'be the Geek!'에 해당하는 글 544건



CONFIG_DEBUG_INFO=y 


yum install kernel-debuginfo 


yum install crash


add 'log_buf_len=5M crashkernel=384M-2G:64M,2G-:256M' in grub  and reboot


# service kdump start


// some crash


# crash /usr/lib/debug/lib/modules/<kernel>/vmlinux   /var/crash/<timestamp>/vmcore


# cat /var/crash/127.0.xxxx/vmcore-dmesg.txt





check out  latest crash utility from https://github.com/crash-utility/crash.git


# crash /lib/modules/`uname -r`/build/vmlinux /var/crash/<timestamp>/vmcore


crash> bt -l

crash> dis -l __decision+125



$ gdb clustering.o

(gdb) disassemble /m __decision


 







WRITTEN BY
RootFriend
개인적으로... 나쁜 기억력에 도움되라고 만들게되었습니다.

,



$ sudo taskset 0x1 -c 0 ./lat_mem_rd -N 1 -P 1 20M 256

$ lshw



WRITTEN BY
RootFriend
개인적으로... 나쁜 기억력에 도움되라고 만들게되었습니다.

,

[ Reference : https://yunmingzhang.wordpress.com/2017/10/24/performance-counters-for-measuring-numa-ops/ ]


Some useful performance counters from ocperf measuring loads to remote and local DRAM, cache hits, and DRAM QPI traffic.

To get PMU tools, clone this directory

https://github.com/andikleen/pmu-tools

pmu-tools/ocperf.py stat -e

mem_load_uops_l3_hit_retired.xsnp_hit,

mem_load_uops_l3_hit_retired.xsnp_hitm,

mem_load_uops_l3_hit_retired.xsnp_none,

mem_load_uops_l3_miss_retired.remote_dram,

mem_load_uops_l3_miss_retired.remote_fwd,

mem_load_uops_l3_miss_retired.local_dram -I500 ./executable

This measures l3 cache hits, local DRAM and remote DRAM accesses (ocperf.py stat -e ). The operations are sampled at 500ms intervals with ( -I )

 

More documentation on the specifics

mem_load_uops_l3_hit_retired.xsnp_hit measures hits that come from cross core snoop (hit in the L2 of another core, could be because the cache line is dirty, the other cores currently owns it) 

mem_load_uops_l3_hit_retired.xsnp_hitm measures hits that come from the shared L3 directly (no snoop involved)

In general, if we are only doing reads, then we should mostly seeing direct read from L3 shared.

Official documentation in pmu-tools ocperf

  mem_load_uops_l3_hit_retired.xsnp_hit      

     Retired load uops which data sources were L3 and cross-core snoop

     hits in on-pkg core cache. (Supports PEBS) Errata: HSM26, HSM30

  mem_load_uops_l3_hit_retired.xsnp_hitm     

     Retired load uops which data sources were HitM responses from

     shared L3. (Supports PEBS) Errata: HSM26, HSM30

  mem_load_uops_l3_hit_retired.xsnp_miss     

     Retired load uops which data sources were L3 hit and cross-core

     snoop missed in on-pkg core cache. (Supports PEBS) Errata: HSM26,

     HSM30

  mem_load_uops_l3_hit_retired.xsnp_none     

     Retired load uops which data sources were hits in L3 without

     snoops required. (Supports PEBS) Errata: HSM26, HSM30

 

  mem_load_uops_l3_miss_retired.remote_fwd   

     Retired load uop whose Data Source was: forwarded from remote

     cache (Supports PEBS) Errata: HSM30

  mem_load_uops_l3_miss_retired.remote_hitm 

     Retired load uop whose Data Source was: Remote cache HITM

 

If we want to measure remote LLC reads, we can use offcore counters, such as

offcore_response.all_reads.llc_hit.any_response

To measure QPI traffic

pmu-tools/ucevent/ucevent.py –scale GB QPI_LL.QPI_DATA_BW   — ./executable

Sometimes this would complain about “./”. One way to get around it is to do — taskset -c 0-num_cores ./executable or add something before the “./”.

