f**e
发帖数: 1269 | 1 lick
v. licked, lick·ing, licks
v. tr.
To pass the tongue over or along: lick a stamp.
To lap up.
To lap or flicker at like a tongue: The waves licked the sides of the boat.
Slang. To punish with a beating; thrash.
Slang. To get the better of; defeat: licked her weight problem. |
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a*****c
发帖数: 3525 | 2 从这个词(Hokkien dialect)才知道这个牛妈妈是福建人。
http://online.wsj.com/article/SB1000142405274870411150457605971
* The Wall Street Journal
* THE SATURDAY ESSAY
* JANUARY 8, 2011
Why Chinese Mothers Are Superior
Can a regimen of no playdates, no TV, no computer games and hours of music
practice create happy kids? And what happens when they fight back?
By AMY CHUA
A lot of people wonder how Chinese parents raise such stereotypically
successful kids. They wonder what these parents do to produce so ma... 阅读全帖 |
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T********l
发帖数: 1670 | 3 Why Chinese Mothers Are Superior
THE SATURDAY ESSAY JANUARY 8, 2011
By AMY CHUA
A lot of people wonder how Chinese parents raise such stereotypically successful kids. They wonder what these parents do to produce so many math whizzes and music prodigies, what
it's like inside the family, andwhether they could do it too. Well, I can tell them, because I've done it. Here are some things my daughters, Sophia and Louisa, were never allowed to do:
• attend a sleepover
• have a playdate
&#... 阅读全帖 |
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t*****n
发帖数: 1589 | 4 你说的莽林中就是竹林深处吧，不知道哪个是通译，日人就是没有那种宏大深沉劲儿，
所以趋于扭曲变态就像鲁迅说的溃肿桃花
像日本的thrash metal和别国就不同，有点丧心病狂的意思，有个叫sabbat的black
metal band国际知名，也是扭曲变态多于西方的那种邪恶神秘恐怖
了却短促的一生 |
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b***s
发帖数: 14 | 5 in another word, graceful degradation in performance instead of
thrashing. |
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k*****y
发帖数: 744 | 6 http://www.brighthub.com/computing/windows-platform/articles/52
A hard fault happens when the address in memory of part of a program is no
longer in main memory, but has been instead swapped out to the paging file,
making the system go looking for it on the hard disk. When this happens a
lot, it causes slowdowns and increased hard disk activity. When it happens
an awful lot, the possibility of hard disk thrashing arises. That's when a
program stops responding, but the hard drive continues to run... 阅读全帖 |
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l*****o
发帖数: 473 | 7 我的一些看法：
有问题。
听楼主描述的现象是发生了page Thrashing.
IO bound的情况下，用多线程是非常有好处的。
在单CPU情况下，只有完全CPU bound的情况下，多线程是不利的。而且，多线程还可能
会引起false sharing，锁的开销等wanting。 |
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w****w
发帖数: 521 | 8 你这个慢主要是thrashing造成的，只要增加memory就行，上cluster没多大用。 |
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r****o
发帖数: 1950 | 9 前天onsite的一个题目，没答好。没什么思路。
请大侠们多指点。 |
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l******e
发帖数: 12192 | 10 哪个方面的？
如果是内存的，就几个函数交替的占用大内存，就行了。 |
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r****o
发帖数: 1950 | 13 非常感谢。我还想问一下，如果loop的话，一个函数退出，它分配的local内存就释放
了吧。 你是说用malloc()分配内存吗？ |
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r****o
发帖数: 1950 | 15 非常感谢。你是说malloc之后不free吗？
但是这样的话，后面的函数再malloc大内存会不会就返回失败了? |
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l******e
发帖数: 12192 | 16 可以先malloc好，每个函数用
比如
char * pa = (char *) malloc(1024*1024*124);
char * pb = (char *) malloc(1024*1024*124);
while(1)
{
fa(pa);
fb(pb);
} |
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r****o
发帖数: 1950 | 17 多谢。是不是malloc分配是否成功取决于虚拟内存的大小，而不是物理内存的大小? |
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p***o
发帖数: 1252 | 18 Probably thrashing will kill many graph algorithms ... |
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t****t
发帖数: 6806 | 19 atomic operation的瓶颈主要在内存控制器和各CPU之间对cache的thrashing, 并不是
毫无代价的. 不过确实比数据库实现要快很多了.
