Hello.
Suppose I have 4 addresses going to cache from cpu, A1, A2, A3 and A4. All are read requests.
Assume, my L1 cache is blocking.
Now, load store unit will first sent A1.
if it is a miss, the L1 will send it to L2. If it is a L2 hit, it will send the data back to L1, then L1 will send it back to cpu.
My question is, when will A2 be sent ?
-
When the memsideport of cpu becomes available, meaning once the L1 has received the A1 (and trying to determine hit/miss etc) ?
In this case, what will be the delay ? The latency of the crossbar/bus connecting L1 and L2 ?
-
Or will the cpu wait until it has received the data for A1 from the L1 ? Meaning at any given cycle, that cache object can deal with one single request ?
Also, can the cache in gem5 send multiple misses to lower level memories in the same cycle (assuming all MSHR misses)?
Hello.
Suppose I have 4 addresses going to cache from cpu, A1, A2, A3 and A4. All are read requests.
Assume, my L1 cache is blocking.
Now, load store unit will first sent A1.
if it is a miss, the L1 will send it to L2. If it is a L2 hit, it will send the data back to L1, then L1 will send it back to cpu.
My question is, when will A2 be sent ?
1) When the memsideport of cpu becomes available, meaning once the L1 has received the A1 (and trying to determine hit/miss etc) ?
In this case, what will be the delay ? The latency of the crossbar/bus connecting L1 and L2 ?
2) Or will the cpu wait until it has received the data for A1 from the L1 ? Meaning at any given cycle, that cache object can deal with one single request ?
Also, can the cache in gem5 send multiple misses to lower level memories in the same cycle (assuming all MSHR misses)?