–scale GB sets the scale to GB, QPI data bandwidth shows the traffic between NUMA nodes.

QPI link goes between the two sockets. There are two in each direction (one for each memory controller) for a total of 4 links. This counter will show the traffic on all 4 links.  On the ones in Lanka, Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz, they are 15 GB/s per link. So max 30 GB/s between the two sockets. This is about 30% less than 40 GB/s local DRAM. This 30GB/s bandwidth therefore limits the remote DRAM bandwidth to 30 GB/s. 

However, a lot of applications are not bandwidth bounded. For latency bounded applications on the current Lanka set up, according to Vlad

local DRAM latency: 80 ns

QPI link latency : 40 ns,

as a result, remote DRAM latency: 80 ns + 40 ns = 120 ns, about 50% slower than local DRAM.

The 40 ns latency QPI link latency also imposes a non-trivial overhead for remote LLC access. A local LLC access is about 34.8-20 ns. So the 40 ns QPI link latency can potentially make a remote LLC as expensive as the local DRAM access.

toplev for measuring everything (see if it is memory bound)

pmu-tools/toplev.py -l2 -m -C2 -S — ./executable


WRITTEN BY
RootFriend
개인적으로... 나쁜 기억력에 도움되라고 만들게되었습니다.

,
너는 말이다. 한번쯤 그 긴 혀를 뽑힐 날이 있을 것이다.
언제나 번지르르하게 늘어놓고 그 실천은 엉망이다. 
오늘도 너는 열여섯 시간분의 계획을 세워놓고
겨우 열 시간분을 채우는 데 그쳤다.
쓰잘 것 없는 호승심에 충동된 여섯 시간을 낭비하였다.
이제 너를 위해 주문을 건다. 남은 날 중에서 단 하루라도
그 계획량을 채우지 않거든 너는 이 시험에서 떨어져라.
하늘이 있다면 그 하늘이 도와 반드시 떨어져라.
그리하여 주정뱅이 떠돌이로 낯선 길바닥에서 죽든
일찌감치 독약을 마시든 하라.
- 이문열 < 젊은 날의 초상 > 중에서 -



WRITTEN BY
RootFriend
개인적으로... 나쁜 기억력에 도움되라고 만들게되었습니다.

,

Windows 10

카테고리 없음 2018. 11. 30. 10:47

1) Searching All file contents with cortana

- search for "Indexing Options"

- Click "Advanced"

- Click "File Types" tab

- Under "How should this file be indexed?" select "Index Properties and File Contents."


WRITTEN BY
RootFriend
개인적으로... 나쁜 기억력에 도움되라고 만들게되었습니다.

,



1) modify '/etc/ssh/sshd_config' as follows

TCPKeepAlive yes

GatewayPorts yes

ClientAliveInterval 60

ClientAliveCountMax 999999999


2) based on "external_server -- firewall -- internal_server" structure,


we can run following command on internal_server


$ sudo ssh -fN -R *:7777:localhost:22 id@external_server_ip -p 2222


where sshd port for external_server_ip is 2222 and port 7777 can be any available ports on external_server. 


3) connection.


on external_server, we can run following command to connect internal_server


$ ssh localhost -p 7777







WRITTEN BY
RootFriend
개인적으로... 나쁜 기억력에 도움되라고 만들게되었습니다.

,


grub2list.sh


#!/bin/bash

awk -F\' '$1=="menuentry " {print i++ " : " $2}' /etc/grub2.cfg



edit 'GRUB_DEFAULT= XX' on '/etc/default/grub'


or


$ sudo grub2-set-default XX

$ sudo grub2-editenv list


or

$ sudo grub2-editenv list

$ sudo grub2-reboot 0



WRITTEN BY
RootFriend
개인적으로... 나쁜 기억력에 도움되라고 만들게되었습니다.

