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lscpu was working after all... oh, and I can count boot cycles with gem5 much more easily

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Ciro Santilli
2018-02-28 14:33:23 +00:00
parent 7228f75ac7
commit 567515c067
1 changed files with 25 additions and 3 deletions
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README.adoc
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@@ -1089,7 +1089,19 @@ A friend told me this but I haven't tried it yet:
* `qemu/docs/tracing.txt` and `qemu/docs/replay.txt` * `qemu/docs/tracing.txt` and `qemu/docs/replay.txt`
* https://stackoverflow.com/questions/39149446/how-to-use-qemus-simple-trace-backend/46497873#46497873 * https://stackoverflow.com/questions/39149446/how-to-use-qemus-simple-trace-backend/46497873#46497873
Best attempt so far: Results:
[options="header"]
|===
|Commit |Arch |Simulator |Instruction count
|7228f75ac74c896417fb8c5ba3d375a14ed4d36b |arm |QEMU |680k
|7228f75ac74c896417fb8c5ba3d375a14ed4d36b |arm |gem5 AtomicSimpleCPU |160M
|7228f75ac74c896417fb8c5ba3d375a14ed4d36b |arm |gem5 HPI |155M
|7228f75ac74c896417fb8c5ba3d375a14ed4d36b |x86_64 |QEMU |3M
|7228f75ac74c896417fb8c5ba3d375a14ed4d36b |x86_64 |gem5 AtomicSimpleCPU |528M
|===
QEMU:
.... ....
time ./run -n -e 'init=/poweroff.out' -- -trace exec_tb,file=trace time ./run -n -e 'init=/poweroff.out' -- -trace exec_tb,file=trace
@@ -1099,6 +1111,15 @@ sed '/0x1000000/q' trace.txt >trace-boot.txt
wc -l trace-boot.txt wc -l trace-boot.txt
.... ....
gem5:
....
./run -a arm -g -e 'init=/eval.sh - lkmc_eval="m5 exit"' -n
# Or:
# ./run -a arm -g -e 'init=/eval.sh - lkmc_eval="m5 exit"' -n -- --cpu-type=HPI --caches
grep sim_insts m5out/stats.txt
....
Notes: Notes:
* `-n` is a good idea to reduce the chances that you send unwanted non-deterministic mouse or keyboard clicks to the VM. * `-n` is a good idea to reduce the chances that you send unwanted non-deterministic mouse or keyboard clicks to the VM.
@@ -1143,6 +1164,7 @@ grep -n 4003a0 trace.txt
.... ....
+ +
I have observed a single match for that instruction, so it must be the init, and there were only 20k instructions after it, so the impact is negligible. I have observed a single match for that instruction, so it must be the init, and there were only 20k instructions after it, so the impact is negligible.
* gem5 simulates memory latencies. So I think that the CPU loops idle while waiting for memory, and counts will be higher.
This works because we have already done the following with QEMU: This works because we have already done the following with QEMU:
@@ -1698,8 +1720,8 @@ but for some reason the Linux kernel is not seeing the cache sizes:
Behaviour breakdown: Behaviour breakdown:
* arm QEMU and gem5 (both `AtomicSimpleCPU` or `HPI`), x86 gem5: `/sys` files don't exist, and `getconf` values empty * arm QEMU and gem5 (both `AtomicSimpleCPU` or `HPI`), x86 gem5: `/sys` files don't exist, and `getconf` and `lscpu` value empty
* x86 QEMU: `/sys` files exist, but `getconf` values still empty * x86 QEMU: `/sys` files exist, but `getconf` and `lscpu` values still empty
===== gem5 memory latency ===== gem5 memory latency