The func is only used in huge_memory.c, defining it in other file with a
CONFIG_TRANSPARENT_HUGEPAGE macro restrict just looks weird.
Let's move it THP. And make it static as Hugh Dickin suggested.
Signed-off-by: Alex Shi <[email protected]>
Reviewed-by: Kirill A. Shutemov <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
include/linux/swap.h | 2 --
mm/huge_memory.c | 30 ++++++++++++++++++++++++++++++
mm/swap.c | 33 ---------------------------------
3 files changed, 30 insertions(+), 35 deletions(-)
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 661046994db4..43e6b3458f58 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -338,8 +338,6 @@ extern void lru_note_cost(struct lruvec *lruvec, bool file,
unsigned int nr_pages);
extern void lru_note_cost_page(struct page *);
extern void lru_cache_add(struct page *);
-extern void lru_add_page_tail(struct page *page, struct page *page_tail,
- struct lruvec *lruvec, struct list_head *head);
extern void activate_page(struct page *);
extern void mark_page_accessed(struct page *);
extern void lru_add_drain(void);
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 90733cefa528..bc905e7079bf 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2315,6 +2315,36 @@ static void remap_page(struct page *page)
}
}
+static void lru_add_page_tail(struct page *page, struct page *page_tail,
+ struct lruvec *lruvec, struct list_head *list)
+{
+ VM_BUG_ON_PAGE(!PageHead(page), page);
+ VM_BUG_ON_PAGE(PageCompound(page_tail), page);
+ VM_BUG_ON_PAGE(PageLRU(page_tail), page);
+ lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock);
+
+ if (!list)
+ SetPageLRU(page_tail);
+
+ if (likely(PageLRU(page)))
+ list_add_tail(&page_tail->lru, &page->lru);
+ else if (list) {
+ /* page reclaim is reclaiming a huge page */
+ get_page(page_tail);
+ list_add_tail(&page_tail->lru, list);
+ } else {
+ /*
+ * Head page has not yet been counted, as an hpage,
+ * so we must account for each subpage individually.
+ *
+ * Put page_tail on the list at the correct position
+ * so they all end up in order.
+ */
+ add_page_to_lru_list_tail(page_tail, lruvec,
+ page_lru(page_tail));
+ }
+}
+
static void __split_huge_page_tail(struct page *head, int tail,
struct lruvec *lruvec, struct list_head *list)
{
diff --git a/mm/swap.c b/mm/swap.c
index d16d65d9b4e0..c674fb441fe9 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -935,39 +935,6 @@ void __pagevec_release(struct pagevec *pvec)
}
EXPORT_SYMBOL(__pagevec_release);
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-/* used by __split_huge_page_refcount() */
-void lru_add_page_tail(struct page *page, struct page *page_tail,
- struct lruvec *lruvec, struct list_head *list)
-{
- VM_BUG_ON_PAGE(!PageHead(page), page);
- VM_BUG_ON_PAGE(PageCompound(page_tail), page);
- VM_BUG_ON_PAGE(PageLRU(page_tail), page);
- lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock);
-
- if (!list)
- SetPageLRU(page_tail);
-
- if (likely(PageLRU(page)))
- list_add_tail(&page_tail->lru, &page->lru);
- else if (list) {
- /* page reclaim is reclaiming a huge page */
- get_page(page_tail);
- list_add_tail(&page_tail->lru, list);
- } else {
- /*
- * Head page has not yet been counted, as an hpage,
- * so we must account for each subpage individually.
- *
- * Put page_tail on the list at the correct position
- * so they all end up in order.
- */
- add_page_to_lru_list_tail(page_tail, lruvec,
- page_lru(page_tail));
- }
-}
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
-
static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec,
void *arg)
{
--
1.8.3.1
lru_lock and page cache xa_lock have no reason with current sequence,
put them together isn't necessary. let's narrow the lru locking, but
left the local_irq_disable to block interrupt re-entry and statistic update.
Hugh Dickins point: split_huge_page_to_list() was already silly,to be
using the _irqsave variant: it's just been taking sleeping locks, so
would already be broken if entered with interrupts enabled.
so we can save passing flags argument down to __split_huge_page().
