[PATCH v4 09/13] mm/khugepaged: rename prefix of shared collapse functions

["Zach O'Keefe" <zokeefe@google.com>]

The following functions/tracepoints are shared between khugepaged and
madvise collapse contexts.  Replace the "khugepaged_" prefixe with
generic "hpage_collapse_" prefix in such cases:

huge_memory:mm_khugepaged_scan_pmd -> huge_memory:mm_hpage_collapse_scan_pmd
khugepaged_test_exit() -> hpage_collapse_test_exit()
khugepaged_scan_abort() -> hpage_collapse_scan_abort()
khugepaged_scan_pmd() -> hpage_collapse_scan_pmd()
khugepaged_find_target_node() -> hpage_collapse_find_target_node()

Signed-off-by: Zach O'Keefe <zokeefe@google.com>
---
 include/trace/events/huge_memory.h |  2 +-
 mm/khugepaged.c                    | 72 ++++++++++++++++--------------
 2 files changed, 39 insertions(+), 35 deletions(-)

diff --git a/include/trace/events/huge_memory.h b/include/trace/events/huge_memory.h
index 55392bf30a03..fb6c73632ff3 100644
--- a/include/trace/events/huge_memory.h
+++ b/include/trace/events/huge_memory.h
@@ -48,7 +48,7 @@ SCAN_STATUS
 #define EM(a, b)	{a, b},
 #define EMe(a, b)	{a, b}
 
-TRACE_EVENT(mm_khugepaged_scan_pmd,
+TRACE_EVENT(mm_hpage_collapse_scan_pmd,
 
 	TP_PROTO(struct mm_struct *mm, struct page *page, bool writable,
 		 int referenced, int none_or_zero, int status, int unmapped),
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 3ba2c570da5e..9f1b7e9e78c2 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -96,7 +96,7 @@ struct collapse_control {
 	/* Num pages scanned per node */
 	int node_load[MAX_NUMNODES];
 
-	/* Last target selected in khugepaged_find_target_node() */
+	/* Last target selected in hpage_collapse_find_target_node() */
 	int last_target_node;
 
 	struct page *hpage;
@@ -453,7 +453,7 @@ static void insert_to_mm_slots_hash(struct mm_struct *mm,
 	hash_add(mm_slots_hash, &mm_slot->hash, (long)mm);
 }
 
-static inline int khugepaged_test_exit(struct mm_struct *mm)
+static inline int hpage_collapse_test_exit(struct mm_struct *mm)
 {
 	return atomic_read(&mm->mm_users) == 0;
 }
@@ -502,7 +502,7 @@ int __khugepaged_enter(struct mm_struct *mm)
 		return -ENOMEM;
 
 	/* __khugepaged_exit() must not run from under us */
-	VM_BUG_ON_MM(khugepaged_test_exit(mm), mm);
+	VM_BUG_ON_MM(hpage_collapse_test_exit(mm), mm);
 	if (unlikely(test_and_set_bit(MMF_VM_HUGEPAGE, &mm->flags))) {
 		free_mm_slot(mm_slot);
 		return 0;
@@ -566,11 +566,10 @@ void __khugepaged_exit(struct mm_struct *mm)
 	} else if (mm_slot) {
 		/*
 		 * This is required to serialize against
-		 * khugepaged_test_exit() (which is guaranteed to run
-		 * under mmap sem read mode). Stop here (after we
-		 * return all pagetables will be destroyed) until
-		 * khugepaged has finished working on the pagetables
-		 * under the mmap_lock.
+		 * hpage_collapse_test_exit() (which is guaranteed to run
+		 * under mmap sem read mode). Stop here (after we return all
+		 * pagetables will be destroyed) until khugepaged has finished
+		 * working on the pagetables under the mmap_lock.
 		 */
 		mmap_write_lock(mm);
 		mmap_write_unlock(mm);
@@ -807,7 +806,7 @@ static void khugepaged_alloc_sleep(void)
 	remove_wait_queue(&khugepaged_wait, &wait);
 }
 
-static bool khugepaged_scan_abort(int nid, struct collapse_control *cc)
+static bool hpage_collapse_scan_abort(int nid, struct collapse_control *cc)
 {
 	int i;
 
