svn list logs between two tags

http://www.bernzilla.com/item.php?id=613

In short:

svn log -v --stop-on-copy file:///dev/svn/tags/MY_FIRST_TAG

(get r1)

svn log -v --stop-on-copy file:///dev/svn/tags/MY_SECOND_TAG
(get r2)


svn log -v -r42:79 file:///dev/svn/trunk
(r42 is r1, 79 is r2).

lock detection in Linux kernel

Lockdep:

http://lwn.net/Articles/321663/

http://lwn.net/Articles/185666/

install lxml on centos 4

http://community.webfaction.com/questions/10561/how-do-i-install-lxml-on-a-centos-4-server

http://www.gossamer-threads.com/lists/zope/dev/222745

http://www.niteoweb.com/blog/compiling-lxml-on-64bit-centos

sfdisk usage

http://mybrainhurts.com/blog/2009/01/sfdisk-is-bomb.html

git revert commits

short answer:
git revert  xxx ( xxx is the commit hash)

long answer:
http://www.kernel.org/pub/software/scm/git/docs/howto/revert-branch-rebase.html

Linux upstart

http://www.linuxplanet.com/linuxplanet/tutorials/7033/1

http://www.ibm.com/developerworks/linux/library/l-lpic1-v3-101-3/

update BIOS and nvram

http://www.pixelbeat.org/docs/bios/

Awk guide

An Awk Primer

http://www.vectorsite.net/tsawk.html

modify initrd in Linux

http://www.thegeekstuff.com/2009/07/how-to-view-modify-and-recreate-initrd-img/

http://www.alexonlinux.com/opening-and-modifying-the-initrd#changing_it

http://www.cyberciti.biz/tips/compiling-linux-kernel-26.html

http://ubuntuforums.org/showthread.php?t=1843448

http://comments.gmane.org/gmane.linux.redhat.release.rhel6/345

svn revert local file changes

svn revert -R

Buddy info on Linux

cat /proc/buddyinfo

shows the number of free entries. The order increased from left to right.

E.g


cat /proc/buddyinfo
Node 0, zone      DMA      0      1      1      2      2      1      0      0   1      1      3
Node 0, zone    DMA32   6251   5987   1236    279     36      2     13      0   0      0      0
Node 0, zone   Normal    848     96      4      4      3      1      1      1   0      0      0
Node 1, zone   Normal   2578    920    335   1563   1890   2239    569    393   116    4      0
Node 2, zone   Normal   5691   4461   4559    712    516     63     38    535   330    99     26
Node 3, zone   Normal   1874   1092    384    140     48     21     15     11   0      0      0

Linux Complete Fair Scheduler (CFS)

http://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt

http://publib.boulder.ibm.com/infocenter/lnxinfo/v3r0m0/index.jsp?topic=%2Fliaai%2Fsaptuning%2Fsaptuningadjust.htm

http://doc.opensuse.org/documentation/html/openSUSE/opensuse-tuning/cha.tuning.taskscheduler.html

http://www.ibm.com/developerworks/linux/library/l-cfs/

http://www.hotaboutlinux.com/2010/01/tuning-the-linux-kernels-completely-fair-scheduler/

Difference between NUMA and SMP

http://developer.amd.com/Pages/810200618.aspx

http://sqlskills.com/blogs/jonathan/post/Understanding-Non-Uniform-Memory-AccessArchitectures-%28NUMA%29.aspx

AMD's Hammer Architecture - Making Sense of it All

Integrated Memory Controller & North Bridge

http://www.anandtech.com/show/838/6

Notifier chain update: API changes

http://lwn.net/Articles/171560/

搞定一个kobjects, sysfs相关的问题

最近在把一个功能从“新”的2.6.38内核BACK PORT到2.6.9上面。碰到了很多稀奇古怪的问题。比如有的函数，在EXPORT_SYMBOL之后，可以被其他函数调用，但是返回的指针的高32位会被自动清零（目标是 X86/64BIT SMP). 搞了半天，发现一定要在.H里面声明一下才行。

今天搞的SYSFS的一个问题。在我把新代码复制到老的内核上面之后，发现少了一部分SYSFS文件，但是其他几个又在的。于是看了半天SYSFS, KOBJECT. 总算搞清楚了一点。

KOBJECTS可以指定一个KTYPES,在KTYPES里面包括有SYSFS_OP 和DEFAULT_ATTRS。如果这些都设置好了，在KOBJECT_ADD的时候，就会自动在 SYSFS下面生成相应的 SYSFS 文件。另外一个方法是调用sysfs_create_file. 这样可以添加新的文件。

在新的内核里面，KTYPES是在 调用KOBJECT_INIT 或者类似函数的时候，就要传过去的。然后在函数内部设置好。老的内核还是要自己设置。

需要注意的是，设置 KTYPES 一定要在调用 KOBJECT_ADD（或者类似函数）之前。否则设了也没用。我今天就是调试了半天才发现这点。

另外比较奇怪的是，开始我把ktypes设置放到了后面，然后跑了下，发现多了几个sysfs文件。于是让我误以为ktypes已经设置好了。后来才发现根本没放对地方。不过为啥放在后面也会多出几个sysfs文件呢？这个就搞不清楚了。先回家去再说。

A quicker way to get vmlinuz

Sometimes, I just want a linux kernel (such as for debugging). "make" command can get it, but it waste a lot of time because it also compiles all the modules which I don't need.

