Hello,
On Wed, Sep 28, 2016 at 05:31:03PM +0800, ming.ling wrote:
> Non-lru pages don't belong to any lru, so accounting them to
> NR_ISOLATED_ANON or NR_ISOLATED_FILE doesn't make any sense.
> It may misguide functions such as pgdat_reclaimable_pages and
> too_many_isolated.
I agree this part. It would be happier if you give any story you suffered
from. Although you don't have, it's okay because you are correcting
clearly wrong part. Thanks. :)
>
> This patch adds NR_ISOLATED_NONLRU to vmstat and moves isolated non-lru
> pages from NR_ISOLATED_ANON or NR_ISOLATED_FILE to NR_ISOLATED_NONLRU.
> And with non-lru pages in vmstat, it helps to optimize algorithm of
> function too_many_isolated oneday.
Need more justfication to add new vmstat because once we add it, it's
really hard to change/remove it(i.e., maintainace trobule) so I want
to add it when it really would be helpful sometime, not now.
Could you resend the patch without part adding new vmstat?
Thanks.
>
> Signed-off-by: ming.ling <ming.ling@xxxxxxxxxxxxxx>
> ---
> include/linux/mmzone.h | 1 +
> mm/compaction.c | 12 +++++++++---
> mm/migrate.c | 14 ++++++++++----
> 3 files changed, 20 insertions(+), 7 deletions(-)
>
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index 7f2ae99..dc0adba 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -169,6 +169,7 @@ enum node_stat_item {
> NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */
> NR_DIRTIED, /* page dirtyings since bootup */
> NR_WRITTEN, /* page writings since bootup */
> + NR_ISOLATED_NONLRU, /* Temporary isolated pages from non-lru */
> NR_VM_NODE_STAT_ITEMS
> };
>
> diff --git a/mm/compaction.c b/mm/compaction.c
> index 9affb29..8da1dca 100644
> --- a/mm/compaction.c
> +++ b/mm/compaction.c
> @@ -638,16 +638,21 @@ isolate_freepages_range(struct compact_control *cc,
> static void acct_isolated(struct zone *zone, struct compact_control *cc)
> {
> struct page *page;
> - unsigned int count[2] = { 0, };
> + unsigned int count[3] = { 0, };
>
> if (list_empty(&cc->migratepages))
> return;
>
> - list_for_each_entry(page, &cc->migratepages, lru)
> - count[!!page_is_file_cache(page)]++;
> + list_for_each_entry(page, &cc->migratepages, lru) {
> + if (PageLRU(page))
> + count[!!page_is_file_cache(page)]++;
> + else
> + count[2]++;
> + }
>
> mod_node_page_state(zone->zone_pgdat, NR_ISOLATED_ANON, count[0]);
> mod_node_page_state(zone->zone_pgdat, NR_ISOLATED_FILE, count[1]);
> + mod_node_page_state(zone->zone_pgdat, NR_ISOLATED_NONLRU, count[2]);
> }
>
> /* Similar to reclaim, but different enough that they don't share logic */
> @@ -659,6 +664,7 @@ static bool too_many_isolated(struct zone *zone)
> node_page_state(zone->zone_pgdat, NR_INACTIVE_ANON);
> active = node_page_state(zone->zone_pgdat, NR_ACTIVE_FILE) +
> node_page_state(zone->zone_pgdat, NR_ACTIVE_ANON);
> + /* Is it necessary to add NR_ISOLATED_NONLRU?? */
> isolated = node_page_state(zone->zone_pgdat, NR_ISOLATED_FILE) +
> node_page_state(zone->zone_pgdat, NR_ISOLATED_ANON);
>
> diff --git a/mm/migrate.c b/mm/migrate.c
> index f7ee04a..cd5abb2 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -168,8 +168,11 @@ void putback_movable_pages(struct list_head *l)
> continue;
> }
> list_del(&page->lru);
> - dec_node_page_state(page, NR_ISOLATED_ANON +
> - page_is_file_cache(page));
> + if (PageLRU(page))
> + dec_node_page_state(page, NR_ISOLATED_ANON +
> + page_is_file_cache(page));
> + else
> + dec_node_page_state(page, NR_ISOLATED_NONLRU);
> /*
> * We isolated non-lru movable page so here we can use
> * __PageMovable because LRU page's mapping cannot have
> @@ -1121,8 +1124,11 @@ out:
> * restored.
> */
> list_del(&page->lru);
> - dec_node_page_state(page, NR_ISOLATED_ANON +
> - page_is_file_cache(page));
> + if (PageLRU(page))
> + dec_node_page_state(page, NR_ISOLATED_ANON +
> + page_is_file_cache(page));
> + else
> + dec_node_page_state(page, NR_ISOLATED_NONLRU);
> }
>
> /*
> --
> 1.9.1
>
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