,



on 'cmd' program,


to enable safe mode

c:\> bcdedit /set {default} safeboot minimal

and reboot.


to enable normal mode

c:\>bcdedit  /deletevalue {default} safeboot

and reboot





WRITTEN BY
RootFriend
개인적으로... 나쁜 기억력에 도움되라고 만들게되었습니다.

,

윈도우 배우는중..

reference : https://support.microsoft.com/en-ca/help/12445/windows-keyboard-shortcuts



Copy, paste, and other general keyboard shortcuts

Press this keyTo do this
Ctrl + XCut the selected item
Ctrl + C (or Ctrl + Insert)Copy the selected item
Ctrl + V (or Shift + Insert)Paste the selected item
Ctrl + ZUndo an action
Alt + TabSwitch between open apps
Alt + F4Close the active item, or exit the active app
Windows logo key  + LLock your PC
Windows logo key  + DDisplay and hide the desktop
F2Rename the selected item
F3Search for a file or folder in File Explorer
F4Display the address bar list in File Explorer
F5Refresh the active window
F6Cycle through screen elements in a window or on the desktop
F10Activate the Menu bar in the active app
Alt + F8Show your password on the sign-in screen
Alt + EscCycle through items in the order in which they were opened
Alt + underlined letterPerform the command for that letter
Alt + EnterDisplay properties for the selected item
Alt + SpacebarOpen the shortcut menu for the active window
Alt + Left arrowGo back
Alt + Right arrowGo forward
Alt + Page UpMove up one screen
Alt + Page DownMove down one screen
Ctrl + F4Close the active document (in apps that are full-screen and let you have multiple documents open at the same time)
Ctrl + ASelect all items in a document or window
Ctrl + D (or Delete)Delete the selected item and move it to the Recycle Bin
Ctrl + R (or F5)Refresh the active window
Ctrl + YRedo an action
Ctrl + Right arrowMove the cursor to the beginning of the next word
Ctrl + Left arrowMove the cursor to the beginning of the previous word
Ctrl + Down arrowMove the cursor to the beginning of the next paragraph
Ctrl + Up arrowMove the cursor to the beginning of the previous paragraph
Ctrl + Alt + TabUse the arrow keys to switch between all open apps
Alt + Shift + arrow keysWhen a group or tile is in focus on the Start menu, move it in the direction specified
Ctrl + Shift + arrow keysWhen a tile is in focus on the Start menu, move it into another tile to create a folder
Ctrl + arrow keysResize the Start menu when it's open
Ctrl + arrow key (to move to an item) + SpacebarSelect multiple individual items in a window or on the desktop
Ctrl + Shift with an arrow keySelect a block of text
Ctrl + EscOpen Start
Ctrl + Shift + EscOpen Task Manager
Ctrl + ShiftSwitch the keyboard layout when multiple keyboard layouts are available
Ctrl + SpacebarTurn the Chinese input method editor (IME) on or off
Shift + F10Display the shortcut menu for the selected item
Shift with any arrow keySelect more than one item in a window or on the desktop, or select text in a document
Shift + DeleteDelete the selected item without moving it to the Recycle Bin first
Right arrowOpen the next menu to the right, or open a submenu
Left arrowOpen the next menu to the left, or close a submenu
EscStop or leave the current task

 

Windows logo key keyboard shortcuts

Press this keyTo do this
Windows logo key Open or close Start
Windows logo key  + AOpen Action center
Windows logo key  + BSet focus in the notification area
Windows logo key  + C
Open Cortana in listening mode

Notes
  • This shortcut is turned off by default. To turn it on, select Start  > Settings  > Cortana, and turn on the toggle under Let Cortana listen for my commands when I press the Windows logo key + C.
  • Cortana is available only in certain countries/regions, and some Cortana features might not be available everywhere. If Cortana isn't available or is turned off, you can still use search.
Windows logo key  + Shift + COpen the charms menu
Windows logo key  + DDisplay and hide the desktop
Windows logo key  + Alt + DDisplay and hide the date and time on the desktop
Windows logo key  + EOpen File Explorer
Windows logo key  + FOpen Feedback Hub and take a screenshot
Windows logo key  + GOpen Game bar when a game is open
Windows logo key  + HStart dictation
Windows logo key  + IOpen Settings

Windows logo key  + J

 Set focus to a Windows tip when one is available.

