x86 JUMP Reference

Instruction	Description	signed-ness	Flags	short jump opcodes	near jump opcodes
JO	Jump if overflow		OF = 1	70	0F 80
JNO	Jump if not overflow		OF = 0	71	0F 81
JS	Jump if sign		SF = 1	78	0F 88
JNS	Jump if not sign		SF = 0	79	0F 89
JE JZ	Jump if equal Jump if zero		ZF = 1	74	0F 84
JNE JNZ	Jump if not equal Jump if not zero		ZF = 0	75	0F 85
JB JNAE JC	Jump if below Jump if not above or equal Jump if carry	unsigned	CF = 1	72	0F 82
JNB JAE JNC	Jump if not below Jump if above or equal Jump if not carry	unsigned	CF = 0	73	0F 83
JBE JNA	Jump if below or equal Jump if not above	unsigned	CF = 1 or ZF = 1	76	0F 86
JA JNBE	Jump if above Jump if not below or equal	unsigned	CF = 0 and ZF = 0	77	0F 87
JL JNGE	Jump if less Jump if not greater or equal	signed	SF <> OF	7C	0F 8C
JGE JNL	Jump if greater or equal Jump if not less	signed	SF = OF	7D	0F 8D
JLE JNG	Jump if less or equal Jump if not greater	signed	ZF = 1 or SF <> OF	7E	0F 8E
JG JNLE	Jump if greater Jump if not less or equal	signed	ZF = 0 and SF = OF	7F	0F 8F
JP JPE	Jump if parity Jump if parity even		PF = 1	7A	0F 8A
JNP JPO	Jump if not parity Jump if parity odd		PF = 0	7B	0F 8B
JCXZ JECXZ	Jump if %CX register is 0 Jump if %ECX register is 0		%CX = 0 %ECX = 0	E3

Processor Flags

The x86 processors have a large set of flags that represent the state of the processor, and the conditional jump instructions can key off of them in combination.

CF - carry flag

Set on high-order bit carry or borrow; cleared otherwise

PF - parity flag

Set if low-order eight bits of result contain an even number of "1" bits; cleared otherwise

ZF - zero flags

Set if result is zero; cleared otherwise

SF - sign flag

Set equal to high-order bit of result (0 if positive 1 if negative)

OF - overflow flag

Set if result is too large a positive number or too small a negative number (excluding sign bit) to fit in destination operand; cleared otherwise

Reference: http://www.unixwiz.net/techtips/x86-jumps.html

RAID vs Erasure Coding

http://www.networkcomputing.com/storage/raid-vs-erasure-coding/1792588127

File System Comparison

https://zh.wikipedia.org/wiki/%E6%96%87%E4%BB%B6%E7%B3%BB%E7%BB%9F%E7%9A%84%E5%AF%B9%E6%AF%94

RAID Penalty

Each disk provide a certain amount of IO based off of the

• Rotational Speed
• Average Latency
• Average Seek Time(*)

Read Operation: NO Penalty

Write Operation:

RAID    Write Penalty

0            1(NO Penalty)

1            2

5            4(2R, 2W)

6            6(3R, 3W)

10          2

Reference: http://theithollow.com/2012/03/21/understanding-raid-penalty/

A Twist of the Wrist

1. 在彎中找到一個點，開啟油門，這個點可以在apex 之前。
2. 維持穩定的開啟狀態，提供0.1~0.2G的加速度，增加後輪的正向力，以符合前、後輪胎能提供的抓地力比例。
3. 當車身快到直立時，開啟的幅度可以大量增加，出彎加速，甚至在某個點，可以跳至全開。

註解：

1. 在彎中找到一個點開啟油門之後，避免再度關閉油門，就算打滑，也不能突然關油門。
2. 如果開啟油門後卻又發現必須關閉油門(run wide)，表示太早開啟油門了。
3. 在彎中到出彎，究竟在何時讓車身直立，油門可以開啟多少，這是個人修練了，也是賽道中的決勝點，但通常反應在下一個彎道入彎時。

Use nvm to manage node.js

1.   Use homebrew install nvm
    $ brew install nvm
    $ brew --prefix nvm
    $ echo ___/nvm.sh ~/.bash_profile
    $ . ~/.bash_profile
2.   Use nvm to install node.js
    $ nvm ls-remote
    $ nvm install v4.2.4
    $ nvm use v4.2.4
    $ nvm alias default v4.2.4





http://icarus4.logdown.com/posts/175092-nodejs-installation-guide

Color Setting

R: 219
G: 238
B: 221

light: 215