- [Ref: http://publib.boulder.ibm.com/infocenter/aix/v6r1/index.jsp?topic=%2Fcom.ibm.aix.kdb%2Fdoc%2Fkdb%2Fkdb.htm]
- kdb command
- This command is implemented as an ordinary user-space program and is typically used for
- post-mortem analysis of a previously-crashed system by using a system dump file. The kdb command includes subcommands specific to the manipulation of system dumps.
- KDB kernel debugger
- - The KDB kernel debugger is integrated into the kernel and allows full control of the system while a debugging session is in progress. The KDB kernel debugger allows for traditional debugging tasks such as setting breakpoints and single-stepping through code.
- - KDB needs to be enabled when the system boots.
- - To check if the KDB is enabled or not, issue
$> bosdebug -L- Memory debugger off
Memory sizes 0
Network memory sizes 0
Kernel debugger off
Real Time Kernel off
Backtracking fault log on
Kernext Memory Tracking off
- - To create a kernel image with KDB enabled, issue
- $> bosdebug -D
- This will turn on the kernel debugger. You need to bosboot and reboot in order to take this effect.
- $> bosboot -a && reboot
- [After of about 20-30 mins, you will have a KDB enabled image}
- bosboot: Boot image is 49180 512 byte blocks.
- - KDB enabled kernel image is ready. All you gotto do now is, reboot.
- If you have HMC kinda machine (where you remotely try to reboot the machine), while booting, you can see Kernel Debugging is enabled.
- $> reboot
- -------------------------------------------------------------------------------
Welcome to AIX.
boot image timestamp: 11:02:54 12/26/2011
The current time and date: 11:18:52 12/26/2011
processor count: 1; memory size: 2048MB; kernel size: 28147575
boot device: /vdevice/v-scsi@30000003/disk@8100000000000000:2
kernel debugger setting: enabled
-------------------------------------------------------------------------------
Monday, February 6, 2012
Kernel Debugging
Saturday, February 4, 2012
Tuesday, October 11, 2011
Sample vimrc file
For vimdiff colorschemes:
- Download github & molokai like below
curl -fLo ~/.vim/colors/molokai.vim --create-dirs https://raw.githubusercontent.com/tomasr/molokai/master/colors/molokai.vim curl -fLo ~/.vim/colors/github.vim --create-dirs https://raw.githubusercontent.com/endel/vim-github-colorscheme/master/colors/github.vim
Then add the below in .vimrc file
if &diff
" colorscheme github
colorscheme molokai
endif<or> ":colorscheme github" diff mode
syntax enable
set incsearch
set nocompatible
set showcmd
set hlsearch
set ai
set si
set ts=4 sw=4 smarttab
set nu
"set nowrap
set formatoptions+=r
set softtabstop=4
set smartindent
set autoindent
set showmatch
"set cursorline
source $HOME/.vim/plugin/taglist.vim
source $HOME/.vim/plugin/comments.vim
"highlight DiffAdd term=reverse cterm=bold ctermbg=white ctermfg=black
"highlight DiffChange term=reverse cterm=bold ctermbg=cyan ctermfg=black
"highlight DiffText term=reverse cterm=bold ctermbg=gray ctermfg=black
"highlight DiffDelete term=reverse cterm=bold ctermbg=cyan ctermfg=black
nnoremap <silent> <F1> :TlistToggle<CR>
"map <C-v><C-v> : vs<cr>
"map <C-q> : q<cr>
command CDC lcd %:p:h
hi LineNr ctermfg=darkyellow
"hi Function ctermfg=cyan
