willpower
- 浏览: 80793 次
-
最新评论
-
bailangfei3344：
自我介绍 -
regionwar：
你好，转化为人为：1、不该加锁的不要加锁:局部变量，单线程占用 ...
关于java锁机制的优化 -
danni505：
希望能交流：
msn:danni-505#hotmail.co ...
关于java锁机制的优化 -
ouspec：
收藏的东西不错。
TOP500 -
willpower：
The idea behind is e-sync IO do ...
Rethink the sync
文章列表
这10条里面最重要的一条:
Test, Test, Test!!!!!!!!!!!
原因很简单: 你都不知道哪里慢怎么提升性能?
原文请从此处下: http://www.cmg.org/conference/cmg2008/awards/
- 2009-07-07 15:47
- 浏览 837
- 评论(0)
This post describes our recent investigation into an interesting performance problem: benchmarks that we were surprised to find running significantly faster than we expected on new hardware. Along the way we discuss useful benchmarking tools, how to validate results, and why it pays to know exactly w ...
- 2009-04-16 10:34
- 浏览 802
- 评论(0)
Actual Performance, Perceived Performance
If you've used Windows Vista, you've probably noticed that Vista's file copy performance is noticeably worse than Windows XP. I know it's one of the first things I noticed. Here's the irony-- Vista's file copy is based on an improved algorithm and actually p ...
- 2009-02-05 11:34
- 浏览 1035
- 评论(0)
Mathematics for TopCoders
By dimkadimon
TopCoder Member
Introduction
I have seen a number of competitors complain that they are unfairly disadvantaged because many TopCoder problems are too mathematical. Personally, I love mathematics and thus I am biased in this issue. Nevertheless, I strongly be ...
- 2009-01-21 15:25
- 浏览 928
- 评论(0)
字符编码笔记：ASCII，Unicode和UTF-8
阮一峰 发表于 2007年10月28日 | 分类：首页 -> 档案 -> IT技术
今天中午，我突然想搞清楚Unicode和UTF-8之间的关系，于是就开始在网上查资料。
结果，这个问题比我想象的复杂，从午饭后一直看到晚上9点，才算初步搞清楚。
下面就是我的笔记，主要用来整理自己的思路。但是，我尽量试图写得通俗易懂，希望能对其他朋友有用。毕竟，字符编码是计算机技术的基石，想要熟练使用计算机，就必须懂得一点字符编码的知识。
1. ASCII码
我们知道，在计算机内部，所有的信息最终都表示为一个二进制的字符串。每一个 ...
- 2009-01-07 10:39
- 浏览 874
- 评论(0)
...
- 2008-11-28 14:59
- 浏览 634
- 评论(0)
必看的一本书
Computer Systems: A Programmer's Perspective
Google 一下吧, 这个是"必须的".
- 2008-11-14 14:41
- 浏览 811
- 评论(0)
TLB
Translation lookaside buffer
http://en.wikipedia.org/wiki/Translation_lookaside_buffer
- 2008-11-14 14:38
- 浏览 874
- 评论(0)
Spinlock
以下来自Wikipedia
Spinlock
From Wikipedia, the free encyclopedia
Jump to: navigation, search
In software engineering, a spinlock is a lock where the thread simply waits in a loop ("spins") repeatedly checking until the lock becomes available. As the thread remains active but isn't pe ...
- 2008-11-14 11:50
- 浏览 821
- 评论(0)
As a performance engineer, you must know "Context Switch"
If you don't know, I give three suggestions:
1> look up it in ur course books
2> back to school
3> Internet: http://en.wikipedia.org/wiki/Context_switch
- 2008-11-07 15:10
- 浏览 735
- 评论(0)
How to set up a simple LRU cache using LinkedHashMap
Caches
Caches are a simple way to improve the performance of an application that reads data from a "slow" source such as files on disk or rows of data from a database table, but may need to re-read the same data multiple times. The idea ...
- 2008-11-03 18:05
- 浏览 1230
- 评论(0)
很多developer会忽视，甚至是无视profile的重要性。总是想当然的做些性能优化。
经常有developer跑过来说：hey, 给我测测性能，我做了些优化。应该会有提升的。
ok, 没问题。我很愿意为你效劳。 但是经常碰到的结果是： 没有或只有很小的提升。
你告诉他，他还会认为你什么都不知道，你的测试结果不能说明问题。
我想也许是因为developer都认为自己知道的最多，喜欢想当然（只是也许）。
我这里想强调关于性能优化的一个前提：
你已经确定了某个地方是你系统的瓶颈所在。
怎么样确定？ 当然是profile了！！！
更好笑的是，我还常看到developer花了大力气把一个本 ...
- 2008-10-27 13:49
- 浏览 1080
- 评论(0)
非常有阅读价值的一篇论文!
Dynamo: Amazon’s Highly Available Key-value Store
http://www.allthingsdistributed.com/2007/10/amazons_dynamo.html
- 2008-10-22 17:20
- 浏览 990
- 评论(0)
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
public class HighContentionSimulator implements Runnable {
enum Mode implements Runnable {
LOCK {
private final Lock lock = new ReentrantLock();
public void run() {
...
- 2008-10-22 17:05
- 浏览 922
- 评论(0)
Clapton不插电(unplugged)里面的歌曲.
推荐里面的三首歌:
1> Signe
2> layla
3> tears in heaven
- 2008-10-21 18:07
- 浏览 991
- 评论(0)