但是记录不好搞, 一旦垮了就全完蛋. |
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k**********g
发帖数: 989 | 20
Ideally, these frameworks should have supported two important models:
(1) dataflow model (similar to FRP, functional reactive programming, but
without the "leaky abstractions"), and
(2) Task dependency DAG model
Microsoft PPL (parallel patterns library) supports #1 out of the box.
I implemented the second model twice, in 2012 (without PPL) and 2013 (on top
of PPL). Relying on PPL simplifies the management of the thread pool,
especially for its initialization, automacially spinning up new thread... 阅读全帖 |
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m********2
发帖数: 89 | 21 "200多m的dic" 是只200 million k-v entries ? 才用1.45g内存 ？ 不可能吧？ 平均
一个k-v entry才不到 8 bytes ?
在我的x230, 16GB mem 上跑 200 million entries dict 会 page reclaim thrashing.
跑 100 million entries 的 dict 没问题:
# t.py
def t(n):
d = { i:i for i in range(n) }
print( hex(d[n-1]) )
python3 -m timeit -n 2 -r 1 -s 'import t' 't.t(100*2**20)'
2 loops, best of 1: 10.7 sec per loop
今天有点但疼：） |
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C**********r
发帖数: 8189 | 22
thrashing.
他可能有很多function套function，俺不知。俺觉得其实还是得会用的人来喷下比较有
说服力。
Java 8据说偷了好多functional的语法。 |
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w***g
发帖数: 5958 | 23 简单做做算术就知道。Lock是实现预防，overhead是L，每次运算都需要，所以概率为1.
总的来说overhead为L. L随着concurrency的增加非常慢，可以认为是
常数。对于单个lock来说，系统吞吐量基本上就是硬件所能支持的上限U减去overhead
： U - L。硬件用足后即使再增加线程，吞吐量基本上不会有太大的下降。
STM是事后补救，overhead是S. S和具体需要rollback和重算的内容有关。
STM失败的概率p随着concurrency的增加而增加. 平均下来每次成功
以前需要重试的次数为p/(1-p)，开销为 S*p/(1-p)。这个概率随着p->1会无限增大。
所以STM在线程数增加到一定程度会出现类似硬盘thrashing的情况，系统吞吐量最终会
下降到0。现在的CPU的线程数还没那么多，所以这点还没体现出来。
STM还有一个实际问题就是transaction比较大，并且线程数>>物理线程数的时候
会出问题。如果一个transaction还没完就因为时间片用完被切换下来，那么
这个transation成功的概率就会极大地减少。这个可以通过OS... 阅读全帖 |
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h***z
发帖数: 233 | 24 A few things to try:
1. Compiler options: Turn on compiler optimization as well as any SIMD
2. Libraries: Link against pre-compiled libraries tuned for your computer
architecture and tune parameters of any libraries that you compile yourself.
3. Your code: Keep in mind the cache size of your CPU and write your code to
avoid cache thrashing. |
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L*****k
发帖数: 13042 | 25 slayer是thrash的老大了，风格还是不完全一样。
megadeth出身重金属，更传统些。 |
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h*d
发帖数: 19309 | 26 http://www.vh1.com/news/222970/hard-rock-new-bands/
I often talk about the connections between metal and rock music. As far as I
am concerned, metal is just rock’s pissed off younger brother. As a
budding teenager discovering heavy music, my gateway was hard rock with a
metallic slant like Guns N Roses and Alice In Chains, or thrash metal bands
that were going through a rock-ish faze in the ’90s like Megadeth and
Metallica. The lines were very blurred from a categorization standpoint.
Before I b... 阅读全帖 |
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p******s
发帖数: 938 | 29 oh..rock and roll originates from Blues and Jazz,
and guitar is the most important instrument.
The bass plays the Root Note of the chord, and the rhythm guitar
plays the chord. It's pretty hard for beginner to distinguish
the bass from all the instruments, cos it's so low...
Rock is such a big genre and hard to tell what's the most famous..
Fade to Black is written by Metalica, the best band playing
Thrash Metal, a sub-genre of Heavy Metal,(I like them so much, :))
I can tell you some good band |
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