Kpld's Blog

migrate blog to here and bakup

kpld8888 — Thu, 30 Sep 2010 06:24:22 +0000

http://kpld.blogspot.com
http://kpld.livejournal.com

Include path and link path environment variables

kpld8888 — Thu, 19 Aug 2010 23:38:26 +0000

C_INCLUDE_PATH
CPLUS_INCLUDE_PATH
LIBRARY_PATH
CPATH

deb package generation

kpld8888 — Wed, 18 Aug 2010 23:52:01 +0000

1. tar xvf _.tar.gz
2. cd _
3. dh_make ../_.tar.gz
4. modify file debian/control
5. dpkg-buildpackage,then generate ../__arch.deb

Hash

kpld8888 — Wed, 04 Aug 2010 01:58:24 +0000

// RS Hash Function

unsigned int RSHash(char *str)

{

unsigned int b = 378551;

unsigned int a = 63689;

unsigned int hash = 0;

while (*str)

{

hash = hash * a + (*str++);

a *= b;

}

return (hash & 0x7FFFFFFF);

}

// JS Hash Function

unsigned int JSHash(char *str)

{

unsigned int hash = 1315423911;

while (*str)

{

hash ^= ((hash << 5) + (*str++) + (hash >> 2));

}

return (hash & 0x7FFFFFFF);

}

// P. J. Weinberger Hash Function

unsigned int PJWHash(char *str)

{

unsigned int BitsInUnignedInt = (unsigned int)(sizeof(unsigned int) * 8);

unsigned int ThreeQuarters = (unsigned int)((BitsInUnignedInt * 3) / 4);

unsigned int OneEighth = (unsigned int)(BitsInUnignedInt / 8);

unsigned int HighBits = (unsigned int)(0xFFFFFFFF) << (BitsInUnignedInt – OneEighth);

unsigned int hash = 0;

unsigned int test = 0;

while (*str)

{

hash = (hash << OneEighth) + (*str++);

if ((test = hash & HighBits) != 0)

{

hash = ((hash ^ (test >> ThreeQuarters)) & (~HighBits));

}

return (hash & 0x7FFFFFFF);

}

// ELF Hash Function

unsigned int ELFHash(char *str)

{

unsigned int hash = 0;

unsigned int x = 0;

while (*str)

{

hash = (hash << 4) + (*str++);

if ((x = hash & 0xF0000000L) != 0)

{

hash ^= (x >> 24);

hash &= ~x;

}

return (hash & 0x7FFFFFFF);

}

// BKDR Hash Function

unsigned int BKDRHash(char *str)

{

unsigned int seed = 131; // 31 131 1313 13131 131313 etc..

unsigned int hash = 0;

while (*str)

{

hash = hash * seed + (*str++);

}

return (hash & 0x7FFFFFFF);

}

// SDBM Hash Function

unsigned int SDBMHash(char *str)

{

unsigned int hash = 0;

while (*str)

{

hash = (*str++) + (hash << 6) + (hash << 16) – hash;

}

return (hash & 0x7FFFFFFF);

}

// DJB Hash Function

unsigned int DJBHash(char *str)

{

unsigned int hash = 5381;

while (*str)

{

hash += (hash << 5) + (*str++);

}

return (hash & 0x7FFFFFFF);

}

// AP Hash Function

unsigned int APHash(char *str)

{

unsigned int hash = 0;

int i;

for (i=0; *str; i++)

{

if ((i & 1) == 0)

{

hash ^= ((hash << 7) ^ (*str++) ^ (hash >> 3));

}

else

{

hash ^= (~((hash << 11) ^ (*str++) ^ (hash >> 5)));

}

return (hash & 0x7FFFFFFF);

}

linux kernel crash analyze

kpld8888 — Wed, 28 Jul 2010 16:56:39 +0000

ksymoops -m System.map < oops.txt

debug linux kernel with Eclipse

kpld8888 — Sun, 25 Jul 2010 06:31:57 +0000

http://issaris.blogspot.com/2007/12/download-linux-kernel-sourcecode-from.html

Linux的I/O调度

kpld8888 — Thu, 08 Jul 2010 00:33:38 +0000

1. 电梯调度算法：io请求按块号排序放在一个普通队列。

2. Deadline算法：电梯调度算法，并增加了读FIFO队列与写FIFO队列。先按普通队列处理，若超时，再按FIFO队列进行处理。

3. Anticipatory算法：Deadline算法，并增加预测机制（6毫秒）。

4. CFQ（公平调度）算法：每个进程有自己的io请求队列，每个队列分配一个时间片。若超时，就处理下一个进程的队列。否则处理当前队列直至为空，之后空转10ms，看是否有新的请求。若无，则处理下一进程。此算法适合高负载的情况。

useful tools

kpld8888 — Sat, 19 Jun 2010 23:13:07 +0000

lxzrz: Communication package providing the X, Y, and ZMODEM file transfer protocols

http://www.ohse.de/uwe/software/lrzsz.html

kibitz: similar to multi-user mode of screen

http://expect.nist.gov/

http://nails.blog.51cto.com/640492/138028

dstat: Dstat is a versatile replacement for vmstat, iostat and ifstat

http://dag.wieers.com/home-made/dstat/

switch server under ssh

kpld8888 — Thu, 17 Jun 2010 18:12:12 +0000

input "~" and Ctrl+Z to go back
use fg to go to

android notes

kpld8888 — Fri, 11 Jun 2010 17:16:09 +0000

root shell: adb shell
upload file: adb remount
adb push c:111 /sdcard/
download file: adb pull /sdcard/xxx c:
install app: adb install [-s] xxx.apk # -s: to sdcard
uninstall app: adb uninstall [-k] xxx.apk # -k: keep data
get serialno: adb get-serialno