From d5b51082188557197d483ba699b62973c70572cc Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ciro=20Santilli=20=E5=85=AD=E5=9B=9B=E4=BA=8B=E4=BB=B6=20?= =?UTF-8?q?=E6=B3=95=E8=BD=AE=E5=8A=9F?= Date: Fri, 15 May 2020 01:00:00 +0000 Subject: [PATCH] 29cea9b9cdf00b0577fb160da4d8d38ba33b7b51 --- index.html | 69 +++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 53 insertions(+), 16 deletions(-) diff --git a/index.html b/index.html index 0a1afb5..ec8a597 100644 --- a/index.html +++ b/index.html @@ -1213,7 +1213,7 @@ body.book #toc,body.book #preamble,body.book h1.sect0,body.book .sect1>h2{page-b
  • 19.16.2. gem5 ARM RSK
    • @@ -2925,6 +2925,9 @@ j = 0

  • the actual command nicely, indented and with arguments broken one per line, but with continuing backslashes so you can just copy paste into a terminal

    +
    +

    For setups that don’t support the newline e.g. Eclipse debugging, you can turn them off with --print-cmd-oneline

    +

  • ;: both a valid part of the Bash command, and a visual mark the end of the command

    @@ -8287,7 +8290,7 @@ pid=100
    -

    We choose DerivO3CPU because of the se.py assert:

    +

    We choose DerivO3CPU because of the se.py assert:

    @@ -21461,7 +21464,7 @@ class SystemXBar(CoherentXBar):

    BaseKvmCPU

  • -

    BaseSimpleCPU

    +

    BaseSimpleCPU: gem5 BaseSimpleCPU

    • @@ -21474,7 +21477,7 @@ class SystemXBar(CoherentXBar):
  • -

    MinorO3CPU

    +

    MinorO3CPU: gem5 MinorCPU

  • BaseO3CPU

    @@ -21482,6 +21485,10 @@ class SystemXBar(CoherentXBar): +
    • + + +
    +

    From this we see that there are basically only 4 C++ CPU models in gem5: Atomic, Timing, Minor and O3. All others are basically parametrizations of those base types.

    +

    19.16.1. List gem5 CPU types

    @@ -21590,20 +21603,11 @@ class SystemXBar(CoherentXBar):

    Implemented by Pierre-Yves Péneau from LIRMM, which is a research lab in Montpellier, France, in 2017.

    -
  • -

    O3_ARM_v7a: implemented by Ronald Dreslinski from the University of Michigan in 2012

    -
    -

    Not sure why it has v7a in the name, since I believe the CPUs are just the microarchitectural implementation of any ISA, and the v8 hello world did run.

    -
    -
    -

    The CLI option is named slightly differently as: --cpu-type O3_ARM_v7a_3.

    -
    -
    • -
    19.16.1.3. gem5 DeriveO3CPU
    +
    19.16.1.3. gem5 DerivO3CPU

    Generic out-of-order core. "O3" Stands for "Out Of Order"!

    @@ -21625,6 +21629,15 @@ class SystemXBar(CoherentXBar):
    +
  • +

    O3_ARM_v7a: implemented by Ronald Dreslinski from the University of Michigan in 2012

    +
    +

    Not sure why it has v7a in the name, since I believe the CPUs are just the microarchitectural implementation of any ISA, and the v8 hello world did run.

    +
    +
    +

    The CLI option is named slightly differently as: --cpu-type O3_ARM_v7a_3.

    +
    +
    • @@ -21817,7 +21830,15 @@ cd ..
    -

    To run and GDB step debug the executable, just copy the full command line from the output ./run, and configure it into Eclipse.

    +

    To run and GDB step debug the executable, just copy the full command line without newlines from your run command (Eclipse does not like newlines for the arguments), e.g.:

    +
    +
    +
    +
    ./run --emulator gem5 --print-cmd-oneline
    +
    +
    +
    +

    and configure it into Eclipse as usual.

    @@ -28295,7 +28316,17 @@ There are no non-locking atomic types or atomic primitives in POSIX: https://stackoverflow.com/questions/145270/calling-c-c-from-python/60374990#60374990

    -

    pybind11 is amazingly easy to use. But it also makes your builds really slow: pybind11 accounts for 50% of gem5 build time.

    +

    pybind11 is amazingly easy to use. But it can also make your builds really slow:

    +
    +
    +
    @@ -30559,6 +30590,9 @@ child after parent sleep

    userland/linux/sched_getcpu.c

  • +

    userland/linux/getcpu.c: a wrapper close the the syscall that also returns the current NUMA node

    +
    • +

  • userland/linux/sched_getcpu_barrier.c: this uses a barrier to ensure that gem5 will run each thread on one separate CPU

    • @@ -37928,6 +37962,9 @@ tail -n+1 ../linux-kernel-module-cheat-regression/*/gem5-bench-build-*.txt

    Ubuntu 19.10, GCC 9.2.1, LKMC 7c6bb29bc89ec3f1056c0680c3f08bd64018a7bc, gem5 d7d9bc240615625141cd6feddbadd392457e49eb (2020-02-18), ./build --arch aarch64 --gem5-worktree master --no-cache: 19m 33s TODO must investigate why it got so much worse.

    +

    Ubuntu 20.04, GCC 9.3.0, LKMC 6275f70ed8862d8fe4e58ca4524a6994d254be35, gem5 d9cb548d83fa81858599807f54b52e5be35a6b03 (2020-05-06), ./build --arch aarch64 --gem5-worktree master --no-cache: 28m!!! It’s out of control.

    +
    +

    Same but gem5 d7d9bc240615625141cd6feddbadd392457e49eb (2018-06-17) hacked with -Wnoerror: 11m 37s. So there was a huge regression in the last two years! We have to find it out.