[maemo-developers] [maemo-developers] swapfile is a huge improvement!

[From: Juha Yrjölä]

On Sat, 2006-01-14 at 11:55 -0500, ext Vladislav Grinchenko wrote:

> with swap on, what happens to the system when you manually remove the
> mmc card? Or when you connect the USB cable to the unit?

Removing the MMC card will definitely cause Bad Things to happen.  It's
also very tricky to protect against the Bad Things.

The system should listen on the MMC cover events, and turn off swap
whenever the MMC cover is opened (which means we have a risk of the card
departing).  Then the system should hurry to swap in all the pages on
the MMC partition, which can take a *long* time depending on the amount
of pages on swap.  Then, most likely, physical memory would run out.  At
that point we are in a very bad situation indeed, if pages from some
critical system processes are still swapped out.

USB Mass Storage is not a problem if the swap resides on a separate
partition.

Cheers,
Juha