Re: swappiness=0 makes software suspend fail.

[Nick Piggin <nickpiggin@yahoo.com.au>]

Pavel Machek wrote:
> Hi!
> 
> Andrew, in 2.6.6 shrink_all_memory() does not work if swappiness ==
> 0. shrink_all_memory() calls balance_pgdat(), that calls
> shrink_zone(), and that calls refill_inactive_zone(), which looks at
> swappiness.
> 
> Additional parameter to all these calls neutralizing swappiness would
> help, as would temporarily setting swappiness to 100 in
> shrink_all_memory. Is there a less ugly solution?

I have a cleanup patch that allows this sort of thing to easily
be passed into the lower levels of reclaim functions. I don't
know if it would be to Andrew's taste though...

It basically replaces all function parameters in vmscan.c with

struct scan_control {
	unsigned long nr_to_scan;
	unsigned long nr_scanned;
	unsigned long nr_reclaimed;
	unsigned int gfp_mask;
	struct page_state ps;
	int may_writepage;
};

So you could easily add a field for swsusp.

Until something like this goes through, please don't fuglify
vmscan.c any more than it is... do the saving and restoring
thing that Nigel suggested please.