[Mono-devel-list] USE_MMAP speed/time tradeoff

[Ben Maurer]

On Sat, 2005-08-06 at 23:26 +0200, Michal Moskal wrote:
> Hello,
> 
> I noticed slowdown in Nemerle compiler with:
> 
> 2005-06-20 Gonzalo Paniagua Javier <gonzalo at ximian.com>
> 
>         * configure.in: enabled the use of mmap/munmap for solaris and linux.
>         It seems to help with memory usage.
> 
> With this patch the compiler is about 10% slower, but uses around 10%
> less memory. This is all on amd64 box, running 64 bit version of mono.
> 
> The Nemerle compiler is quite allocation intensive. The working set is about 
> 140M and the running time is about 23s.
> 
> I wonder if:
>   a) we can introduce --with-mmap configure switch?
>   b) better yet, make the mmap version go as fast as the brk one?

Any differences in the oprofile output? Can you try on x86?

10% is a fairly large performance regression. Also, Gonzalo was trying
to work on the "large file upload" setup, which has better solutions
(buffering to files, like is done in Whidbey).

-- Ben