From 2ee6d22383df887237d390e77f810c9d062160d7 Mon Sep 17 00:00:00 2001
From: Weizhen Wang <wangweizhen@pingcap.com>
Date: Thu, 13 Jun 2024 12:43:29 +0800
Subject: [PATCH] statistics: updating stats cache can trigger evict (#53979)

close pingcap/tidb#53742
---
 pkg/statistics/handle/cache/internal/lfu/BUILD.bazel |  2 +-
 .../handle/cache/internal/lfu/lfu_cache.go           |  1 +
 .../handle/cache/internal/lfu/lfu_cache_test.go      | 12 ++++++++++++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/pkg/statistics/handle/cache/internal/lfu/BUILD.bazel b/pkg/statistics/handle/cache/internal/lfu/BUILD.bazel
index 1e732998623ab..a435d8a974bc6 100644
--- a/pkg/statistics/handle/cache/internal/lfu/BUILD.bazel
+++ b/pkg/statistics/handle/cache/internal/lfu/BUILD.bazel
@@ -30,7 +30,7 @@ go_test(
     embed = [":lfu"],
     flaky = True,
     race = "on",
-    shard_count = 9,
+    shard_count = 10,
     deps = [
         "//pkg/statistics",
         "//pkg/statistics/handle/cache/internal/testutil",
diff --git a/pkg/statistics/handle/cache/internal/lfu/lfu_cache.go b/pkg/statistics/handle/cache/internal/lfu/lfu_cache.go
index d4299d19b45be..4b82355945aa2 100644
--- a/pkg/statistics/handle/cache/internal/lfu/lfu_cache.go
+++ b/pkg/statistics/handle/cache/internal/lfu/lfu_cache.go
@@ -207,6 +207,7 @@ func (s *LFU) onExit(val any) {
 	if s.closed.Load() {
 		return
 	}
+	s.triggerEvict()
 	// Subtract the memory usage of the table from the total memory usage.
 	s.addCost(-val.(*statistics.Table).MemoryUsage().TotalTrackingMemUsage())
 }
diff --git a/pkg/statistics/handle/cache/internal/lfu/lfu_cache_test.go b/pkg/statistics/handle/cache/internal/lfu/lfu_cache_test.go
index de690b8e06ca9..cb74e5fdcedb3 100644
--- a/pkg/statistics/handle/cache/internal/lfu/lfu_cache_test.go
+++ b/pkg/statistics/handle/cache/internal/lfu/lfu_cache_test.go
@@ -295,3 +295,15 @@ func TestMemoryControl(t *testing.T) {
 	lfu.wait()
 	require.Equal(t, int64(10)*(2*mockCMSMemoryUsage+mockCMSMemoryUsage), lfu.Cost())
 }
+
+func TestMemoryControlWithUpdate(t *testing.T) {
+	capacity := int64(100)
+	lfu, err := NewLFU(capacity)
+	require.NoError(t, err)
+	for i := 0; i < 100; i++ {
+		t1 := testutil.NewMockStatisticsTable(i, 1, true, false, false)
+		lfu.Put(1, t1)
+	}
+	time.Sleep(1 * time.Second)
+	require.Equal(t, int64(0), lfu.Cost())
+}