Re: is_head_of_free_region slowing down swsusp

[Nigel Cunningham]

Hi Pavel.

On Fri, 2004-08-13 at 08:23, Pavel Machek wrote:
> is_head_of_free_region with count_and_copy_zone results results in
> pretty nasty O(number_of_free_regions^2) behaviour, and some users see
> cpu spending 40 seconds there :-(.
> 
> Actually count_and_copy_zone would probably be happy with
> "is_free_page()".

Take a look at my implementation. I do a one-time pass through the slow
path, building a bitmap of free pages. is_head_of_free_region is then
simply a O(1) loop through the bitmap.

Nigel
-- 
Nigel Cunningham
Christian Reformed Church of Tuggeranong
PO Box 1004, Tuggeranong, ACT 2901

Many today claim to be tolerant. But true tolerance can cope with others
being intolerant.

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