Re: [PATCH] Reap dead swap cache earlier v2

[John Stoffel]

Marcelo> As suggested by Linus, I've cleaned the reapswap code to be
Marcelo> contained inside an inline function. (yes, the if statement
Marcelo> is really ugly)

Shouldn't the "swap_count(page) == 1" check be earlier in the if
statement, so we can fall through more quickly if there is no work to
be done?  A small optimization, but putting the common cases first
will help.

Marcelo> +static inline int clean_dead_swap_page (struct page* page)
Marcelo> +{
Marcelo> +	int ret = 0;
Marcelo> +	if (!TryLockPage (page)) { 
Marcelo> +		if (PageSwapCache(page) && PageDirty(page) &&
Marcelo> +				(page_count(page) - !!page->buffers) == 1 &&
Marcelo> +				swap_count(page) == 1) { 
Marcelo> +			ClearPageDirty(page);
Marcelo> +			ClearPageReferenced(page);
Marcelo> +			page->age = 0;
Marcelo> +			ret = 1;
Marcelo> +		}

Thanks,
John
   John Stoffel - Senior Unix Systems Administrator - Lucent Technologies
	 [e-mail] - http://www.lucent.com - 978-952-7548