@@ -854,7 +853,7 @@ static bool alloc_hpage(gfp_t gfp, int node, struct collapse_control *cc)
 }
 
 #ifdef CONFIG_NUMA
-static int khugepaged_find_target_node(struct collapse_control *cc)
+static int hpage_collapse_find_target_node(struct collapse_control *cc)
 {
 	int nid, target_node = 0, max_value = 0;
 
@@ -901,7 +900,7 @@ static bool khugepaged_alloc_page(gfp_t gfp, int node,
 	return alloc_hpage(gfp, node, cc);
 }
 #else
-static int khugepaged_find_target_node(struct collapse_control *cc)
+static int hpage_collapse_find_target_node(struct collapse_control *cc)
 {
 	return 0;
 }
@@ -981,7 +980,7 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address,
 	struct vm_area_struct *vma;
 	unsigned long hstart, hend;
 
-	if (unlikely(khugepaged_test_exit(mm)))
+	if (unlikely(hpage_collapse_test_exit(mm)))
 		return SCAN_ANY_PROCESS;
 
 	*vmap = vma = find_vma(mm, address);
@@ -1025,7 +1024,7 @@ static int find_pmd_or_thp_or_none(struct mm_struct *mm,
 
 /*
  * Bring missing pages in from swap, to complete THP collapse.
- * Only done if khugepaged_scan_pmd believes it is worthwhile.
+ * Only done if hpage_collapse_scan_pmd believes it is worthwhile.
  *
  * Called and returns without pte mapped or spinlocks held,
  * but with mmap_lock held to protect against vma changes.
@@ -1092,7 +1091,7 @@ static int alloc_charge_hpage(struct mm_struct *mm, struct collapse_control *cc)
 	const struct cpumask *cpumask;
 #endif
 	gfp_t gfp = alloc_hugepage_khugepaged_gfpmask() | __GFP_THISNODE;
-	int node = khugepaged_find_target_node(cc);
+	int node = hpage_collapse_find_target_node(cc);
 
 #ifdef CONFIG_NUMA
 	/* sched to specified node before huge page memory copy */
@@ -1262,9 +1261,10 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address,
 	return result;
 }
 
-static int khugepaged_scan_pmd(struct mm_struct *mm, struct vm_area_struct *vma,
-			       unsigned long address, bool *mmap_locked,
-			       struct collapse_control *cc)
+static int hpage_collapse_scan_pmd(struct mm_struct *mm,
+				   struct vm_area_struct *vma,
+				   unsigned long address, bool *mmap_locked,
+				   struct collapse_control *cc)
 {
 	pmd_t *pmd;
 	pte_t *pte, *_pte;
@@ -1358,7 +1358,7 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, struct vm_area_struct *vma,
 		 * hit record.
 		 */
 		node = page_to_nid(page);
-		if (khugepaged_scan_abort(node, cc)) {
+		if (hpage_collapse_scan_abort(node, cc)) {
 			result = SCAN_SCAN_ABORT;
 			goto out_unmap;
 		}
@@ -1423,8 +1423,8 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, struct vm_area_struct *vma,
 					    unmapped, cc);
 	}
 out:
-	trace_mm_khugepaged_scan_pmd(mm, page, writable, referenced,
-				     none_or_zero, result, unmapped);
+	trace_mm_hpage_collapse_scan_pmd(mm, page, writable, referenced,
+					 none_or_zero, result, unmapped);
 	return result;
 }
 
@@ -1434,7 +1434,7 @@ static void collect_mm_slot(struct mm_slot *mm_slot)
 
 	lockdep_assert_held(&khugepaged_mm_lock);
 
-	if (khugepaged_test_exit(mm)) {
+	if (hpage_collapse_test_exit(mm)) {
 		/* free mm_slot */
 		hash_del(&mm_slot->hash);
 		list_del(&mm_slot->mm_node);
@@ -1605,7 +1605,7 @@ static void khugepaged_collapse_pte_mapped_thps(struct mm_slot *mm_slot)
 	if (!mmap_write_trylock(mm))
 		return;
 
