[oi-dev] Memory use with Firefox

[Matthew R. Trower]

On 1/4/24 10:54, gary_mills at fastmail.fm (Gary Mills) wrote:

> I still have questions about the memory usage of firefox.  Here's how
> memory size looked after 14 days:
> 
>      <mills at ryzen:2762>$ prstat -c -s size
>      Please wait...
>         PID USERNAME  SIZE   RSS STATE  PRI NICE      TIME  CPU PROCESS/NLWP
>        1598 mills    2850M 1481M sleep   49    0  26:56:22 0.7% firefox/198
>         941 mills    2558M 2532M sleep   59    0  27:14:03 0.2% Xorg/3
>        1978 mills     578M  272M sleep   59    0   0:03:10 0.0% firefox/25
>       18154 mills     569M  261M sleep   44    0   0:15:33 0.1% firefox/26
>        1868 mills     558M  254M sleep   59    0   0:14:22 0.0% firefox/28
>        1867 mills     414M  158M sleep   59    0   0:10:04 0.0% firefox/24
>        1601 mills     411M  151M sleep   59    0   0:01:01 0.0% firefox/24
>        1602 mills     384M  147M sleep   59    0   0:00:32 0.0% firefox/24
>        1866 mills     360M  124M sleep   59    0   0:09:19 0.0% firefox/24
>       18878 mills     340M  108M sleep   49    0   0:00:01 0.0% firefox/25
>       19646 mills     310M   68M sleep   49    0   0:00:00 0.0% firefox/12
>       19639 mills     310M   69M sleep   59    0   0:00:00 0.0% firefox/12
>       19642 mills     310M   68M sleep   49    0   0:00:00 0.0% firefox/12
>        1604 mills     227M   45M sleep   59    0   0:00:03 0.0% firefox/3
>        1600 mills     227M   44M sleep   59    0   0:00:00 0.0% firefox/4
>      Total: 133 processes, 1323 lwps, load averages: 0.22, 0.23, 0.21


> How much memory does firefox want?

All of it.  Your surrender is foregone and non-negotiable.

Seriously, though, I imagine it's going to be related to the kinds of 
sites you visit, what kind of assets they're sucking down, what kind of 
monster javascript frontends they want to run clientside, etc... 
Firefox basically has Operating System status these days.  I've seen 
individual tabs run anywhere from 32MB to 500MB+ each.

 > Why are there so many firefox processes?  I was expecting one process
 > per tab.  Clearly there are many more.  Why do some of the processes

Just like with an OS, you need a process manager to answer these 
questions.  Unfortunately, you said that yours (about:process) wasn't 
working --- did you ever figure that out?  What if you start Firefox 
from the shell; do you get any debug output when you try to load that 
page?  If you can get it working, it will give you a breakdown of each 
process, including purpose, memory, and cpu usage.  It's basically top.


Firefox is just not going to be slim though, no matter what you do; here 
is mine with two (2!) tabs --- and one of them is about:process!

mtrower at saturn:~$ prstat -p $(pgrep firefox|tr '\n' ','),1306
    PID USERNAME  SIZE   RSS STATE  PRI NICE      TIME  CPU PROCESS/NLWP 

  20545 mtrower  1519M  611M sleep   29    0   0:07:39 0.2% firefox/133
   1306 root      181M   49M sleep   43    0   0:10:39 0.2% Xorg/1
  20551 mtrower    17G  184M sleep   59    0   0:00:38 0.0% firefox/27
  23507 mtrower   311M   63M sleep   59    0   0:00:00 0.0% firefox/12
  20552 mtrower   226M   37M sleep   59    0   0:00:00 0.0% firefox/3
  20549 mtrower   227M   37M sleep   59    0   0:00:00 0.0% firefox/4
  22729 mtrower   403M  158M sleep   59    0   0:00:05 0.0% firefox/27
  23506 mtrower   311M   63M sleep   59    0   0:00:01 0.0% firefox/12
  20550 mtrower   358M  104M sleep   59    0   0:00:06 0.0% firefox/28
  23505 mtrower   310M   63M sleep   59    0   0:00:00 0.0% firefox/12

Total: 10 processes, 259 lwps, load averages: 0.62, 0.91, 0.86


about:processes reports:

Firefox      [601MB]
github.com   [158MB]
   Tab: <the github repo I have open>
Extensions   [184MB]
About pages  [105MB]
   Preloaded New Tab
Utility       [37MB]
   JavaScript Oracle
Network       [37MB]
Preallocated  [63MB]
Preallocated  [63MB]
Preallocated  [63MB]

...and you can see how those line up with prstat reporting.


What's up with your Xorg, though?  2.5GB?  Your display server is nearly 
as fat as your Firefox :O


-- Matthew R. Trower