ULE 2.0 hits -HEAD

2007-01-05 01:38 | Kernel

Today, Jeff Roberson has committed his version 2.0 ULE scheduler. This new version has addressed several design issues as well as several bugs.

The new scheduler has adopted a circular queue, instead of the double-queue structure which is also found in the Linux O(1) scheduler. The latter has lead to difficulty implementing nice correctly.

For uniprocessor case, ULE is now faster.

MP algorithm has been simplified a bit.

A lot of bugfixes, etc.

To quote the original commit message:

ULE 2.0:

Remove the double queue mechanism for timeshare threads. It was slow due to excess cache lines in play, caused suboptimal scheduling behavior with niced and other non-interactive processes, complicated priority lending, etc.
Use a circular queue with a floating starting index for timeshare threads. Enforces fairness by moving the insertion point closer to threads with worse priorities over time.
Give interactive timeshare threads real-time user-space priorities and place them on the realtime/ithd queue.
Select non-interactive timeshare thread priorities based on their cpu utilization over the last 10 seconds combined with the nice value. This gives us more sane priorities and behavior in a loaded system as compared to the old method of using the interactivity score. The interactive score quickly hit a ceiling if threads were non-interactive and penalized new hog threads.
Use one slice size for all threads. The slice is not currently dynamically set to adjust scheduling behavior of different threads.
Add some new sysctls for scheduling parameters.

Bug fixes/Clean up:

Fix zeroing of td_sched after initialization in sched_fork_thread() caused by recent ksegrp removal.
Fix KSE interactivity issues related to frequent forking and exiting of kse threads. We simply disable the penalty for thread creation and exit for kse threads.
Cleanup the cpu estimator by using tickincr here as well. Keep ticks and ltick/ftick in the same frequency. Previously ticks were stathz and others were hz.
Lots of new and updated comments.
Many many others.

Tested on: up x86/amd64, 8way amd64.

阅读全文…( 本文约 506 字，阅读大致需要 3 分钟 )

Conclusion, 2006

2007-01-01 07:00 | Life

一直想找个时间总结一下。虽然本命年还没有结束，但是今天是2006年的最后一天，所以，确实是时候总结了。

阅读全文…( 本文约 542 字，阅读大致需要 2 分钟 )

嗔念

2006-12-31 06:11 | Life

昨天戴大师语重心长地说，施主嗔念太重。

想想确实是。从最近招商银行的事、工作的事、学习的事，以及一些人提出的非分要求，加上让人心烦意乱的各种各样的事情，家人的一些不理解等等，时时有什么时候绷不住劲，恶狠狠地爆发一下的冲动。但正如另一位大师说的，爆发这种事情，尽量避免出现，因为首先成本比较高，其次未必有作用，更则伤人害己。

参与评论

给tarsier上了RC2

2006-12-30 10:35 | Kernel

附加了一系列自己的patch，reboot。

[delphij@tarsier] ~> uname -a
FreeBSD tarsier.delphij.net 6.2-RC2 FreeBSD 6.2-RC2 #0: Sat Dec 30 01:18:20 CST 2006 delphij@tarsier.delphij.net:/usr/obj/usr/src/sys/TARSIER i386

参与评论

神啊！！(zz 水木社区)

2006-12-28 06:55 | Shared Chaos

强文一篇，吓坏了我了……立此存照，再orz一下这位。

发信人: triple7 (777), 信区: ITExpress
标题: 为什么中国出国上网的光缆都要通过美国？
发信站: 水木社区 (Wed Dec 27 13:47:37 2006), 站内

美国在这种小事上也要卡我们的脖子，非要我们通过他们才能访问国外网。我们在信息技术上如此受制于人吗？那一旦台海开战，中国怎么应对？

阅读全文…( 本文约 323 字，阅读大致需要 1 分钟 )

受台湾地震影响，境外网站访问出现问题

2006-12-27 18:57 | Distributed Computing

据新浪科技报道，受强烈地震影响，中美海缆、亚太1号、亚太2号海缆、FLAG海缆、亚欧海缆、FNAL海缆等多条国际海底通信光缆发生中断，中断点在台湾以南15公里的海域，造成附近国家和地区的国际和地区性通信受到严重影响。

参与评论

新的一年里改变你生活的50种方式zz

2006-12-27 01:35 | Shared Chaos

摘自 TechWeb。

2007年就要到来了，在新的一年里，如果有一种全新的生活方式你可以去尝试的话，你会不会说「我愿意」？如果你想在新的一年里获得健康、财富、幸福和快乐的话，你知道怎么去做吗？在这个高度发展的信息化时代，我们每个人都有机会成为天才，我们每个人的生活都将在未来的每一天发生巨大的变化——只要你愿意。最新一期《美国新闻与世界报道》的封面文章《改变你生活的50种方式》，告诉你如何在2007年完成「七十二变」。

阅读全文…( 本文约 2607 字，阅读大致需要 6 分钟 )