mm: fix LRU balancing effect of new transparent huge pages
PATCH RESEND 3/3 mm: fix LRU balancing effect of new transparent huge pages
From: Johannes Weiner <[email protected]>
Currently, THP are counted as single pages until they are split right before being swapped out. However, at that point the VM is already in the middle of reclaim, and adjusting the LRU balance then is useless.
Always account THP by the number of basepages, and remove the fixup from the splitting path.
--- mm/swap.c | 23 +++++++++-------------- 1 file changed, 9 insertions(+), 14 deletions(-)
mm/swap.c +9 -14
@@ -262,14 +262,14 @@ void rotate_reclaimable_page(struct page *page) } } -static void update_page_reclaim_stat (struct lruvec *lruvec, -int file,int rotated) +static void update_page_reclaim_stat (struct lruvec *lruvec,int file, +int rotated,int nr_pages) {struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat; - reclaim_stat->recent_scanned[file]++; + reclaim_stat->recent_scanned[file] += nr_pages;if (rotated) - reclaim_stat->recent_rotated[file]++; + reclaim_stat->recent_rotated[file] += nr_pages; } static void __activate_page(struct page *page, struct lruvec *lruvec,
@@ -288,7 +288,7 @@ static void __activate_page(struct page *page, struct lruvec *lruvec,__count_vm_events (PGACTIVATE , nr_pages);__count_memcg_events (lruvec_memcg (lruvec),PGACTIVATE , nr_pages); -update_page_reclaim_stat (lruvec, file,1 ); +update_page_reclaim_stat (lruvec, file,1 , nr_pages); } }
@@ -546,7 +546,7 @@ static void lru_deactivate_file_fn(struct page *page, struct lruvec *lruvec,__count_vm_events (PGDEACTIVATE , nr_pages);__count_memcg_events (lruvec_memcg (lruvec),PGDEACTIVATE , nr_pages); } -update_page_reclaim_stat (lruvec, file,0 ); +update_page_reclaim_stat (lruvec, file,0 , nr_pages); } static void lru_deactivate_fn(struct page *page, struct lruvec *lruvec,
@@ -564,7 +564,7 @@ static void lru_deactivate_fn(struct page *page, struct lruvec *lruvec,__count_vm_events (PGDEACTIVATE , nr_pages);__count_memcg_events (lruvec_memcg (lruvec),PGDEACTIVATE , nr_pages); -update_page_reclaim_stat (lruvec, file,0 ); +update_page_reclaim_stat (lruvec, file,0 , nr_pages); } }
@@ -590,7 +590,7 @@ static void lru_lazyfree_fn(struct page *page, struct lruvec *lruvec,__count_vm_events (PGLAZYFREE , nr_pages);__count_memcg_events (lruvec_memcg (lruvec),PGLAZYFREE , nr_pages); -update_page_reclaim_stat (lruvec,1 ,0 ); +update_page_reclaim_stat (lruvec,1 ,0 , nr_pages); } }
@@ -899,8 +899,6 @@ EXPORT_SYMBOL(__pagevec_release);void lru_add_page_tail (struct page *page,struct page *page_tail,struct lruvec *lruvec,struct list_head *list) { -const int file =0 ; -VM_BUG_ON_PAGE (!PageHead (page), page);VM_BUG_ON_PAGE (PageCompound (page_tail), page);VM_BUG_ON_PAGE (PageLRU (page_tail), page);
@@ -926,9 +924,6 @@ void lru_add_page_tail(struct page *page, struct page *page_tail,add_page_to_lru_list_tail (page_tail, lruvec, page_lru(page_tail)); } - -if (!PageUnevictable (page)) -update_page_reclaim_stat (lruvec, file,PageActive (page_tail)); }#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
@@ -973,7 +968,7 @@ static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec,if (page_evictable (page)) { lru =page_lru (page);update_page_reclaim_stat (lruvec,page_is_file_lru (page), -PageActive (page)); +PageActive (page), nr_pages);if (was_unevictable)__count_vm_events (UNEVICTABLE_PGRESCUED , nr_pages); }else {
Signature · 1 line
2.27.0.rc0.183.gde8f92d652-goog
Quoted 11 lines · Shakeel Butt
From: Johannes Weiner <[email protected]>
Currently, THP are counted as single pages until they are split right before being swapped out. However, at that point the VM is already in the middle of reclaim, and adjusting the LRU balance then is useless.
Always account THP by the number of basepages, and remove the fixup from the splitting path.
Signed-off-by Johannes Weiner <[email protected]>Signed-off-by Shakeel Butt <[email protected]>
This is now already in mm as part of the "mm: balance LRU lists based on relative thrashing" series that I sent out last week and where it was originally from.
Quoted 11 lines · Johannes Weiner
Quoted 9 lines · Shakeel Butt
From: Johannes Weiner <[email protected]>
Currently, THP are counted as single pages until they are split right before being swapped out. However, at that point the VM is already in the middle of reclaim, and adjusting the LRU balance then is useless.
Always account THP by the number of basepages, and remove the fixup from the splitting path.
Quoted 6 lines
Quoted 2 lines
Signed-off-by Johannes Weiner <[email protected]>Signed-off-by Shakeel Butt <[email protected]>This is now already in mm as part of the "mm: balance LRU lists based on relative thrashing" series that I sent out last week and where it was originally from.
Oh sorry, I missed it.
Andrew Morton
maintainerQuoted 10 lines · On Wed, 27 May 2020 15:41:48 -0400 Johannes Weiner <[email protected]> wrote:
Quoted 9 lines · Shakeel Butt
From: Johannes Weiner <[email protected]>
Currently, THP are counted as single pages until they are split right before being swapped out. However, at that point the VM is already in the middle of reclaim, and adjusting the LRU balance then is useless.
Always account THP by the number of basepages, and remove the fixup from the splitting path.
Quoted 6 lines
Quoted 2 lines
Signed-off-by Johannes Weiner <[email protected]>Signed-off-by Shakeel Butt <[email protected]>This is now already in mm as part of the "mm: balance LRU lists based on relative thrashing" series that I sent out last week and where it was originally from.
Yup. I hope [1/3] and [2/3] weren't urgent? Due to a horrid merge mismatchmishmashmess I've staged them behind lots of other things, notably
thp/khugepaged improvements and CoW semantics
http://lkml.kernel.org/r/[email protected]
and mm: memcontrol: charge swapin pages on instantiation
http://lkml.kernel.org/r/[email protected]
and mm: balance LRU lists based on relative thrashing
http://lkml.kernel.org/r/[email protected]
Quoted 13 lines · Andrew Morton
Quoted 10 lines · On Wed, 27 May 2020 15:41:48 -0400 Johannes Weiner <[email protected]> wrote:
Quoted 9 lines · Shakeel Butt
From: Johannes Weiner <[email protected]>
Currently, THP are counted as single pages until they are split right before being swapped out. However, at that point the VM is already in the middle of reclaim, and adjusting the LRU balance then is useless.
Always account THP by the number of basepages, and remove the fixup from the splitting path.
Quoted 8 lines
Quoted 6 lines
Quoted 2 lines
Signed-off-by Johannes Weiner <[email protected]>Signed-off-by Shakeel Butt <[email protected]>This is now already in mm as part of the "mm: balance LRU lists based on relative thrashing" series that I sent out last week and where it was originally from.
Yup. I hope [1/3] and [2/3] weren't urgent?
No urgency.