[Patch, gfortran]: PR21820, 23363 etc.: chuck mmap

[Janne Blomqvist]

On Sat, Sep 03, 2005 at 09:23:52PM +0300, Janne Blomqvist wrote:
> Timing measurements on Linux-x86 for this patch:
> 
> PR 21820
> 
> No mmap:
> 
> ./pr21820.gfortran_no_mmap  0,02s user 0,00s system 82% cpu 0,024 total
> 
> mmap (current HEAD):
> 
> ./pr21820.gfortran  0,16s user 0,40s system 102% cpu 0,547 total
> 
> delete file before executing for HEAD:
> 
> ./pr21820.gfortran  0,02s user 0,01s system 134% cpu 0,022 total

> 
> PR 23363
> 
> no mmap:
> 
> ./rdiska.gfortran_no_mmap  0,75s user 0,01s system 98% cpu 0,774 total
> 
> with mmap (HEAD):
> 
> ./rdiska.gfortran  4,11s user 9,38s system 99% cpu 13,560 total
> 
> delete file before running HEAD:
> 
> ./rdiska.gfortran  0,94s user 0,03s system 97% cpu 0,990 total

As to why HEAD is much faster when first deleting the file, it turns
out that when the file needs to be extended the library switches to
the fd method. Doh.. 

Sorry for any potential confusion.

-- 
Janne Blomqvist