Re: [MIT-Scheme-devel] [commit f372dae] Don't call OS_free_pages after GC flip. We don't resize the heap and we will be reusing it.

[Joe Marshall]

On Fri, Oct 7, 2011 at 12:29 PM, Taylor R Campbell <address@hidden> wrote:
>   Date: Fri, 7 Oct 2011 12:08:09 -0700
>   From: Joe Marshall <address@hidden>
>
>   >    On Wed, Oct 5, 2011 at 7:50 PM, Taylor R Campbell <address@hidden> 
> wrote:
>   >    > Contrariwise, if I have six Scheme processes that have not freed 
> their
>   >    > unused pages and the OS is constantly swapping, then the whole world
>   >    > gets much, much slower, especially at larger heap sizes.
>
>   Were they all actively computing, or were some of the processes waiting for
>   input?
>
> Some were waiting for input.

The unused pages in a waiting process may remain unused for some time,
in which case it would be a good idea to free up the pages (especially if a GC
just happened).

> The purpose of calling OS_free_pages is to make Scheme behave better
> as a citizen of OSland and avoid bogarting more physical memory than
> it needs, not necessarily to speed up Scheme computations.

Do you use the absolute minimum value for --heap that you can get away with?

-- 
~jrm