Performance

一台正常运行的*nix机器，在满负荷运转的时候的load是1.0。

我们这里有4台机器，负载是1000。

经过近乎疯狂的整治，第一天将负荷降到了0.7，但第二天终于还是绷不住了，基本维持在100左右。中秋节发短信的人真多啊……

The RCng system was developed by NetBSD and FreeBSD have adopted it. _rc_subr_loaded is a flag that both system adopts to speed up the startup.

The FreeBSD approach is to determine whether to run for the whole rc.subr script, while NetBSD approach is to define it as a “:” so rc_subr won’t be loaded.

Which is better?

To quote his “I would recommend against per-thread caches. Instead, make the per-cpu caches actually *be* per-cpu (that is, not require a mutex).”

Then, he has pointed out that there is potential problems in FreeBSD’s SLAB allocator which is different from DragonFly’s. (Not too surprisingly, he is again advertising his IPI message approach).

激动人心的时刻即将来临。FreeBSD RELENG_5将于8月16日(自然，如果不出意外的情况下)建立。今天FreeBSD.org做了一个惊人的举动——将www.FreeBSD.org升级为5.x版本，这是Yahoo!以及FreeBSD.org对于RELENG_5的一项重大支持。

FreeBSD 5-STABLE的Release Engineering将是一个曲折而漫长的过程。这个过程的成败将直接影响接下来至少半年之内FreeBSD的命运。目前，FreeBSD 5-CURRENT在被命名为5-STABLE之前所需要经历的洗礼包括：

I have a preliminary discussion with junsu and we are still confused with the idlepoll livelock issue.

http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/kern/kern_poll.c

grep cgi-bin scripttime | cut -f6,8 -d’ ’ | sed -E s/\\\?.+//g | grep cgi-bin | sort | uniq -c | sort > statis

Where scripttime is a log with %T (script execution time) log. The above command line will obtain execution time, script name from log, then sort it by the execution time, then have a counted unique.

niklas has committed the final SMP branch code, no more SMP branchs, we have SMP in OpenBSD-CURRENT now!!

自从01年dillon commit之后一直就用着MAXUSERS 0。今天alu提到说MAXUSERS不合适的时候有可能会造成系统负荷能力下降，于是看了代码，发现MAXUSERS是根据内存大小算出来的，32-512之间。另外，实践证明MAXUSERS看来不能设置为2048(起不来)……

I don’t use Access for serious applications, and the biggest problem with it is performance concerns. It does not support concurrent accesses, and hence we will have a big trouble if our server is heavily loaded.

Dr. Alan Cox (alc@) has committed several improvements to FreeBSD’s VM implementation, and this brought significant performance gains on 5-CURRENT.