So I did some google search and find out "make bzImage" is the right command to use. After that, the kernel file is in arch/x86/boot/bzImage. bzImage is the same as vmlinuz .

btw: all these vmlinuz, bzImage names are very confusing. :(

4.25.2012 update: just change vmlinux to vmlinuz. The former is uncompressed and with all the symbols; it normally used for debugging. The latter is actually used for boot.

vi/vim cheatsheet

http://www.worldtimzone.com/res/vi.html

back porting native_rdmsr_safe_regs

This function is used by new Linux kernels and I need to port it back to an old 2.6.9 kernel. The compiler complains that cannot find the reference to this function and its brother ( native_wrmsr_safe_regs).

Then I used vim/cscope to search symbols/text for native_wrmsr_safe_regs, but cannot find anything about it. Google it gave the same result. After some time, I used gitk to check the log of a related c file and found out these two functions are defined in an assembly file, by using macros.

Then I happily copied that assembly file (msr-reg.S) to the old kernel source. But this time I got some weird errors as "invalid character '(' in mnemonic". Then I google for this for some time and noticed that there is some definitions in "link/linkage.h". For example, ENTRY used in the msr-reg.S is defined there.

Finally I found out "ENDPROC" used in msr-reg.S is not in my version of linkage.h. After copy that definition, the compiler does not complain about these functions again.

Fixed a problem of cscope_maps.vim

The introduction for cscope_maps.vim is here: http://cscope.sourceforge.net/cscope_vim_tutorial.html

It is a good plugin for VIM, but I could not use it on my machine somehow. After google search and tried some method to debug the plugin, the problem still exists.

Finally, I noticed that when I launch vim, there is an error message complaining about the line 42 of cscope_maps.vim. Maybe that error prevents the plugin to be loaded. So I just go ahead, open the cscope_maps.vim and comment out the line 42 and some related lines, then the plugin works! I can use all the shortcut keys to search the source code now. :)

Create a PDF With embedded fonts using Preview

On Mac OS X

http://hints.macworld.com/article.php?story=20060203175741232

Note: with above method, the fonts are embedded, but it will not pass IEEE conference paper pdf checks, because the pdf version is older than adobe 5.x. I tried many other methods but all of them cannot embedded all fonts due to some errors.

Finally, I use similar steps as the link to create a PS file instead a pdf file. Then convert this ps file with Adobe distiller on a Windows machine.

ctrl+s on Linux

http://raamdev.com/2007/recovering-from-ctrls-in-putty/

follow ctrl+s, press ctrl+q to recover when on a Linux console.

Per CPU data

http://www.kernel.org/pub/linux/kernel/people/rusty/kernel-locking/x536.html

http://lwn.net/Articles/22911/

LKD2

http://www.makelinux.net/books/lkd2/ch11lev1sec10 (and following pages)

SMP affinity and proper interrupt handling in Linux

http://www.alexonlinux.com/smp-affinity-and-proper-interrupt-handling-in-linux

How to trace Linux oops or panic

http://lxr.linux.no/linux+v3.2.6/Documentation/oops-tracing.txt

Note: vmlinx is different from vmlinuz. The former has a much bigger size.

cscope

http://cscope.sourceforge.net/cscope_vim_tutorial.html

cscope vs ctag
http://stackoverflow.com/questions/934233/cscope-or-ctags-why-choose-one-over-the-other

hwo to search
http://vim.wikia.com/wiki/Cscope

shortcuts in VIM:

http://thripal.blogspot.com/2009/10/cscope-with-vim.html

tab and spaces conversion in vim

http://vim.wikia.com/wiki/Converting_tabs_to_spaces

To manually change indent quickly, use "==", "<<", or ">>" .

bash guide

http://tldp.org/LDP/Bash-Beginners-Guide/html/index.html


advanced bash script.

tracing in Linux

Tracing: no shortage of options

http://lwn.net/Articles/291091/

Linux start-up process

http://www.cromwell-intl.com/unix/linux-boot.html
http://luv.asn.au/overheads/linux-startup.html
http://www.yolinux.com/TUTORIALS/LinuxTutorialInitProcess.html
http://www.comptechdoc.org/os/linux/startupman/linux_surcsysinit.html