fs: only send IPI to invalidate LRU BH when needed
[~shefty/rdma-dev.git] / fs / buffer.c
index 70e2017edd70e68c9958d49f1692f3401013df92..36d66653b93191c9c13c21e74dea6f511a6ac9ab 100644 (file)
@@ -1384,10 +1384,23 @@ static void invalidate_bh_lru(void *arg)
        }
        put_cpu_var(bh_lrus);
 }
+
+static bool has_bh_in_lru(int cpu, void *dummy)
+{
+       struct bh_lru *b = per_cpu_ptr(&bh_lrus, cpu);
+       int i;
        
+       for (i = 0; i < BH_LRU_SIZE; i++) {
+               if (b->bhs[i])
+                       return 1;
+       }
+
+       return 0;
+}
+
 void invalidate_bh_lrus(void)
 {
-       on_each_cpu(invalidate_bh_lru, NULL, 1);
+       on_each_cpu_cond(has_bh_in_lru, invalidate_bh_lru, NULL, 1, GFP_KERNEL);
 }
 EXPORT_SYMBOL_GPL(invalidate_bh_lrus);