Re: large files and low memory

On Tue, 5 Oct 2010, Enrico Weigelt wrote:

* Shawn Pearce [off-list ref] wrote:

quoted

The mmap() isn't the problem.  Its the allocation of a buffer that is
larger than the file in order to hold the result of deflating the file
before it gets written to disk.  
When the file is bigger than physical memory, the kernel has to
page in parts of the file as well as swap in and out parts of
that allocated buffer to hold the deflated file.

What are the access pattern of these memory areas ?

Perfectly linear.

Perhaps madvise() could help ?

Perhaps.


Nicolas