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pingcap · Jul 11, 2022 · 0326579 · 0326579
1 parent 0acd1dd
commit 0326579
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Showing 2 changed files with 7 additions and 4 deletions.
diff --git a/sessionctx/variable/session.go b/sessionctx/variable/session.go
@@ -1166,9 +1166,9 @@ type SessionVars struct {
 	// RequestSourceType is the type of inner request.
 	RequestSourceType string
 
-	// MemoryDebugModeThreshold indicated the memory debug mode.
+	// MemoryDebugModeThreshold indicated the trigger threshold of memory tracking accuracy check.
 	MemoryDebugModeThreshold int64
-
+	// MemoryDebugModeRatio indicated the allowable bias ratio of memory tracking accuracy check.
 	MemoryDebugModeRatio int64
 }
 

diff --git a/sessionctx/variable/tidb_vars.go b/sessionctx/variable/tidb_vars.go
@@ -685,9 +685,12 @@ const (
 	// TiDBSimplifiedMetrics controls whether to unregister some unused metrics.
 	TiDBSimplifiedMetrics = "tidb_simplified_metrics"
 
-	// TiDBMemoryDebugModeThreshold is used to set tidb memory debug mode.
+	// TiDBMemoryDebugModeThreshold is used to set tidb memory debug mode trigger threshold.
+	// When set to 0, the function is disabled.
+	// When set to a negative integer, use memory debug mode 1 to detect the issue of frequent allocation and release of memory.
+	// When set to a positive integer, use memory debug mode 2 to detect the issue of memory tracking inaccurate.
 	TiDBMemoryDebugModeThreshold = "tidb_memory_debug_mode_threshold"
-	// TiDBMemoryDebugModeRatio is used
+	// TiDBMemoryDebugModeRatio is used set tidb memory debug mode bias ratio. Treat memory bias less than this ratio as noise.
 	TiDBMemoryDebugModeRatio = "tidb_memory_debug_mode_ratio"
 )