From 87f8c82651925fcee86c1c3bdb4a5c6f71542ec3 Mon Sep 17 00:00:00 2001
From: zhouwenhao <zhouwenhao@xiaomi.com>
Date: Tue, 25 Apr 2023 11:06:46 +0800
Subject: [PATCH] ANDROID: vendor_hooks:vendor hook for
 madvise_cold_or_pageout_pte_range.

add vendor hook in madvise_cold_or_pageout_pte_range to control the
pages to be reclaimed more fine-grained.

Bug: 284808098
Signed-off-by: zhouwenhao <zhouwenhao@xiaomi.com>
Change-Id: I298fde436df192cea9b1541d857f3a46808e06f2
---
 drivers/android/vendor_hooks.c | 1 +
 include/trace/hooks/mm.h       | 4 +++-
 mm/madvise.c                   | 8 ++++++++
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/android/vendor_hooks.c b/drivers/android/vendor_hooks.c
index 9dd7ca30c71c..c2af4cefe2f6 100644
--- a/drivers/android/vendor_hooks.c
+++ b/drivers/android/vendor_hooks.c
@@ -306,3 +306,4 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_encrypt_page);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_init_aes_encrypt);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_skip_swap_map_write);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_post_image_save);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_madvise_cold_pageout_skip);
diff --git a/include/trace/hooks/mm.h b/include/trace/hooks/mm.h
index 793cdd14a8a2..fb0bc38380fa 100644
--- a/include/trace/hooks/mm.h
+++ b/include/trace/hooks/mm.h
@@ -98,10 +98,12 @@ DECLARE_HOOK(android_vh_si_mem_available_adjust,
 DECLARE_HOOK(android_vh_si_meminfo_adjust,
 	TP_PROTO(unsigned long *totalram, unsigned long *freeram),
 	TP_ARGS(totalram, freeram));
-
 DECLARE_RESTRICTED_HOOK(android_rvh_ctl_dirty_rate,
 	TP_PROTO(void *unused),
 	TP_ARGS(unused), 1);
+DECLARE_HOOK(android_vh_madvise_cold_pageout_skip,
+	TP_PROTO(struct vm_area_struct *vma, struct page *page, bool pageout, bool *need_skip),
+	TP_ARGS(vma, page, pageout, need_skip));
 
 struct mem_cgroup;
 DECLARE_HOOK(android_vh_mem_cgroup_alloc,
diff --git a/mm/madvise.c b/mm/madvise.c
index e96c04dc9123..f49a62a35827 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -438,6 +438,8 @@ regular_page:
 	flush_tlb_batched_pending(mm);
 	arch_enter_lazy_mmu_mode();
 	for (; addr < end; pte++, addr += PAGE_SIZE) {
+		bool need_skip = false;
+
 		ptent = *pte;
 
 		if (pte_none(ptent))
@@ -454,6 +456,12 @@ regular_page:
 		if (!page || is_zone_device_page(page))
 			continue;
 
+		trace_android_vh_madvise_cold_pageout_skip(vma, page, pageout,
+			&need_skip);
+
+		if (need_skip)
+			continue;
+
 		/*
 		 * Creating a THP page is expensive so split it only if we
 		 * are sure it's worth. Split it if we are only owner.