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Message-Id: <20220204195852.1751729-46-willy@infradead.org>
Date: Fri, 4 Feb 2022 19:58:22 +0000
From: "Matthew Wilcox (Oracle)" <willy@...radead.org>
To: linux-mm@...ck.org
Cc: "Matthew Wilcox (Oracle)" <willy@...radead.org>,
linux-kernel@...r.kernel.org
Subject: [PATCH 45/75] mm/rmap: Turn page_referenced() into folio_referenced()
Both its callers pass a page which was previously on an LRU list,
so were passing a folio by definition. Use the type system to enforce
that and remove a few calls to compound_head().
Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
---
include/linux/rmap.h | 4 ++--
mm/mlock.c | 4 ++--
mm/page_idle.c | 2 +-
mm/rmap.c | 46 ++++++++++++++++++++++----------------------
mm/vmscan.c | 20 +++++++++++--------
5 files changed, 40 insertions(+), 36 deletions(-)
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 29ea97c5e96a..00b772cdaaaa 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -189,7 +189,7 @@ static inline void page_dup_rmap(struct page *page, bool compound)
/*
* Called from mm/vmscan.c to handle paging out
*/
-int page_referenced(struct page *, int is_locked,
+int folio_referenced(struct folio *, int is_locked,
struct mem_cgroup *memcg, unsigned long *vm_flags);
void try_to_migrate(struct page *page, enum ttu_flags flags);
@@ -302,7 +302,7 @@ void rmap_walk_locked(struct page *page, struct rmap_walk_control *rwc);
#define anon_vma_prepare(vma) (0)
#define anon_vma_link(vma) do {} while (0)
-static inline int page_referenced(struct page *page, int is_locked,
+static inline int folio_referenced(struct folio *folio, int is_locked,
struct mem_cgroup *memcg,
unsigned long *vm_flags)
{
diff --git a/mm/mlock.c b/mm/mlock.c
index 8f584eddd305..24d0809cacba 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -134,7 +134,7 @@ static void __munlock_isolated_page(struct page *page)
* Performs accounting when page isolation fails in munlock. There is nothing
* else to do because it means some other task has already removed the page
* from the LRU. putback_lru_page() will take care of removing the page from
- * the unevictable list, if necessary. vmscan [page_referenced()] will move
+ * the unevictable list, if necessary. vmscan [folio_referenced()] will move
* the page back to the unevictable list if some other vma has it mlocked.
*/
static void __munlock_isolation_failed(struct page *page)
@@ -163,7 +163,7 @@ static void __munlock_isolation_failed(struct page *page)
* task has removed the page from the LRU, we won't be able to do that.
* So we clear the PageMlocked as we might not get another chance. If we
* can't isolate the page, we leave it for putback_lru_page() and vmscan
- * [page_referenced()/try_to_unmap()] to deal with.
+ * [folio_referenced()/try_to_unmap()] to deal with.
*/
unsigned int munlock_vma_page(struct page *page)
{
diff --git a/mm/page_idle.c b/mm/page_idle.c
index 544814bd9e37..35e53db430df 100644
--- a/mm/page_idle.c
+++ b/mm/page_idle.c
@@ -81,7 +81,7 @@ static bool page_idle_clear_pte_refs_one(struct page *page,
/*
* We cleared the referenced bit in a mapping to this page. To
* avoid interference with page reclaim, mark it young so that
- * page_referenced() will return > 0.
+ * folio_referenced() will return > 0.
*/
folio_set_young(folio);
}
diff --git a/mm/rmap.c b/mm/rmap.c
index 18ae6bd79efd..1cedcfd6105c 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -801,6 +801,7 @@ struct page_referenced_arg {
static bool page_referenced_one(struct page *page, struct vm_area_struct *vma,
unsigned long address, void *arg)
{
+ struct folio *folio = page_folio(page);
struct page_referenced_arg *pra = arg;
struct page_vma_mapped_walk pvmw = {
.vma = vma,
@@ -824,10 +825,10 @@ static bool page_referenced_one(struct page *page, struct vm_area_struct *vma,
/*
* Don't treat a reference through
* a sequentially read mapping as such.
- * If the page has been used in another mapping,
+ * If the folio has been used in another mapping,
* we will catch it; if this other mapping is
* already gone, the unmap path will have set
- * PG_referenced or activated the page.
+ * the referenced flag or activated the folio.
*/
if (likely(!(vma->vm_flags & VM_SEQ_READ)))
referenced++;
@@ -837,7 +838,7 @@ static bool page_referenced_one(struct page *page, struct vm_area_struct *vma,
pvmw.pmd))
referenced++;
} else {
- /* unexpected pmd-mapped page? */
+ /* unexpected pmd-mapped folio? */
WARN_ON_ONCE(1);
}
@@ -845,8 +846,8 @@ static bool page_referenced_one(struct page *page, struct vm_area_struct *vma,
}
if (referenced)
- clear_page_idle(page);
- if (test_and_clear_page_young(page))
+ folio_clear_idle(folio);
+ if (folio_test_clear_young(folio))
referenced++;
if (referenced) {
@@ -872,23 +873,22 @@ static bool invalid_page_referenced_vma(struct vm_area_struct *vma, void *arg)
}
/**
- * page_referenced - test if the page was referenced
- * @page: the page to test
- * @is_locked: caller holds lock on the page
+ * folio_referenced() - Test if the folio was referenced.
