Why buffered writes are sometimes stalledMany people think buffered write (write()/pwrite()) is fast because it does not do disk access. But this is not always true. Buffered write sometimes does disk access by itself, or waits for some disk accesses by other threads. Here are three common cases where write() takes longer time (== causing stalls). 1. Read Modify Write Suppose the following logic. Opening aaa.dat without O_DIRECT/O_SYNC,