hi Function ctermfg=yellow
"hi Type ctermfg=cyan
hi Type ctermfg=lightred
hi String ctermfg=darkgreen
"hi String ctermfg=150
hi Number ctermfg=brown
"hi Operator ctermfg=brown
hi Search ctermbg=yellow
hi Conditional ctermfg=green
hi Comment ctermfg=lightblue
"""
"if &term =~ "xterm\\|rxvt"
" use an orange cursor in insert mode
"let &t_SI = "\<Esc>]12;orange\x7"
" use a red cursor otherwise
"let &t_EI = "\<Esc>]12;red\x7"
"silent !echo -ne "\033]12;red\007"
"" reset cursor when vim exits
"autocmd VimLeave * silent !echo -ne "\033]112\007"
" use \003]12;gray\007 for gnome-terminal and rxvt up to version 9.21
"endif
highlight Cursor ctermfg=yellow ctermbg=black
"highlight iCursor guifg=white guibg=steelblue
"set guicursor=n-v-c:block-Cursor
"set guicursor+=i:ver100-iCursor
"set guicursor+=n-v-c:blinkon0
"set guicursor+=i:blinkwait10
"""
iab log_this #define LOG_THIS(format, ...) { \<CR>if (access("/harish", F_OK) != -1) { \<CR>char buf1[128] = {}; char buf2[256] = {}; \<CR>char tbuf[20] = {}; time_t now = time(0); struct tm *sTm = gmtime(&now); \<CR>strftime(tbuf, sizeof (tbuf), "%Y-%m-%d %H:%M:%S", sTm); \<CR>snprintf(buf1, sizeof (buf1), "[%s %s:%d]" format, tbuf, __func__, __LINE__, ##__VA_ARGS__); \<CR>snprintf(buf2, sizeof (buf2), "echo '%s' >> /harish_log", buf1); \<CR>system(buf2); } }
set incsearch
set nocompatible
set showcmd
set hlsearch
set ai
set si
set ts=4 sw=4 smarttab
set nu
"set nowrap
set formatoptions+=r
set softtabstop=4
set smartindent
set autoindent
set showmatch
"set cursorline
source $HOME/.vim/plugin/taglist.vim
source $HOME/.vim/plugin/comments.vim
"highlight DiffAdd term=reverse cterm=bold ctermbg=white ctermfg=black
"highlight DiffChange term=reverse cterm=bold ctermbg=cyan ctermfg=black
"highlight DiffText term=reverse cterm=bold ctermbg=gray ctermfg=black
"highlight DiffDelete term=reverse cterm=bold ctermbg=cyan ctermfg=black
nnoremap <silent> <F1> :TlistToggle<CR>
"map <C-v><C-v> : vs<cr>
"map <C-q> : q<cr>
command CDC lcd %:p:h
hi LineNr ctermfg=darkyellow
"hi Function ctermfg=cyan
hi Function ctermfg=yellow
"hi Type ctermfg=cyan
hi Type ctermfg=lightred
hi String ctermfg=darkgreen
"hi String ctermfg=150
hi Number ctermfg=brown
"hi Operator ctermfg=brown
hi Search ctermbg=yellow
hi Conditional ctermfg=green
hi Comment ctermfg=lightblue
"""
"if &term =~ "xterm\\|rxvt"
" use an orange cursor in insert mode
"let &t_SI = "\<Esc>]12;orange\x7"
" use a red cursor otherwise
"let &t_EI = "\<Esc>]12;red\x7"
"silent !echo -ne "\033]12;red\007"
"" reset cursor when vim exits
"autocmd VimLeave * silent !echo -ne "\033]112\007"
" use \003]12;gray\007 for gnome-terminal and rxvt up to version 9.21
"endif
highlight Cursor ctermfg=yellow ctermbg=black
"highlight iCursor guifg=white guibg=steelblue
"set guicursor=n-v-c:block-Cursor
"set guicursor+=i:ver100-iCursor
"set guicursor+=n-v-c:blinkon0
"set guicursor+=i:blinkwait10
"""
" Copyright abbreviations
iab cfn /*<CR>Function<CR><CR>Description<CR><CR>Parameter(s)<CR><CR>Return Value<CR>/<Up><Up><Up><Up><Up><Up>
iab todo // TODO Remove this
iab cpr Broadcom Proprietary and Confidential. Copyright © 2019 Broadcom.<CR>All Rights Reserved.<CR>The term “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.
