Subject: Re: bug#79074: 31.0.50; Increase gc-cons-percentage in Makefiles

From: Stefan Monnier <[email-masked]>
Date: Sat, 26 Jul 2025 11:14:48 -0400

> For fun, I also recorded the times for individual compilation processes.
> Here a scatter plot of the result:

Nice, thanks!

> Some statistics:
>
>  gc-cons-percentage │ variable  mean       min      median   max    
> ────────────────────┼───────────────────────────────────────────────
>                 0.1 │ real      1.3452     0.12     0.48     162.52 
>                 0.1 │ rssmax    51622.8    42692    45388.0  641880 
> 		      │
>                0.75 │ real      0.660551   0.1      0.285    69.69  
>                0.75 │ rssmax    54213.1    43032    47932.0  706240 
> 	              │
>                 1.5 │ real      0.507625   0.08     0.22     62.93  
>                 1.5 │ rssmax    60135.5    43060    55508.0  766348 

What kind of "mean" is that?  I think an arithmetic mean doesn't make
much sense for such values, so I hope it was a geometric mean.
Maybe the quartiles would be handy as well.

The rssmax increase from 0.75 to 1.5 suggests that 1.5 is reaching the
limit of the "free gains", but the reduction in real time shows there is
still a gain (in comparison the rssmax increase from 0.1 to 0.75 is
small enough that the real time reduction can be considered a "free
gain").

        Stefan