ANDROID: vendor_hook: Add hook to not be stuck ro rmap lock in kswapd or direct_reclaim

Add hooks to support trylock in rmaplock when reclaiming in kswapd or
direct_reclaim, in order to avoid wait lock for a long time.

- android_vh_handle_failed_page_trylock
- android_vh_page_trylock_set
- android_vh_page_trylock_clear
- android_vh_page_trylock_get_result
- android_vh_do_page_trylock

Bug: 240003372

Signed-off-by: Peifeng Li <lipeifeng@oppo.com>
Change-Id: I0f605b35ae41f15b3ca7bc72cd5f003175c318a5

drivers/android/vendor_hooks.c

@@ -251,6 +251,11 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_freq_qos_update_request);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_freq_qos_remove_request);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_set_balance_anon_file_reclaim);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_show_max_freq);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_handle_failed_page_trylock);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_page_trylock_set);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_page_trylock_clear);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_page_trylock_get_result);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_do_page_trylock);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_page_referenced_check_bypass);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_drain_all_pages_bypass);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_cma_drain_all_pages_bypass);

include/trace/hooks/mm.h

@@ -21,6 +21,7 @@
 #include <linux/mm.h>
 #include <linux/oom.h>
 #include <trace/hooks/vendor_hooks.h>
+#include <linux/rwsem.h>
 
 /* struct slabinfo */
 #include <../mm/slab.h>
@@ -91,6 +92,10 @@ DECLARE_HOOK(android_vh_mem_cgroup_css_offline,
 DECLARE_HOOK(android_vh_vmpressure,
 	TP_PROTO(struct mem_cgroup *memcg, bool *bypass),
 	TP_ARGS(memcg, bypass));
+DECLARE_HOOK(android_vh_do_page_trylock,
+	TP_PROTO(struct page *page, struct rw_semaphore *sem,
+		bool *got_lock, bool *success),
+	TP_ARGS(page, sem, got_lock, success));
 DECLARE_HOOK(android_vh_update_page_mapcount,
 	TP_PROTO(struct page *page, bool inc_size, bool compound,
 			bool *first_mapping, bool *success),

include/trace/hooks/vmscan.h

@@ -18,7 +18,18 @@ DECLARE_HOOK(android_vh_kswapd_per_node,
 DECLARE_HOOK(android_vh_page_referenced_check_bypass,
 	TP_PROTO(struct page *page, unsigned long nr_to_scan, int lru, bool *bypass),
 	TP_ARGS(page, nr_to_scan, lru, bypass));
-
+DECLARE_HOOK(android_vh_page_trylock_get_result,
+	TP_PROTO(struct page *page, bool *trylock_fail),
+	TP_ARGS(page, trylock_fail));
+DECLARE_HOOK(android_vh_handle_failed_page_trylock,
+	TP_PROTO(struct list_head *page_list),
+	TP_ARGS(page_list));
+DECLARE_HOOK(android_vh_page_trylock_set,
+	TP_PROTO(struct page *page),
+	TP_ARGS(page));
+DECLARE_HOOK(android_vh_page_trylock_clear,
+	TP_PROTO(struct page *page),
+	TP_ARGS(page));
 DECLARE_HOOK(android_vh_shrink_node_memcgs,
 	TP_PROTO(struct mem_cgroup *memcg, bool *skip),
 	TP_ARGS(memcg, skip));

mm/rmap.c

@@ -534,6 +534,7 @@ struct anon_vma *page_lock_anon_vma_read(struct page *page)
 	struct anon_vma *anon_vma = NULL;
 	struct anon_vma *root_anon_vma;
 	unsigned long anon_mapping;
+	bool success = false;
 
 	rcu_read_lock();
 	anon_mapping = (unsigned long)READ_ONCE(page->mapping);
@@ -556,7 +557,11 @@ struct anon_vma *page_lock_anon_vma_read(struct page *page)
 		}
 		goto out;
 	}
-
+	trace_android_vh_do_page_trylock(page, NULL, NULL, &success);
+	if (success) {
+		anon_vma = NULL;
+		goto out;
+	}
 	/* trylock failed, we got to sleep */
 	if (!atomic_inc_not_zero(&anon_vma->refcount)) {
 		anon_vma = NULL;
@@ -2409,6 +2414,7 @@ static void rmap_walk_file(struct page *page, struct rmap_walk_control *rwc,
 	struct address_space *mapping = page_mapping(page);
 	pgoff_t pgoff_start, pgoff_end;
 	struct vm_area_struct *vma;
+	bool got_lock = false, success = false;
 