When a Windows tip appears, bring focus to the Tip.  Pressing the keyboard shortcuts again to bring focus to the element on the screen to which the Windows tip is anchored.
Windows logo key  + KOpen the Connect quick action
Windows logo key  + LLock your PC or switch accounts
Windows logo key  + MMinimize all windows
Windows logo key  + OLock device orientation
Windows logo key  + PChoose a presentation display mode
Windows logo key  + ROpen the Run dialog box
Windows logo key  + SOpen search
Windows logo key  + TCycle through apps on the taskbar
Windows logo key  + UOpen Ease of Access Center
Windows logo key  + VCycle through notifications
Windows logo key  + Shift + VCycle through notifications in reverse order
Windows logo key  + XOpen the Quick Link menu
Windows logo key  + YSwitch input between Windows Mixed Reality and your desktop
Windows logo key  + ZShow the commands available in an app in full-screen mode
Windows logo key  + period (.) or semicolon (;)Open emoji panel
Windows logo key  + comma (,)Temporarily peek at the desktop
Windows logo key  + PauseDisplay the System Properties dialog box
Windows logo key  + Ctrl + FSearch for PCs (if you're on a network)
Windows logo key  + Shift + MRestore minimized windows on the desktop
Windows logo key  + numberOpen the desktop and start the app pinned to the taskbar in the position indicated by the number. If the app is already running, switch to that app.
Windows logo key  + Shift + numberOpen the desktop and start a new instance of the app pinned to the taskbar in the position indicated by the number
Windows logo key  + Ctrl + numberOpen the desktop and switch to the last active window of the app pinned to the taskbar in the position indicated by the number
Windows logo key  + Alt + numberOpen the desktop and open the Jump List for the app pinned to the taskbar in the position indicated by the number
Windows logo key  + Ctrl + Shift + numberOpen the desktop and open a new instance of the app located at the given position on the taskbar as an administrator
Windows logo key  + TabOpen Task view
Windows logo key  + Up arrowMaximize the window
Windows logo key  + Down arrowRemove current app from screen or minimize the desktop window
Windows logo key  + Left arrowMaximize the app or desktop window to the left side of the screen
Windows logo key  + Right arrowMaximize the app or desktop window to the right side of the screen
Windows logo key  + HomeMinimize all except the active desktop window (restores all windows on second stroke)
Windows logo key  + Shift + Up arrowStretch the desktop window to the top and bottom of the screen
Windows logo key  + Shift + Down arrowRestore/minimize active desktop windows vertically, maintaining width
Windows logo key  + Shift + Left arrow or Right arrowMove an app or window in the desktop from one monitor to another
Windows logo key  + SpacebarSwitch input language and keyboard layout
Windows logo key  + Ctrl + SpacebarChange to a previously selected input
Windows logo key  + Ctrl + EnterOpen Narrator
Windows logo key  + Plus (+)Open Magnifier
Windows logo key  + forward slash (/)Begin IME reconversion
Windows logo key  + Ctrl + VOpen shoulder taps

 

