Re: [PATCH] add extra free kbytes tunable

[Simon Jeons <simon.jeons@gmail.com>]

On 03/02/2013 06:33 AM, Hugh Dickins wrote:
> On Fri, 1 Mar 2013, Simon Jeons wrote:
>> On 03/01/2013 05:22 PM, Simon Jeons wrote:
>>> On 02/23/2013 01:56 AM, Johannes Weiner wrote:
>>>> Mapped file pages have to get scanned twice before they are reclaimed
>>>> because we don't have enough usage information after the first scan.
>>> It seems that just VM_EXEC mapped file pages are protected.
>>> Issue in page reclaim subsystem:
>>> static inline int page_is_file_cache(struct page *page)
>>> {
>>>      return !PageSwapBacked(page);
>>> }
>>> AFAIK, PG_swapbacked is set if anonymous page added to swap cache, and be
>>> cleaned if removed from swap cache. So anonymous pages which are reclaimed
>>> and add to swap cache won't have this flag, then they will be treated as
>> s/are/aren't
> PG_swapbacked != PG_swapcache

Oh, I see. Thanks Hugh, thanks for your patient. :)

In function __add_to_swap_cache if add to radix tree successfully will 
result in increase NR_FILE_PAGES, why? This is anonymous page instead of 
file backed page.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>