(Solved): Consider a computer that has two levels of cache (L1 and L2), a main memory (RAM), a disk, and the ...

Consider a computer that has two levels of cache (L1 and L2), a main memory (RAM), a disk, and the OS uses virtual memory (for the purposes of this problem, it means that if a word is not found in cache or RAM, then it's found on disk). It takes \( 1 \mathrm{nsec} \) to access the word from L1, \( 2 \mathrm{nsec} \) from L2, \( 10 \mathrm{nsec} \) from RAM, and \( 7 \mathrm{msec} \) from disk. L1 hit rate is \( 90 \% \). L2 hit rate is \( 95 \% \). Main memory hit rate is \( 99 \% \). What is the average time to access a word? A file whose file descriptor is fd contains the following sequence of bytes: 31415934211385321 The following system calls are made: lseek(fd, 4, SEEK, SET); // seeks to byte 4 in the file read(fd, \&buffer, 5) What does buffer contain after the read is complete?