Signed-off-by: Alex Shi <[email protected]>
Signed-off-by: Wei Yang <[email protected]>
Reviewed-by: Kirill A. Shutemov <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
mm/huge_memory.c | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index dfe7378ab4be..070480e66bf4 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2398,7 +2398,7 @@ static void __split_huge_page_tail(struct page *head, int tail,
}
static void __split_huge_page(struct page *page, struct list_head *list,
- pgoff_t end, unsigned long flags)
+ pgoff_t end)
{
struct page *head = compound_head(page);
pg_data_t *pgdat = page_pgdat(head);
@@ -2407,8 +2407,6 @@ static void __split_huge_page(struct page *page, struct list_head *list,
unsigned long offset = 0;
int i;
- lruvec = mem_cgroup_page_lruvec(head, pgdat);
-
/* complete memcg works before add pages to LRU */
mem_cgroup_split_huge_fixup(head);
@@ -2420,6 +2418,11 @@ static void __split_huge_page(struct page *page, struct list_head *list,
xa_lock(&swap_cache->i_pages);
}
+ /* prevent PageLRU to go away from under us, and freeze lru stats */
+ spin_lock(&pgdat->lru_lock);
+
+ lruvec = mem_cgroup_page_lruvec(head, pgdat);
+
for (i = HPAGE_PMD_NR - 1; i >= 1; i--) {
__split_huge_page_tail(head, i, lruvec, list);
/* Some pages can be beyond i_size: drop them from page cache */
@@ -2439,6 +2442,8 @@ static void __split_huge_page(struct page *page, struct list_head *list,
}
ClearPageCompound(head);
+ spin_unlock(&pgdat->lru_lock);
+ /* Caller disabled irqs, so they are still disabled here */
split_page_owner(head, HPAGE_PMD_ORDER);
@@ -2456,8 +2461,7 @@ static void __split_huge_page(struct page *page, struct list_head *list,
page_ref_add(head, 2);
xa_unlock(&head->mapping->i_pages);
}
-
- spin_unlock_irqrestore(&pgdat->lru_lock, flags);
+ local_irq_enable();
remap_page(head);
@@ -2596,12 +2600,10 @@ bool can_split_huge_page(struct page *page, int *pextra_pins)
int split_huge_page_to_list(struct page *page, struct list_head *list)
{
struct page *head = compound_head(page);
- struct pglist_data *pgdata = NODE_DATA(page_to_nid(head));
struct deferred_split *ds_queue = get_deferred_split_queue(head);
struct anon_vma *anon_vma = NULL;
struct address_space *mapping = NULL;
int count, mapcount, extra_pins, ret;
- unsigned long flags;
pgoff_t end;
VM_BUG_ON_PAGE(is_huge_zero_page(head), head);
@@ -2662,9 +2664,8 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
unmap_page(head);
VM_BUG_ON_PAGE(compound_mapcount(head), head);
- /* prevent PageLRU to go away from under us, and freeze lru stats */
- spin_lock_irqsave(&pgdata->lru_lock, flags);
-
+ /* block interrupt reentry in xa_lock and spinlock */
+ local_irq_disable();
if (mapping) {
XA_STATE(xas, &mapping->i_pages, page_index(head));
@@ -2694,7 +2695,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
__dec_node_page_state(head, NR_FILE_THPS);
}
- __split_huge_page(page, list, end, flags);
+ __split_huge_page(page, list, end);
if (PageSwapCache(head)) {
swp_entry_t entry = { .val = page_private(head) };
@@ -2713,7 +2714,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
spin_unlock(&ds_queue->split_queue_lock);
fail: if (mapping)
xa_unlock(&mapping->i_pages);
- spin_unlock_irqrestore(&pgdata->lru_lock, flags);
+ local_irq_enable();
remap_page(head);
ret = -EBUSY;
}
--
1.8.3.1
Hi Andrew,
This patchset is just cleanup and get reviewed by Kirill, is it cath up 5.9?
Thanks
Alex
?? 2020/8/1 ????12:09, Alex Shi д??:
> The func is only used in huge_memory.c, defining it in other file with a
> CONFIG_TRANSPARENT_HUGEPAGE macro restrict just looks weird.
>
> Let's move it THP. And make it static as Hugh Dickin suggested.
