On 2020년 04월 22일 22:07, Johannes Weiner wrote:
> On Wed, Apr 22, 2020 at 05:48:15PM +0900, Jaewon Kim wrote:
>> @@ -1295,11 +1295,15 @@ static unsigned long shrink_page_list(struct list_head *page_list,
>> */
>> if (page_mapped(page)) {
>> enum ttu_flags flags = ttu_flags | TTU_BATCH_FLUSH;
>> + bool lazyfree = PageAnon(page) && !PageSwapBacked(page);
>>
>> if (unlikely(PageTransHuge(page)))
>> flags |= TTU_SPLIT_HUGE_PMD;
>> +
>> if (!try_to_unmap(page, flags)) {
>> stat->nr_unmap_fail += nr_pages;
>> + if (lazyfree && PageSwapBacked(page))
> This looks pretty strange, until you remember that try_to_unmap()
> could SetPageSwapbacked again.
>
> This might be more obvious?
>
> was_swapbacked = PageSwapBacked(page);
> if (!try_to_unmap(page, flags)) {
> stat->nr_unmap_fail += nr_pages;
> if (!was_swapbacked && PageSwapBacked(page))
Hello Johannes, thank you for your comment.
The name can changed from layzyfree to was_swapbacked.
By the way, did you mean removing PageAnon(page), too? It seems to be OK, though.
>> + stat->nr_lazyfree_fail += nr_pages;
>> goto activate_locked;
> Or at least was_lazyfree.
Sorry but I'm confused.
I think you meant additional comment to previous your comment
rather than you wanted to rename stat->nr_lazyfree_fail to stat->was_lazyfree.
>
>> @@ -1491,8 +1495,8 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone,
>> .priority = DEF_PRIORITY,
>> .may_unmap = 1,
>> };
>> - struct reclaim_stat dummy_stat;
>> - unsigned long ret;
>> + struct reclaim_stat stat;
>> + unsigned long reclaimed;
> nr_reclaimed would be better.
I will add nr_ prefix on next patch.
>
> I also prefer keeping dummy_stat, since that's still what it is.
This patch uses stat.nr_lazyfree_fail, I do not understand why it is still dummy_stat.
If you want, I will keep dummy_stat, though.
Thank you
Jaewon Kim
>
>