+ * @folio: The folio to test.
+ * @is_locked: Caller holds lock on the folio.
* @memcg: target memory cgroup
- * @vm_flags: collect encountered vma->vm_flags who actually referenced the page
+ * @vm_flags: A combination of all the vma->vm_flags which referenced the folio.
+ *
+ * Quick test_and_clear_referenced for all mappings of a folio,
*
- * Quick test_and_clear_referenced for all mappings to a page,
- * returns the number of ptes which referenced the page.
+ * Return: The number of mappings which referenced the folio.
*/
-int page_referenced(struct page *page,
- int is_locked,
- struct mem_cgroup *memcg,
- unsigned long *vm_flags)
+int folio_referenced(struct folio *folio, int is_locked,
+ struct mem_cgroup *memcg, unsigned long *vm_flags)
{
int we_locked = 0;
struct page_referenced_arg pra = {
- .mapcount = total_mapcount(page),
+ .mapcount = folio_mapcount(folio),
.memcg = memcg,
};
struct rmap_walk_control rwc = {
@@ -901,11 +901,11 @@ int page_referenced(struct page *page,
if (!pra.mapcount)
return 0;
- if (!page_rmapping(page))
+ if (!folio_raw_mapping(folio))
return 0;
- if (!is_locked && (!PageAnon(page) || PageKsm(page))) {
- we_locked = trylock_page(page);
+ if (!is_locked && (!folio_test_anon(folio) || folio_test_ksm(folio))) {
+ we_locked = folio_trylock(folio);
if (!we_locked)
return 1;
}
@@ -919,11 +919,11 @@ int page_referenced(struct page *page,
rwc.invalid_vma = invalid_page_referenced_vma;
}
- rmap_walk(page, &rwc);
+ rmap_walk(&folio->page, &rwc);
*vm_flags = pra.vm_flags;
if (we_locked)
- unlock_page(page);
+ folio_unlock(folio);
return pra.referenced;
}
@@ -1058,8 +1058,8 @@ void page_move_anon_rmap(struct page *page, struct vm_area_struct *vma)
anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
/*
* Ensure that anon_vma and the PAGE_MAPPING_ANON bit are written
- * simultaneously, so a concurrent reader (eg page_referenced()'s
- * PageAnon()) will not see one without the other.
+ * simultaneously, so a concurrent reader (eg folio_referenced()'s
+ * folio_test_anon()) will not see one without the other.
*/
WRITE_ONCE(page->mapping, (struct address_space *) anon_vma);
}
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 0d23ade9f6e2..1e751ba3b4a8 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1379,11 +1379,12 @@ enum page_references {
static enum page_references page_check_references(struct page *page,
struct scan_control *sc)
{
+ struct folio *folio = page_folio(page);
int referenced_ptes, referenced_page;
unsigned long vm_flags;
- referenced_ptes = page_referenced(page, 1, sc->target_mem_cgroup,
- &vm_flags);
+ referenced_ptes = folio_referenced(folio, 1, sc->target_mem_cgroup,
+ &vm_flags);
referenced_page = TestClearPageReferenced(page);
/*
@@ -2483,7 +2484,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
*
* If the pages are mostly unmapped, the processing is fast and it is
* appropriate to hold lru_lock across the whole operation. But if
- * the pages are mapped, the processing is slow (page_referenced()), so
+ * the pages are mapped, the processing is slow (folio_referenced()), so
* we should drop lru_lock around each page. It's impossible to balance
* this, so instead we remove the pages from the LRU while processing them.
* It is safe to rely on PG_active against the non-LRU pages in here because
@@ -2503,7 +2504,6 @@ static void shrink_active_list(unsigned long nr_to_scan,
LIST_HEAD(l_hold); /* The pages which were snipped off */
LIST_HEAD(l_active);
LIST_HEAD(l_inactive);
- struct page *page;
unsigned nr_deactivate, nr_activate;
unsigned nr_rotated = 0;
int file = is_file_lru(lru);
@@ -2525,9 +2525,13 @@ static void shrink_active_list(unsigned long nr_to_scan,
spin_unlock_irq(&lruvec->lru_lock);
while (!list_empty(&l_hold)) {
+ struct folio *folio;
+ struct page *page;
+
cond_resched();
- page = lru_to_page(&l_hold);
- list_del(&page->lru);
+ folio = lru_to_folio(&l_hold);
+ list_del(&folio->lru);
+ page = &folio->page;
if (unlikely(!page_evictable(page))) {
putback_lru_page(page);
@@ -2542,8 +2546,8 @@ static void shrink_active_list(unsigned long nr_to_scan,
}
}
- if (page_referenced(page, 0, sc->target_mem_cgroup,
- &vm_flags)) {
+ if (folio_referenced(folio, 0, sc->target_mem_cgroup,
+ &vm_flags)) {
/*
* Identify referenced, file-backed active pages and
* give them one more trip around the active list. So
--
2.34.1
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