Tag Archives: Linux

Build Ampere CentOS Kernel

Posted by on 2022/03/17 No comments

Personal Note

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Ubuntu 18.04 ARM64 DPDK in VM (QEMU)

Posted by on 2019/08/19 No comments

DPDK is a very popular infrastructure in high speed packet process domain, some applications will used the same architecture to process packet, like EPC.

For Ubuntu 18.04, it used dpdk 17.11, it not good for some other application like dpdk pktgen, but enough for testpmd and l3fwd test. here is some personal note for setup whole environment.

DPDK in QEMU archeticture
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[virtualbox] ftdi_sio ttyUSB0: failed to get modem status: -110

Posted by on 2018/01/22 No comments

環境是 Linux 下執行 VirtualBox

如果是使用 ftdi driver , 常常會在 Linux kernel 內出現

ftdi_sio ttyUSB0: failed to get modem status: -110

這個問題困擾我很久了, 解決方法是在系統內將 USB 2.0 的設定改成 USB 3.0, 如圖

這樣就可以解決問題了, 簡單吧.

Linux Kernel 4.7 PPTP pass through issue

Posted by on 2016/09/02 1 comment

升級到 Linux kernel 4.7 之後, 突然 PPTP pass through 有問題.
有人提供了解決方案

在 /etc/sysctl.conf 加上

net.netfilter.nf_conntrack_helper=1

這樣就可以了, 不知道為什麼預設值改了.
ref.
Bug 152101 – Updating from 4.6.4 to 4.7 breaks “pptp pass through”

SIGALARM / timer_create 造成 CPU sys 100% 的問題

Posted by on 2016/09/01 No comments

最近遇到一個怪問題, 某一隻程式跑起來的時候, 有一定的機率 sys 佔有率是 100%

Cpu0  :  0.0%us,100.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st

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CentOS 5.9 x64 + T420s Xorg crash problem.

Posted by on 2014/08/28 2 comments

OS CentOS 5.9 x64
NB: Thinkpad T420s

Xorg.0.log
==
(II) Module ddc: vendor=”X.Org Foundation”
compiled for 7.1.1, module version = 1.0.0
ABI class: X.Org Video Driver, version 1.0
(II) VESA(0): VESA VBE DDC supported
(II) VESA(0): VESA VBE DDC Level none
(II) VESA(0): VESA VBE DDC transfer in appr. 0 sec.
(II) VESA(0): VESA VBE DDC read failed
(II) VESA(0): VESA VBE PanelID read successfully
(II) VESA(0): PanelID returned panel resolution 1600×900

Backtrace:
0: X(xf86SigHandler+0x71) [0x4868d1]
1: /lib64/libc.so.6 [0x2b64029a72d0]
2: /usr/lib64/xorg/modules/drivers/vesa_drv.so [0x2b6404b3ef09]
3: X(InitOutput+0x9cd) [0x46431d]
4: X(main+0x26f) [0x4335ef]
5: /lib64/libc.so.6(__libc_start_main+0xf4) [0x2b64029949c4]
6: X(FontFileCompleteXLFD+0x241) [0x432aa9]

Fatal server error:
Caught signal 11. Server aborting
==

Solution:
$ yum install fonts-chinese.noarch

Why, I don’t know.

[Gentoo] 電腦升級案 32bit -> 64bit Linux

Posted by on 2013/12/26 3 comments

最近發現有一台電腦己經有點舊了, 首先是電源供應器的風扇掛了, 這個電源供應該應該有十年了, 印像中還沒有支援新的 ATX 接頭, 當年好像是用很便宜的價格從瘋狂賣客買的.
將電源風扇換成磁浮風扇之後, 似乎有好一點, 不過問題是, 很難開機, 還好這一台是一開就不關的 Server.
但是最近工作型態改變, 而且我買了一個瓦特計(像這樣), 沒事就在量電腦的電量. 發現常常使用的測試用電腦瓦特數非常高, Intel Q6600 + ATI 4850 要耗用 200W 左右.

所以最近就在找下一代的解決方案. 目標高效低功耗PC.
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kernel rootwait option

Posted by on 2012/11/09 2 comments

之前都不知道 Linux kernel 有 rootwait option, 比 rootdelay=? 好用多了.

尤其是用 usb or mmc 之類的 device 當作 root, 常用於 embedded system .
(其實我也少用, 都混 IC vendor , rootwait 這種東西就交給系統廠去處理).

Example Command
[TEXT]
CONFIG_CMDLINE=”root=/dev/mmcblk0p1 rw init=/sbin/init mem=256M console=ttyS0,38400 rootwait”
[/TEXT]

[Gentoo] 升級 KDE 4.9 的問題.

Posted by on 2012/08/13 No comments

都什麼年代了, 還在手賤亂升 KDE 系統…..

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