iab testbin TOPDIR<TAB>= ../../..<CR>MAKEDIR<TAB>= $(TOPDIR)/make<CR><CR>include $(MAKEDIR)/Tools.make<CR>include $(MAKEDIR)/Targets.make<CR>include $(MAKEDIR)/Fabos.make<CR>include $(MAKEDIR)/Man.make<CR><CR>TESTBIN = testbin<CR>TESTBIN_SRCS = testbin.c<CR>TESTBIN_OBJS = $(TESTBIN_SRCS:.c=.o)<CR><CR>$(TESTBIN): $(TESTBIN_OBJS)<CR><TAB>$(CC) $(LDFLAGS) -o $@ $^ $(LDLIBS)<CR>all:: $(TESTBIN)<CR><CR>clean::<CR><TAB>rm $(TESTBIN) $(TESTBIN_OBJS)
iab log_this #define LOG_THIS(format, ...) { \<CR>if (access("/harish", F_OK) != -1) { \<CR>char buf1[128] = {}; char buf2[256] = {}; \<CR>char tbuf[20] = {}; time_t now = time(0); struct tm *sTm = gmtime(&now); \<CR>strftime(tbuf, sizeof (tbuf), "%Y-%m-%d %H:%M:%S", sTm); \<CR>snprintf(buf1, sizeof (buf1), "[%s %s:%d]" format, tbuf, __func__, __LINE__, ##__VA_ARGS__); \<CR>snprintf(buf2, sizeof (buf2), "echo '%s' >> /harish_log", buf1); \<CR>system(buf2); } }
function! LoadCscope()
let db = findfile("cscope.out", ".;")
if (!empty(db))
let path = strpart(db, 0, match(db, "/cscope.out$"))
set nocscopeverbose " suppress 'duplicate connection' error
exe "cs add " . db . " " . path
set cscopeverbose
" else add the database pointed to by environment variable
elseif $CSCOPE_DB != ""
cs add $CSCOPE_DB
endif
endfunction
"au BufEnter /* call LoadCscope()
" http://cscope.sourceforge.net/cscope_maps.vim
nmap <C-\>ss :cs find s <C-R>=expand("<cword>")<CR><CR>
"nmap <C-\>g :cs find g <C-R>=expand("<cword>")<CR><CR>
nmap <C-\>cc :cs find c <C-R>=expand("<cword>")<CR><CR>
nmap <C-\>tt :cs find t <C-R>=expand("<cword>")<CR><CR>
"nmap <C-\>e :cs find e <C-R>=expand("<cword>")<CR><CR>
nmap <C-\>ff :cs find f <C-R>=expand("<cfile>")<CR><CR>
"nmap <C-\>i :cs find i ^<C-R>=expand("<cfile>")<CR>$<CR>
"nmap <C-\>d :cs find d <C-R>=expand("<cword>")<CR><CR>
nmap <C-\>s :cs find s
nmap <C-\>g :cs find g
nmap <C-\>c :cs find c
nmap <C-\>t :cs find t
nmap <C-\>e :cs find e
nmap <C-\>f :cs find f
nmap <C-\>i :cs find i
nmap <C-\>d :cs find d
" quick fix options
nmap qf :set cscopequickfix=s-,c-,d-,i-,t-,e-
nmap noqf :set cscopequickfix=""
nmap cw :cwindow
nmap <C-\>ss :cs find s <C-R>=expand("<cword>")<CR><CR>
"nmap <C-\>g :cs find g <C-R>=expand("<cword>")<CR><CR>
nmap <C-\>cc :cs find c <C-R>=expand("<cword>")<CR><CR>
nmap <C-\>tt :cs find t <C-R>=expand("<cword>")<CR><CR>
"nmap <C-\>e :cs find e <C-R>=expand("<cword>")<CR><CR>
nmap <C-\>ff :cs find f <C-R>=expand("<cfile>")<CR><CR>
"nmap <C-\>i :cs find i ^<C-R>=expand("<cfile>")<CR>$<CR>
"nmap <C-\>d :cs find d <C-R>=expand("<cword>")<CR><CR>
nmap <C-\>s :cs find s
nmap <C-\>g :cs find g
nmap <C-\>c :cs find c
nmap <C-\>t :cs find t
nmap <C-\>e :cs find e
nmap <C-\>f :cs find f
nmap <C-\>i :cs find i
nmap <C-\>d :cs find d
" quick fix options
nmap qf :set cscopequickfix=s-,c-,d-,i-,t-,e-
nmap noqf :set cscopequickfix=""
nmap cw :cwindow
"function! AddCscope()
"echom "Adding CSCOPE file.. please wait"
"silent! exec "r!goto_base_ws"
":cs add cscope.files
"endfunction
"nnoremap <silent> <F3> :call AddCscope()<CR>
"nnoremap <F3> :! ~/bin/goto_base_ws && cd vobs/projects/springboard/fabos <CR>:cs add cscope.files<CR>
Thursday, June 9, 2011
Thursday, March 24, 2011
Socket Programming - Part 1
