Re: [PACTH v2 0/3] Implement /proc/<pid>/totmaps

From: Michal Hocko
Date: Mon Aug 22 2016 - 03:41:17 EST


On Mon 22-08-16 09:07:45, Minchan Kim wrote:
[...]
> #!/bin/sh
> ./smap_test &
> pid=$!
>
> for i in $(seq 25)
> do
> awk '/^Rss/{rss+=$2} /^Pss/{pss+=$2} END {}' \
> /proc/$pid/smaps
> done
> kill $pid
>
> root@bbox:/home/barrios/test/smap# time ./s.sh
> pid:21973
>
> real 0m17.812s
> user 0m12.612s
> sys 0m5.187s

retested on the bare metal (x86_64 - 2CPUs)
Command being timed: "sh s.sh"
User time (seconds): 0.00
System time (seconds): 18.08
Percent of CPU this job got: 98%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:18.29

multiple runs are quite consistent in those numbers. I am running with
$ awk --version
GNU Awk 4.1.3, API: 1.1 (GNU MPFR 3.1.4, GNU MP 6.1.0)

> > like a problem we are not able to address. And I would even argue that
> > we want to address it in a generic way as much as possible.
>
> Sure. What solution do you think as generic way?

either optimize seq_printf or replace it with something faster.

--
Michal Hocko
SUSE Labs