*Nix and Win32 Kernel
MUTEX_PROFILING拓展为LOCK_PROFILING了
对于MP内核来说,这是一项用于寻找内核中存在的性能弱点的重要工具。早先kris做的性能评估看来可以继续、常规化地做下去了。
参与评论if_ioctl的锁问题?
今天尝试了一下触发zonelim的方法,不过zonelim没搞出来,却发现了另一个问题——如果并发执行ifconfig配置同一块网卡,似乎有由于欠锁导致的断言失败。打算找时间研究一下。
参与评论KSE成为内核选项
今天,John Birrell同学commit了一个不大不小的patchset—-将KSE变为内核选项。具体说来,在-CURRENT上,KSE不再是一个必选项了。
KSE是FreeBSD 5.0-CURRENT时的一个非常重要的技术探索,它是对由华盛顿大学THOMAS E. ANDERSON等人提出的调度器激活概念的一个实现。
对于M:N线程来说,调度器激活是一项十分先进的概念。在这个模型中,内核并不需要了解用户态线程的细节,而用户态线程也并不是由内核直接调度,相反,这些线程被绑定到一系列"调度实体"上,内核能够看到这些调度实体,并在上下文切换时激活用户态的线程调度器。由于减少了内核-用户态的上下文切换操作,因此理论上这一模型能够获得更好的性能。
阅读全文…Andre's optimization to the FreeBSD socket send path
For those who does not track FreeBSD-CURRENT -current@, Andre Opperamann (andre@) has just posted a new progress for his TCP/IP optimization:
阅读全文…ULE returned to its "experimental" state
An internal discussion happened in -developers@ has finally decided that we put ULE scheduler back to the “experimental” state, in order to reduce the number of reports about crashes and other bad things for it.
Currently the fact that ULE is not being actively maintained is the cause of this change. We hope that we can find someone who has interest on it. Additionally, it is worthy to have a look at David Xu’s new “CORE” scheduler (a ULE fork, using Linux’s algorithm).
阅读全文…阿里夫·阿卜杜拉同学commit了Intel HDA驱动
总算支持了……这款声卡见于Dell Latitude D620/D820机型。
参与评论Awesome work, Matt!
To quote Matthew Dillon:
阅读全文…While I hope to avoid any destabilization, I am fiddling with some pretty hairy code in the VM system so this is a head’s up! I have successfully implemented a basic
MAP_VPAGETABLE
feature that allows a mmap()’d section of memory to be governed by a virtual page table. Basically the backing store for the mmap()’d space is the ‘physical memory’ used to map the space, and the mapping of the space is then governed by a ‘page table’ stored in that physical memory. (It is only physical memory from the point of view of the virtual kernel, not the real kernel of course). The mapping will store a physical page directory offset to tell the VM system where the page table is.
gdb helper for FreeBSD kernel
It seems that John Baldwin has published a debugging helper script for gdb, which is interesting to have a look at:
http://people.freebsd.org/~jhb/gdb.6
Maybe we can extend it to have some VM inspection function as well? :-)
参与评论不理解为什么从外界无法探测我的uptime
用的linksys的交换机,似乎没有启用任何防火墙功能。从网络流量上看,也没有很明显的规格化迹象。公司的Cisco交换机就没事,而且同网段的其他机器也没事,不理解。。。改天tcpdump一下。
参与评论CORE调度器
今天 David Xu commit了他的新调度器(SCHED_CORE),这个调度器基于ULE调度器,但改变了一系列算法。打算抽时间好好看一看代码。
参与评论