Reference: http://www.tenouk.com/cnlinuxsockettutorials.html
Port Numbers
- 16 bit integers
- So a maximum port numbers are 2^16 = 65536 (0 to 65535)
- Unique with a machine/IP address
- Each service/application/daemon will have their own port number
- Required to make a connection (along with its host IP address)
Server & Client Port Numbers
- Connection is defined by: (Server IP and Port number) + (Client IP and port number)
- Server Port numbers are low numbers in the range 1 - 1023 (called as WELL KNOWN PORT NUMBER)
- Accessible only by Administrators (roots, in linux)
- Used for authentication
- A server running on a well-known port lets the OS know what port it wants to listen on
- Normally, client port numbers are higher number starting at 1024
- Client normally simples lets the OS picks a new port that is not already in use.
Monday, March 7, 2011
Background and Foreground Process
1. When you run a command (process), you can make it to run as a background process using $<cmd> &
2. If you forget to make that command as background, and if you feel you should do it now, then
- Press CTRL+Z (Suspend that process)
- $> bg disown 1 (make that process to be a background
3. Now if you want to check the list of background processes, type $> jobs
4. If you want to bring the background process to foreground, then type
$> fg %1
Again to make it a background process,
$> bg %1
2. If you forget to make that command as background, and if you feel you should do it now, then
- Press CTRL+Z (Suspend that process)
- $> bg disown 1 (make that process to be a background
3. Now if you want to check the list of background processes, type $> jobs
4. If you want to bring the background process to foreground, then type
$> fg %1
Again to make it a background process,
$> bg %1
Monday, February 7, 2011
When properties screwed up
It will get you the default properties (color, font etc) for your editor.
Wednesday, August 25, 2010
Tuesday, August 24, 2010
Locks in Multi-processing/multi-thread programming
DeadLock:
A deadlock is a situation wherein two or more competing actions are each waiting for the other to finish, and thus neither ever does.
LiveLock:
A deadlock is a situation wherein two or more competing actions are each waiting for the other to finish, and thus neither ever does.
LiveLock:
A livelock is similar to a deadlock, except that the states of the processes involved in the livelock constantly change with regard to one another, none progressing. Livelock is a special case of resource starvation; the general definition only states that a specific process is not progressing.
A real-world example of livelock occurs when two people meet in a narrow corridor, and each tries to be polite by moving aside to let the other pass, but they end up swaying from side to side without making any progress because they both repeatedly move the same way at the same time.
Livelock is a risk with some algorithms that detect and recover from deadlock. If more than one process takes action, the deadlock detection algorithm can repeatedly trigger. This can be avoided by ensuring that only one process (chosen randomly or by priority) takes action.
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