 	/*
 	 * The page lock not only makes sure that page->mapping cannot
@@ -2423,8 +2429,16 @@ static void rmap_walk_file(struct page *page, struct rmap_walk_control *rwc,
 
 	pgoff_start = page_to_pgoff(page);
 	pgoff_end = pgoff_start + thp_nr_pages(page) - 1;
-	if (!locked)
-		i_mmap_lock_read(mapping);
+	if (!locked) {
+		trace_android_vh_do_page_trylock(page,
+					&mapping->i_mmap_rwsem, &got_lock, &success);
+		if (success) {
+			if (!got_lock)
+				return;
+		} else {
+			i_mmap_lock_read(mapping);
+		}
+	}
 	vma_interval_tree_foreach(vma, &mapping->i_mmap,
 			pgoff_start, pgoff_end) {
 		unsigned long address = vma_address(page, vma);

mm/vmscan.c

@@ -1257,15 +1257,19 @@ static enum page_references page_check_references(struct page *page,
 	int referenced_ptes, referenced_page;
 	unsigned long vm_flags;
 	bool should_protect = false;
+	bool trylock_fail = false;
 
 	trace_android_vh_page_should_be_protected(page, &should_protect);
 	if (unlikely(should_protect))
 		return PAGEREF_ACTIVATE;
 
+	trace_android_vh_page_trylock_set(page);
 	referenced_ptes = page_referenced(page, 1, sc->target_mem_cgroup,
 					  &vm_flags);
 	referenced_page = TestClearPageReferenced(page);
-
+	trace_android_vh_page_trylock_get_result(page, &trylock_fail);
+	if (trylock_fail)
+		return PAGEREF_KEEP;
 	/*
 	 * Mlock lost the isolation race with us.  Let try_to_unmap()
 	 * move the page to the unevictable list.
@@ -1645,6 +1649,7 @@ retry:
 			if (unlikely(PageTransHuge(page)))
 				flags |= TTU_SPLIT_HUGE_PMD;
 
+			trace_android_vh_page_trylock_set(page);
 			try_to_unmap(page, flags);
 			if (page_mapped(page)) {
 				stat->nr_unmap_fail += nr_pages;
@@ -1757,6 +1762,7 @@ retry:
 					 * increment nr_reclaimed here (and
 					 * leave it off the LRU).
 					 */
+					trace_android_vh_page_trylock_clear(page);
 					nr_reclaimed++;
 					continue;
 				}
@@ -1795,8 +1801,10 @@ free_it:
 		 */
 		if (unlikely(PageTransHuge(page)))
 			destroy_compound_page(page);
-		else
+		else {
+			trace_android_vh_page_trylock_clear(page);
 			list_add(&page->lru, &free_pages);
+		}
 		continue;
 
 activate_locked_split:
@@ -2314,6 +2322,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
 		return 0;
 
 	nr_reclaimed = shrink_page_list(&page_list, pgdat, sc, &stat, false);
+	trace_android_vh_handle_failed_page_trylock(&page_list);
 
 	spin_lock_irq(&lruvec->lru_lock);
 	move_pages_to_lru(lruvec, &page_list);
@@ -2437,7 +2446,7 @@ static void shrink_active_list(unsigned long nr_to_scan,
 		trace_android_vh_page_referenced_check_bypass(page, nr_to_scan, lru, &bypass);
 		if (bypass)
 			goto skip_page_referenced;
-
+		trace_android_vh_page_trylock_set(page);
 		if (page_referenced(page, 0, sc->target_mem_cgroup,
 				    &vm_flags)) {
 			/*
@@ -2450,11 +2459,13 @@ static void shrink_active_list(unsigned long nr_to_scan,
 			 * so we ignore them here.
 			 */
 			if ((vm_flags & VM_EXEC) && page_is_file_lru(page)) {
+				trace_android_vh_page_trylock_clear(page);
 				nr_rotated += thp_nr_pages(page);
 				list_add(&page->lru, &l_active);
 				continue;
 			}
 		}
+		trace_android_vh_page_trylock_clear(page);
 skip_page_referenced:
 		ClearPageActive(page);	/* we are de-activating */
 		SetPageWorkingset(page);