to a lower value.  Nor do you need root privs to raise your soft limit
up to the hard limit.  However, you do need root privs to raise your
hard limit.