[PATCH 00/14] Present useful limits to user (v2)

[Balbir Singh]

On Fri, Jul 15, 2016 at 01:35:47PM +0300, Topi Miettinen wrote:
> Hello,
> 
> There are many basic ways to control processes, including capabilities,
> cgroups and resource limits. However, there are far fewer ways to find out
> useful values for the limits, except blind trial and error.
> 
> This patch series attempts to fix that by giving at least a nice starting
> point from the highwater mark values of the resources in question.
> I looked where each limit is checked and added a call to update the mark
> nearby.
> 
> Example run of program from Documentation/accounting/getdelauys.c:
> 
> ./getdelays -R -p `pidof smartd`
> printing resource accounting
> RLIMIT_CPU=0
> RLIMIT_FSIZE=0
> RLIMIT_DATA=18198528
> RLIMIT_STACK=135168
> RLIMIT_CORE=0
> RLIMIT_RSS=0
> RLIMIT_NPROC=1
> RLIMIT_NOFILE=55
> RLIMIT_MEMLOCK=0
> RLIMIT_AS=130879488
> RLIMIT_LOCKS=0
> RLIMIT_SIGPENDING=0
> RLIMIT_MSGQUEUE=0
> RLIMIT_NICE=0
> RLIMIT_RTPRIO=0
> RLIMIT_RTTIME=0
> 
> ./getdelays -R -C /sys/fs/cgroup/systemd/system.slice/smartd.service/
> printing resource accounting
> sleeping 1, blocked 0, running 0, stopped 0, uninterruptible 0
> RLIMIT_CPU=0
> RLIMIT_FSIZE=0
> RLIMIT_DATA=18198528
> RLIMIT_STACK=135168
> RLIMIT_CORE=0
> RLIMIT_RSS=0
> RLIMIT_NPROC=1
> RLIMIT_NOFILE=55
> RLIMIT_MEMLOCK=0
> RLIMIT_AS=130879488
> RLIMIT_LOCKS=0
> RLIMIT_SIGPENDING=0
> RLIMIT_MSGQUEUE=0
> RLIMIT_NICE=0
> RLIMIT_RTPRIO=0
> RLIMIT_RTTIME=0

Does this mean that rlimit_data and rlimit_stack should be set to the
values as specified by the data above?

Do we expect a smart user space daemon to then tweak the RLIMIT values?

Balbir Singh.