satoru-takeuchi

o  Gnu C                  3.2                     # gcc --version
o  Gnu C                  3.2                     # gcc --version
o  Gnu C                  3.2                     # gcc --version
o  Gnu C                  3.2                     # gcc --version
o  Gnu C                  3.2                     # gcc --version
o  Gnu C                  3.2                     # gcc --version
o  Gnu C                  3.2                     # gcc --version
o  Gnu C                  3.2                     # gcc --version
o  Gnu C                  3.2                     # gcc --version
o  Gnu C                  3.2                     # gcc --version

satoru-takeuchi

#!/usr/bin/python3

import random, time, sys

progname = sys.argv[0]

def usage():
    sys.stderr.write("usage: {} <filename> <r|w> <s|r> <blocksize> <count>\n".format(progname))
    exit(1)

satoru-takeuchi

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <time.h>
#include <err.h>

static char *progname;

void show_usage(void)

satoru-takeuchi

#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <signal.h>
#include <pthread.h>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>

satoru-takeuchi

#!/usr/bin/python3

import matplotlib as mat

mat.use("Agg")

import matplotlib.pyplot as plt
import numpy as np
from scipy.interpolate import interp1d

satoru-takeuchi

Subject: [RFC] [PATCH] workaround for Ryzen random SEGV problem

Limit the range of the virtual address map for user process, from 47 bit (128TB)
to 46 bit (64TB). It prevent processes to high memory address which would
cause random semgentation fault and some other problems on Ryzen.

For more detaul, please see the following links for detail.

The discussions about this problem on AMD support community.
https://community.amd.com/thread/215773

satoru-takeuchi

#!/bin/bash

for ((i=0;1;i++)) ; do
    for ((i=0;i<16;i++)) ; do
        cat /sys/devices/system/cpu/cpu$i/cpufreq/cpuinfo_cur_freq
        cat /sys/devices/system/cpu/cpu$i/cpufreq/scaling_cur_freq
        echo
    done
    echo "======"
    sleep 1

satoru-takeuchi

2200000
2200000

2200000
2200000

2200000
2200000

2200000

satoru-takeuchi

2200000
2200000

2200000
2200000

2200000
2200000

2200000

satoru-takeuchi

...
[  627.958024] mce: [Hardware Error]: Machine check events logged
[  627.958027] [Hardware Error]: Corrected error, no action required.
[  627.958034] [Hardware Error]: CPU:13 (17:1:1) MC3_STATUS[-|CE|MiscV|-|-|-|-|SyndV|-]: 0x9820000000000150
[  627.958037] [Hardware Error]: IPID: 0x000300b000000000, Syndrome: 0x000000002a000503
[  627.958040] [Hardware Error]: Decode Unit Extended Error Code: 0
[  627.958041] [Hardware Error]: Decode Unit Error: uop cache tag parity error.
[  627.958044] [Hardware Error]: cache level: RESV, tx: INSN, mem-tx: IRD
[ 1250.624254] mce: [Hardware Error]: Machine check events logged
[ 1250.624258] [Hardware Error]: Corrected error, no action required.