>
> Signed-off-by: Alex Shi <[email protected]>
> Reviewed-by: Kirill A. Shutemov <[email protected]>
> Cc: Andrew Morton <[email protected]>
> Cc: Johannes Weiner <[email protected]>
> Cc: Matthew Wilcox <[email protected]>
> Cc: Hugh Dickins <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> ---
> include/linux/swap.h | 2 --
> mm/huge_memory.c | 30 ++++++++++++++++++++++++++++++
> mm/swap.c | 33 ---------------------------------
> 3 files changed, 30 insertions(+), 35 deletions(-)
>
> diff --git a/include/linux/swap.h b/include/linux/swap.h
> index 661046994db4..43e6b3458f58 100644
> --- a/include/linux/swap.h
> +++ b/include/linux/swap.h
> @@ -338,8 +338,6 @@ extern void lru_note_cost(struct lruvec *lruvec, bool file,
> unsigned int nr_pages);
> extern void lru_note_cost_page(struct page *);
> extern void lru_cache_add(struct page *);
> -extern void lru_add_page_tail(struct page *page, struct page *page_tail,
> - struct lruvec *lruvec, struct list_head *head);
> extern void activate_page(struct page *);
> extern void mark_page_accessed(struct page *);
> extern void lru_add_drain(void);
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 90733cefa528..bc905e7079bf 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -2315,6 +2315,36 @@ static void remap_page(struct page *page)
> }
> }
>
> +static void lru_add_page_tail(struct page *page, struct page *page_tail,
> + struct lruvec *lruvec, struct list_head *list)
> +{
> + VM_BUG_ON_PAGE(!PageHead(page), page);
> + VM_BUG_ON_PAGE(PageCompound(page_tail), page);
> + VM_BUG_ON_PAGE(PageLRU(page_tail), page);
> + lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock);
> +
> + if (!list)
> + SetPageLRU(page_tail);
> +
> + if (likely(PageLRU(page)))
> + list_add_tail(&page_tail->lru, &page->lru);
> + else if (list) {
> + /* page reclaim is reclaiming a huge page */
> + get_page(page_tail);
> + list_add_tail(&page_tail->lru, list);
> + } else {
> + /*
> + * Head page has not yet been counted, as an hpage,
> + * so we must account for each subpage individually.
> + *
> + * Put page_tail on the list at the correct position
> + * so they all end up in order.
> + */
> + add_page_to_lru_list_tail(page_tail, lruvec,
> + page_lru(page_tail));
> + }
> +}
> +
> static void __split_huge_page_tail(struct page *head, int tail,
> struct lruvec *lruvec, struct list_head *list)
> {
> diff --git a/mm/swap.c b/mm/swap.c
> index d16d65d9b4e0..c674fb441fe9 100644
> --- a/mm/swap.c
> +++ b/mm/swap.c
> @@ -935,39 +935,6 @@ void __pagevec_release(struct pagevec *pvec)
> }
> EXPORT_SYMBOL(__pagevec_release);
>
> -#ifdef CONFIG_TRANSPARENT_HUGEPAGE
> -/* used by __split_huge_page_refcount() */
> -void lru_add_page_tail(struct page *page, struct page *page_tail,
> - struct lruvec *lruvec, struct list_head *list)
> -{
> - VM_BUG_ON_PAGE(!PageHead(page), page);
> - VM_BUG_ON_PAGE(PageCompound(page_tail), page);
> - VM_BUG_ON_PAGE(PageLRU(page_tail), page);
> - lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock);
> -
> - if (!list)
> - SetPageLRU(page_tail);
> -
> - if (likely(PageLRU(page)))
> - list_add_tail(&page_tail->lru, &page->lru);
> - else if (list) {
> - /* page reclaim is reclaiming a huge page */
> - get_page(page_tail);
> - list_add_tail(&page_tail->lru, list);
> - } else {
> - /*
> - * Head page has not yet been counted, as an hpage,
> - * so we must account for each subpage individually.
> - *
> - * Put page_tail on the list at the correct position
> - * so they all end up in order.
> - */
> - add_page_to_lru_list_tail(page_tail, lruvec,
> - page_lru(page_tail));
> - }
> -}
> -#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
> -
> static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec,
> void *arg)
> {
>
You're playing games with separating interrupt disabling from spinlocks.
Have you got any feedback from -rt people on this?
On Sat, Aug 01, 2020 at 12:09:17PM +0800, Alex Shi wrote:
> lru_lock and page cache xa_lock have no reason with current sequence,
> put them together isn't necessary. let's narrow the lru locking, but
> left the local_irq_disable to block interrupt re-entry and statistic update.
>
> Hugh Dickins point: split_huge_page_to_list() was already silly,to be
> using the _irqsave variant: it's just been taking sleeping locks, so
> would already be broken if entered with interrupts enabled.
> so we can save passing flags argument down to __split_huge_page().
