Re: High memory usage on // substitution in one situation, normal usage in other

[Christian Neukirchen <chneukirchen@xxxxxxxxx>]

Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx> writes:

> On May 22,  8:50am, Daniel Shahaf wrote:
> }
> } > 1.8MB/2*(the number of zeroes in all integers from 1 to 200000),
> } 
> }     88894
> } 
> } (So we can compute the exact predicted memory use and compare it to the
> } observed use.)
>
> I'd be surprised to find that anyone has a machine with 80GB of virtual
> memory that it's worth dedicating to testing this.  (Also that's a really
> rough estimate, could be low by as much as a factor of six.)

Challenge accepted. ;)  (The machine idles anyway...)

Linux deka 4.4.0-78-generic #99-Ubuntu SMP Thu Apr 27 15:29:09 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

zsh 5.1.1 (x86_64-ubuntu-linux-gnu) with EXTENDEDGLOB on:

  PID USER      PRI - -  NI  VIRT   RES   SHR S CPU% MEM%   TIME+  Command
 2841 neukirche  20 - -   0 81.4G 77.7G  3064 R 99.8 58.1  8:05.40 zsh big
 2841 neukirche  20 - -   0 82.1G 75.9G  2872 R 18.5 56.8  8:26.14 zsh big
 2841 neukirche  20 - -   0 87.7G 80.8G  2872 R 99.8 60.5  9:58.80 zsh big
 2841 neukirche  20 - -   0 91.2G 84.3G  2872 R 99.7 63.1 11:01.29 zsh big
 2841 neukirche  20 - -   0 93.5G 85.3G  2872 R 100. 63.8 11:54.64 zsh big
 2841 neukirche  20 - -   0   95G 85.7G  2872 R 99.7 64.1 12:49.51 zsh big
 2841 neukirche  20 - -   0   97G 86.2G  2872 R 99.7 64.5 13:45.90 zsh big
 2841 neukirche  20 - -   0  100G 86.8G  2872 R 99.7 65.0 15:14.28 zsh big
 2841 neukirche  20 - -   0  102G 87.4G  2664 R 100. 65.4 16:24.38 zsh big
 2841 neukirche  20 - -   0  105G 88.0G  2664 R 99.7 65.9 17:45.16 zsh big
 2841 neukirche  20 - -   0  107G 88.8G  2664 R 99.0 66.4 19:09.09 zsh big
 2841 neukirche  20 - -   0  109G 89.3G  2664 R 99.5 66.8 20:26.41 zsh big
 2841 neukirche  20 - -   0  116G 93.5G  2664 R 99.0 70.0 24:52.41 zsh big
 2841 neukirche  20 - -   0  118G 92.5G  2664 D 43.4 69.3 27:12.57 zsh big
 2841 neukirche  20 - -   0  122G   95G  2664 R 100. 71.4 30:23.67 zsh big
 2841 neukirche  20 - -   0  128G   98G  2664 R 30.8 73.7 39:08.38 zsh big
 2841 neukirche  20 - -   0  132G  101G  2640 R 99.7 75.7 47:25.95 zsh big

Then the box started to swap as it only has 134G RAM, and I stopped it.

Perhaps the result is interesting nevertheless.

-- 
Christian Neukirchen  <chneukirchen@xxxxxxxxx>  http://chneukirchen.org