-	if (unlikely(khugepaged_test_exit(mm)))
+	if (unlikely(hpage_collapse_test_exit(mm)))
 		goto out;
 
 	for (i = 0; i < mm_slot->nr_pte_mapped_thp; i++)
@@ -1668,7 +1668,8 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff)
 			 * it'll always mapped in small page size for uffd-wp
 			 * registered ranges.
 			 */
-			if (!khugepaged_test_exit(mm) && !userfaultfd_wp(vma))
+			if (!hpage_collapse_test_exit(mm) &&
+			    !userfaultfd_wp(vma))
 				collapse_and_free_pmd(mm, vma, addr, pmd);
 			mmap_write_unlock(mm);
 		} else {
@@ -2094,7 +2095,7 @@ static int khugepaged_scan_file(struct mm_struct *mm,
 		}
 
 		node = page_to_nid(page);
-		if (khugepaged_scan_abort(node, cc)) {
+		if (hpage_collapse_scan_abort(node, cc)) {
 			result = SCAN_SCAN_ABORT;
 			break;
 		}
@@ -2183,7 +2184,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
 	vma = NULL;
 	if (unlikely(!mmap_read_trylock(mm)))
 		goto breakouterloop_mmap_lock;
-	if (likely(!khugepaged_test_exit(mm)))
+	if (likely(!hpage_collapse_test_exit(mm)))
 		vma = find_vma(mm, khugepaged_scan.address);
 
 	progress++;
@@ -2191,7 +2192,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
 		unsigned long hstart, hend;
 
 		cond_resched();
-		if (unlikely(khugepaged_test_exit(mm))) {
+		if (unlikely(hpage_collapse_test_exit(mm))) {
 			progress++;
 			break;
 		}
@@ -2217,7 +2218,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
 			bool mmap_locked;
 
 			cond_resched();
-			if (unlikely(khugepaged_test_exit(mm)))
+			if (unlikely(hpage_collapse_test_exit(mm)))
 				goto breakouterloop;
 
 			VM_BUG_ON(khugepaged_scan.address < hstart ||
@@ -2234,9 +2235,10 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
 							      cc);
 				fput(file);
 			} else {
-				result = khugepaged_scan_pmd(mm, vma,
-							     khugepaged_scan.address,
-							     &mmap_locked, cc);
+				result = hpage_collapse_scan_pmd(mm, vma,
+								 khugepaged_scan.address,
+								 &mmap_locked,
+								 cc);
 			}
 			if (result == SCAN_SUCCEED)
 				++khugepaged_pages_collapsed;
@@ -2260,7 +2262,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
 	 * Release the current mm_slot if this mm is about to die, or
 	 * if we scanned all vmas of this mm.
 	 */
-	if (khugepaged_test_exit(mm) || !vma) {
+	if (hpage_collapse_test_exit(mm) || !vma) {
 		/*
 		 * Make sure that if mm_users is reaching zero while
 		 * khugepaged runs here, khugepaged_exit will find
@@ -2500,7 +2502,8 @@ static int madvise_collapse_errno(enum scan_result r)
 static int madvise_alloc_charge_hpage(struct mm_struct *mm,
 				      struct collapse_control *cc)
 {
-	if (!alloc_hpage(GFP_TRANSHUGE, khugepaged_find_target_node(cc), cc))
+	if (!alloc_hpage(GFP_TRANSHUGE, hpage_collapse_find_target_node(cc),
+			 cc))
 		return SCAN_ALLOC_HUGE_PAGE_FAIL;
 	if (unlikely(mem_cgroup_charge(page_folio(cc->hpage), mm,
 				       GFP_TRANSHUGE)))
@@ -2547,13 +2550,14 @@ int madvise_collapse(struct vm_area_struct *vma, struct vm_area_struct **prev,
 		cond_resched();
 		result = SCAN_FAIL;
 
-		if (unlikely(khugepaged_test_exit(mm))) {
+		if (unlikely(hpage_collapse_test_exit(mm))) {
 			result = SCAN_ANY_PROCESS;
 			break;
 		}
 
 		memset(cc.node_load, 0, sizeof(cc.node_load));
-		result = khugepaged_scan_pmd(mm, vma, addr, &mmap_locked, &cc);
+		result = hpage_collapse_scan_pmd(mm, vma, addr, &mmap_locked,
+						 &cc);
 		if (!mmap_locked)
 			*prev = NULL;  /* tell madvise we dropped mmap_lock */
 
-- 
2.36.0.464.gb9c8b46e94-goog