>
> Signed-off-by: Alex Shi <[email protected]>
> Signed-off-by: Wei Yang <[email protected]>
> Reviewed-by: Kirill A. Shutemov <[email protected]>
> Cc: Hugh Dickins <[email protected]>
> Cc: Kirill A. Shutemov <[email protected]>
> Cc: Andrea Arcangeli <[email protected]>
> Cc: Johannes Weiner <[email protected]>
> Cc: Matthew Wilcox <[email protected]>
> Cc: Andrew Morton <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> ---
> mm/huge_memory.c | 25 +++++++++++++------------
> 1 file changed, 13 insertions(+), 12 deletions(-)
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index dfe7378ab4be..070480e66bf4 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -2398,7 +2398,7 @@ static void __split_huge_page_tail(struct page *head, int tail,
> }
>
> static void __split_huge_page(struct page *page, struct list_head *list,
> - pgoff_t end, unsigned long flags)
> + pgoff_t end)
> {
> struct page *head = compound_head(page);
> pg_data_t *pgdat = page_pgdat(head);
> @@ -2407,8 +2407,6 @@ static void __split_huge_page(struct page *page, struct list_head *list,
> unsigned long offset = 0;
> int i;
>
> - lruvec = mem_cgroup_page_lruvec(head, pgdat);
> -
> /* complete memcg works before add pages to LRU */
> mem_cgroup_split_huge_fixup(head);
>
> @@ -2420,6 +2418,11 @@ static void __split_huge_page(struct page *page, struct list_head *list,
> xa_lock(&swap_cache->i_pages);
> }
>
> + /* prevent PageLRU to go away from under us, and freeze lru stats */
> + spin_lock(&pgdat->lru_lock);
> +
> + lruvec = mem_cgroup_page_lruvec(head, pgdat);
> +
> for (i = HPAGE_PMD_NR - 1; i >= 1; i--) {
> __split_huge_page_tail(head, i, lruvec, list);
> /* Some pages can be beyond i_size: drop them from page cache */
> @@ -2439,6 +2442,8 @@ static void __split_huge_page(struct page *page, struct list_head *list,
> }
>
> ClearPageCompound(head);
> + spin_unlock(&pgdat->lru_lock);
> + /* Caller disabled irqs, so they are still disabled here */
>
> split_page_owner(head, HPAGE_PMD_ORDER);
>
> @@ -2456,8 +2461,7 @@ static void __split_huge_page(struct page *page, struct list_head *list,
> page_ref_add(head, 2);
> xa_unlock(&head->mapping->i_pages);
> }
> -
> - spin_unlock_irqrestore(&pgdat->lru_lock, flags);
> + local_irq_enable();
>
> remap_page(head);
>
> @@ -2596,12 +2600,10 @@ bool can_split_huge_page(struct page *page, int *pextra_pins)
> int split_huge_page_to_list(struct page *page, struct list_head *list)
> {
> struct page *head = compound_head(page);
> - struct pglist_data *pgdata = NODE_DATA(page_to_nid(head));
> struct deferred_split *ds_queue = get_deferred_split_queue(head);
> struct anon_vma *anon_vma = NULL;
> struct address_space *mapping = NULL;
> int count, mapcount, extra_pins, ret;
> - unsigned long flags;
> pgoff_t end;
>
> VM_BUG_ON_PAGE(is_huge_zero_page(head), head);
> @@ -2662,9 +2664,8 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
> unmap_page(head);
> VM_BUG_ON_PAGE(compound_mapcount(head), head);
>
> - /* prevent PageLRU to go away from under us, and freeze lru stats */
> - spin_lock_irqsave(&pgdata->lru_lock, flags);
> -
> + /* block interrupt reentry in xa_lock and spinlock */
> + local_irq_disable();
> if (mapping) {
> XA_STATE(xas, &mapping->i_pages, page_index(head));
>
> @@ -2694,7 +2695,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
> __dec_node_page_state(head, NR_FILE_THPS);
> }
>
> - __split_huge_page(page, list, end, flags);
> + __split_huge_page(page, list, end);
> if (PageSwapCache(head)) {
> swp_entry_t entry = { .val = page_private(head) };
>
> @@ -2713,7 +2714,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
> spin_unlock(&ds_queue->split_queue_lock);
> fail: if (mapping)
> xa_unlock(&mapping->i_pages);
> - spin_unlock_irqrestore(&pgdata->lru_lock, flags);
> + local_irq_enable();
> remap_page(head);
> ret = -EBUSY;
> }
> --
> 1.8.3.1
>
?? 2020/8/2 ????7:09, Matthew Wilcox д??:
> You're playing games with separating interrupt disabling from spinlocks.
> Have you got any feedback from -rt people on this?
Is there other suggestions to remove local_irq_disable?
Just check again on kernel/mm directory on linux-next. there are still
much local_irq_disable there.
Guess we need a final solution instead of block new one.
Thanks
Alex