diff --git a/h2o_hf/utils_lm_eval/modify_llama.py b/h2o_hf/utils_lm_eval/modify_llama.py
index ea037a5..511eae3 100644
--- a/h2o_hf/utils_lm_eval/modify_llama.py
+++ b/h2o_hf/utils_lm_eval/modify_llama.py
@@ -131,20 +131,40 @@ def forward(
         heavy_budget = int(self.heavy_budget_ratio * attn_weights.shape[-1])
         recent_budget = int(self.recent_budget_ratio * attn_weights.shape[-1])
 
-        # Heavy Hitter Mask
-        if heavy_budget > 0:
-            mask_bottom = local_heavy_hitter_mask(attn_weights, heavy_budget) # Default: No padding applied to input
-        else:
-            mask_bottom = torch.zeros_like(attn_weights, dtype=torch.bool)
+        
+        # # Heavy Hitter Mask (Based on local statistics)
+        # if heavy_budget > 0:
+        #     mask_bottom = local_heavy_hitter_mask(attn_weights, heavy_budget) # Default: No padding applied to input
+        # else:
+        #     mask_bottom = torch.zeros_like(attn_weights, dtype=torch.bool)
+
+        # ones = torch.ones_like(attn_weights, dtype=torch.bool)
+        # ones = torch.triu(ones, diagonal=-recent_budget)
+        # mask_bottom = torch.logical_or(mask_bottom, ones)
+
+        # mask_bottom = torch.tril(mask_bottom, diagonal=0)
+
+        # # mask_bottom = ones
+        # attn_weights[~mask_bottom] = torch.min(attention_mask)
+
+
+        
+        # Heavy Hitter Mask (Based on global statistics)
+        tmp_attn = nn.functional.softmax(attn_weights, dim=-1, dtype=torch.float32).to(attn_weights.dtype)
+        tmp_sum = torch.sum(tmp_attn, dim=-2) 
+        _, tmp_topk = tmp_sum.topk(k=heavy_budget, dim=-1)
+
+        zeros = torch.zeros_like(tmp_sum, dtype=torch.bool)
+        mask_bottom = zeros.scatter(-1, tmp_topk, True).unsqueeze(2)
+        mask_bottom = mask_bottom.expand(mask_bottom.shape[0], mask_bottom.shape[1], attn_weights.shape[-2], mask_bottom.shape[-1])
 
         ones = torch.ones_like(attn_weights, dtype=torch.bool)
+        ones = torch.tril(ones, diagonal=recent_budget)
         ones = torch.triu(ones, diagonal=-recent_budget)
         mask_bottom = torch.logical_or(mask_bottom, ones)
-
-        mask_bottom = torch.tril(mask_bottom, diagonal=0)
-
         # mask_bottom = ones
-        attn_weights[~mask_bottom] = torch.min(attention_mask)
+        attn_weights[~mask_bottom] = torch.finfo(attn_weights.dtype).min
+
 
         # upcast attention to fp32
         attn_weights = nn.functional.softmax(attn_weights, dim=-1, dtype=torch.float32).to(query_states.dtype)