delphij's Chaos

三类人

Life

别人总结的。

一类可以做朋友，这类人绝对不能有（在我看来是）人品问题的问题；
一类可以做生意，这类人也许有一些在我看来是人品问题的问题，但是他们有底限；
还有一类既不能做朋友，也不能做生意，因为这些人连底限都没有。

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DNS中的SRV记录

Distributed Computing

最近看代码时了解到的，顺手查了一下，在此留个记录：

SRV记录的作用是指明某域名下提供的服务。

例子：

_http._tcp.example.com. SRV 10 5 80. www.example.com

SRV后面项目的含义：

10 - 优先级，类似MX记录
5 - 权重
80 - 端口
www.example.com - 实际提供服务的主机名。

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说一个笑话，大家一乐

Life

起初，他们只是不支持FreeBSD/Linux，我有Windows远程桌面，我没投诉；
到后来，他们不允许Windows远程桌面，我可以本地访问一台64位的Windows 2003 Server，勉强投诉两句，暂时也忍了；
再后来，他们又写了不支持64位Windows 2003 Server的所谓「安全」驱动，我拼命投诉，可是他们不理我了，更有人说，我是「小众系统」，正如一开始人们说FreeBSD/Linux两种系统一样。

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ULE 2.0 hits -HEAD

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.

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Conclusion, 2006

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。

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嗔念

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。

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