fix div by zero (#76334)

github-actions[bot] · Maoni0 · web-flow · commit 9930d32d106d · 2022-09-28T17:58:33.000-07:00
Co-authored-by: Maoni0 &lt;maoni@microsoft.com&gt;
diff --git a/src/coreclr/gc/gc.cpp b/src/coreclr/gc/gc.cpp
@@ -3171,7 +3171,8 @@ gc_heap::dt_high_frag_p (gc_tuning_point tp,
 #ifndef MULTIPLE_HEAPS
                 if (gen_number == max_generation)
                 {
-                    float frag_ratio = (float)(dd_fragmentation (dynamic_data_of (max_generation))) / (float)generation_size (max_generation);
+                    size_t maxgen_size = generation_size (max_generation);
+                    float frag_ratio = (maxgen_size ? ((float)dd_fragmentation (dynamic_data_of (max_generation)) / (float)maxgen_size) : 0.0f);
                     if (frag_ratio > 0.65)
                     {
                         dprintf (GTC_LOG, ("g2 FR: %d%%", (int)(frag_ratio*100)));
@@ -3183,7 +3184,8 @@ gc_heap::dt_high_frag_p (gc_tuning_point tp,
                 ret = (fr > dd_fragmentation_limit(dd));
                 if (ret)
                 {
-                    fragmentation_burden = (float)fr / generation_size (gen_number);
+                    size_t gen_size = generation_size (gen_number);
+                    fragmentation_burden = (gen_size ? ((float)fr / (float)gen_size) : 0.0f);
                     ret = (fragmentation_burden > dd_v_fragmentation_burden_limit (dd));
                 }
                 dprintf (GTC_LOG, ("h%d: gen%d, frag is %Id, alloc effi: %d%%, unusable frag is %Id, ratio is %d",

Original file line number	Diff line number	Diff line change
`@@ -3171,7 +3171,8 @@ gc_heap::dt_high_frag_p (gc_tuning_point tp,`
`3171`	`3171`	`#ifndef MULTIPLE_HEAPS`
`3172`	`3172`	`if (gen_number == max_generation)`
`3173`	`3173`	`{`
`3174`		`- float frag_ratio = (float)(dd_fragmentation (dynamic_data_of (max_generation))) / (float)generation_size (max_generation);`
	`3174`	`+ size_t maxgen_size = generation_size (max_generation);`
	`3175`	`+ float frag_ratio = (maxgen_size ? ((float)dd_fragmentation (dynamic_data_of (max_generation)) / (float)maxgen_size) : 0.0f);`
`3175`	`3176`	`if (frag_ratio > 0.65)`
`3176`	`3177`	`{`
`3177`	`3178`	`dprintf (GTC_LOG, ("g2 FR: %d%%", (int)(frag_ratio*100)));`
`@@ -3183,7 +3184,8 @@ gc_heap::dt_high_frag_p (gc_tuning_point tp,`
`3183`	`3184`	`ret = (fr > dd_fragmentation_limit(dd));`
`3184`	`3185`	`if (ret)`
`3185`	`3186`	`{`
`3186`		`- fragmentation_burden = (float)fr / generation_size (gen_number);`
	`3187`	`+ size_t gen_size = generation_size (gen_number);`
	`3188`	`+ fragmentation_burden = (gen_size ? ((float)fr / (float)gen_size) : 0.0f);`
`3187`	`3189`	`ret = (fragmentation_burden > dd_v_fragmentation_burden_limit (dd));`
`3188`	`3190`	`}`
`3189`	`3191`	`dprintf (GTC_LOG, ("h%d: gen%d, frag is %Id, alloc effi: %d%%, unusable frag is %Id, ratio is %d",`