Update unit test to avoid timeout (#10950)

Summary:
Update unit test to avoid timeout

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10950

Reviewed By: hx235

Differential Revision: D41258892

Pulled By: akankshamahajan15

fbshipit-source-id: cbfe94da63e9e54544a307845deb79ba42458301

file/prefetch_test.cc

@@ -1590,54 +1590,6 @@ TEST_P(PrefetchTest, ReadAsyncWithPosixFS) {
     ASSERT_EQ(get_perf_context()->number_async_seek, 0);
   }
 
-  {
-    // Read the keys using seek.
-    {
-      ASSERT_OK(options.statistics->Reset());
-      get_perf_context()->Reset();
-
-      auto iter = std::unique_ptr<Iterator>(db_->NewIterator(ro));
-      int num_keys = 0;
-      iter->Seek(BuildKey(450));
-      while (iter->Valid()) {
-        ASSERT_OK(iter->status());
-        num_keys++;
-        iter->Next();
-      }
-      ASSERT_OK(iter->status());
-
-      iter->Seek(BuildKey(450));
-      while (iter->Valid()) {
-        ASSERT_OK(iter->status());
-        num_keys++;
-        iter->Prev();
-      }
-
-      ASSERT_EQ(num_keys, total_keys + 1);
-      ASSERT_GT(buff_prefetch_count, 0);
-
-      // Check stats to make sure async prefetch is done.
-      {
-        HistogramData async_read_bytes;
-        options.statistics->histogramData(ASYNC_READ_BYTES, &async_read_bytes);
-        HistogramData prefetched_bytes_discarded;
-        options.statistics->histogramData(PREFETCHED_BYTES_DISCARDED,
-                                          &prefetched_bytes_discarded);
-
-        // Not all platforms support iouring. In that case, ReadAsync in posix
-        // won't submit async requests.
-        if (read_async_called) {
-          ASSERT_GT(async_read_bytes.count, 0);
-          ASSERT_GT(get_perf_context()->number_async_seek, 0);
-        } else {
-          ASSERT_EQ(async_read_bytes.count, 0);
-          ASSERT_EQ(get_perf_context()->number_async_seek, 0);
-        }
-        ASSERT_GT(prefetched_bytes_discarded.count, 0);
-      }
-    }
-  }
-
   SyncPoint::GetInstance()->DisableProcessing();
   SyncPoint::GetInstance()->ClearAllCallBacks();