Re: swap space: an idea. Please comment.

mcculley@iag.net
Mon, 24 Feb 1997 07:37:46 -0500


Actually, I have been thinking about this topic for a while. My
problem is that I have an application that we develop under Linux.
This application consists of ~800,000 lines of C code. Under certain
debugging configurations, it can consume huge amounts of virtual
memory. Also, sometimes it is necessary to use two or more
development source trees together when integrating changes. This can
take up to 750 MB per compiled tree. So, I often find myself creating
and destroying swap files to accomodate the mode I am in at the
moment.

The solution I was thinking of is adding a hook to the VFS layer so
that filesystems can offer the kernel free swap pages on demand. This
would be better than swap files, since less maintenance and accounting
need be done on pages that are to be cleansed on reboot. It would
increase your virtual memory size to be your RAM plus all swap
partitions plus all of the free pages on all of the filesystems that
support this operation. One could add options to the filesystem to
control what percentage of available space to be offered or what
amount to leave available for normal files.

And I would not have to dink around with swap files any more.

-- 
Gene McCulley    mcculley@iag.net    http://www.iag.net/~mcculley