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Satoru Takeuchi satoru-takeuchi

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View kernelvm探検隊online part2アンケートコメント
皆さんスゲー
非常に面白く参考になりました。
おもしろかったです
元気いただきました!
yasssss
View sched.go
package main
import (
"fmt"
"log"
"os"
"strconv"
"sync"
"time"
)
View sched.c
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>
#define NLOOP_FOR_ESTIMATION 1000000000UL
@satoru-takeuchi
satoru-takeuchi / rook_and_cephadm_performance_comparison.md
Last active Jan 26, 2021
rook and cephadm performance comparison
View rook_and_cephadm_performance_comparison.md

What is measured

The elapsed time to create 1 MON, 1 MGR, and 1 OSD Ceph cluster in one node. All container is in local host.

result

  • rook
    • launching a one node k8s cluster by kubeadm: 84s
    • launching a rook/ceph cluster on top of this k8s cluster: 64s
View workaround-for-Ryzen-random-SEGV-problem
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
View freq
#!/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
View cpusoc.freq.txt
2200000
2200000
2200000
2200000
2200000
2200000
2200000
View nocpunosoc.freq
2200000
2200000
2200000
2200000
2200000
2200000
2200000
View ryzen-random-corrected-mce-about-uop-cache
...
[ 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.
View ryzen-problem-repro3
#!/bin/bash
export LANG=C
if [ $# -ge 1 ] ; then
CONCURRENCY=$1
else
CONCURRENCY=16
fi