Re: [PATCH] Faster SWSUSP free page counting

[Nigel Cunningham <ncunningham@clear.net.nz>]

Hi.

The speed difference depends of course upon the number of pages free and
the degree of fragmentation. I guess the easy answer is that it was
written and kept because it helped. Having talked to Andrew about the
use of page flags, I'll do some more changes before we put it to Linus -
I'll use a dynamically allocated bitmap instead of pageflags.

Regards,

Nigel

On Tue, 2003-03-18 at 20:20, Pavel Machek wrote:
> Hi!
> 
> > This patch improves the speed of SWSUSP's count_and_copy_data_pages
> > function by generating a map of the free pages before iterating through
> > the list of pages. The net result is to go from O(n^2) to O(n), if I
> > remember my computer science correctly.
> 
> Is the speed difference noticable?
> 
> If yes than okay, but generate_free_page_map() should still be moved
> into kernel/suspend.c.
> 								Pavel
-- 
Nigel Cunningham
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