Command Prompt keyboard shortcuts

Press this keyTo do this
Ctrl + C (or Ctrl + Insert)Copy the selected text
Ctrl + V (or Shift + Insert)Paste the selected text
Ctrl + MEnter Mark mode
Alt + selection keyBegin selection in block mode
Arrow keysMove the cursor in the direction specified
Page upMove the cursor by one page up
Page downMove the cursor by one page down
Ctrl + Home (Mark mode)Move the cursor to the beginning of the buffer
Ctrl + End (Mark mode)Move the cursor to the end of the buffer
Ctrl + Up arrowMove up one line in the output history
Ctrl + Down arrowMove down one line in the output history
Ctrl + Home (History navigation)If the command line is empty, move the viewport to the top of the buffer. Otherwise, delete all the characters to the left of the cursor in the command line.
Ctrl + End (History navigation)If the command line is empty, move the viewport to the command line. Otherwise, delete all the characters to the right of the cursor in the command line.

 

Dialog box keyboard shortcuts

Press this keyTo do this
F4Display the items in the active list
Ctrl + TabMove forward through tabs
Ctrl + Shift + TabMove back through tabs
Ctrl + number (number 1–9)Move to nth tab
TabMove forward through options
Shift + TabMove back through options
Alt + underlined letterPerform the command (or select the option) that is used with that letter
SpacebarSelect or clear the check box if the active option is a check box
BackspaceOpen a folder one level up if a folder is selected in the Save As or Open dialog box
Arrow keysSelect a button if the active option is a group of option buttons

 

File Explorer keyboard shortcuts

Press this keyTo do this
Alt + DSelect the address bar
Ctrl + ESelect the search box
Ctrl + FSelect the search box
Ctrl + NOpen a new window
Ctrl + WClose the active window
Ctrl + mouse scroll wheelChange the size and appearance of file and folder icons
Ctrl + Shift + EDisplay all folders above the selected folder
Ctrl + Shift + NCreate a new folder
Num Lock + asterisk (*)Display all subfolders under the selected folder
Num Lock + plus (+)Display the contents of the selected folder
Num Lock + minus (-)Collapse the selected folder
Alt + PDisplay the preview panel
Alt + EnterOpen the Properties dialog box for the selected item
Alt + Right arrowView the next folder
Alt + Up arrowView the folder that the folder was in
Alt + Left arrowView the previous folder
BackspaceView the previous folder
Right arrowDisplay the current selection (if it's collapsed), or select the first subfolder
Left arrowCollapse the current selection (if it's expanded), or select the folder that the folder was in
EndDisplay the bottom of the active window
HomeDisplay the top of the active window
F11Maximize or minimize the active window

 

Virtual desktops keyboard shortcuts

Press this keyTo do this
Windows logo key  + TabOpen Task view
Windows logo key  + Ctrl + DAdd a virtual desktop
Windows logo key  + Ctrl + Right arrowSwitch between virtual desktops you’ve created on the right
Windows logo key  + Ctrl + Left arrowSwitch between virtual desktops you’ve created on the left
Windows logo key  + Ctrl + F4Close the virtual desktop you're using

 

Taskbar keyboard shortcuts

Press this keyTo do this
Shift + click a taskbar buttonOpen an app or quickly open another instance of an app
Ctrl + Shift + click a taskbar buttonOpen an app as an administrator
Shift + right-click a taskbar buttonShow the window menu for the app
Shift + right-click a grouped taskbar buttonShow the window menu for the group
Ctrl + click a grouped taskbar buttonCycle through the windows of the group

 

Settings keyboard shortcuts

Press this keyTo do this
Windows logo key  + IOpen settings
BackspaceGo back to the settings home page
Type on any page with search boxSearch settings

 



WRITTEN BY
RootFriend
개인적으로... 나쁜 기억력에 도움되라고 만들게되었습니다.

,

On ubuntu,


$ sudo locale-gen "en_US.UTF-8"

$ sudo dpkg-reconfigure locales


or simply add follows on "/etc/environment"


LC_ALL=en_US.UTF-8
LANG=en_US.UTF-8




WRITTEN BY
RootFriend
개인적으로... 나쁜 기억력에 도움되라고 만들게되었습니다.

,