Bug 20555
| Summary: | 3C509 driver performance problem | ||
|---|---|---|---|
| Product: | Base System | Reporter: | xyf <xyf> |
| Component: | misc | Assignee: | freebsd-bugs (Nobody) <bugs> |
| Status: | Closed FIXED | ||
| Severity: | Affects Only Me | ||
| Priority: | Normal | ||
| Version: | Unspecified | ||
| Hardware: | Any | ||
| OS: | Any | ||
On Fri, Aug 11, 2000 at 06:46:39PM -0700, xyf@stocke.com wrote: > FreeBSD uses more CPU time than Linux, FreeBSD CPU idle is 40%, > Linux CPU idle is 60%, almost 20% CPU lost in FreeBSD! How do you know top(1) doesn't measure CPU idle time on Linux differently than it does on FreeBSD? (I don't know whether they do or not, for the record, but I do know things like load averages are measured differently..) Plus, with no real way to "fix" this "problem", this PR is rather bogus. If it is determined that the 3c509 driver sucks in terms of performance, patches to increase its efficiency and such are quite acceptable. :) Besides, no one in their right mind that worries about performance is going to use a 3c509... -- Will Andrews <andrewsw@purdue.edu> <will@FreeBSD.org> GCS/E/S @d- s+:+ a--- C++ UB++++$ P+ L- E--- W+ N-- !o ?K w--- O- M+ V- PS+ PE++ Y+ PGP+>+++ t++ 5 X+ R+ tv+ b++ DI+++ D+ G++ e>++++ h! r- y? On Fri, 11 Aug 2000 xyf@stocke.com wrote: > ab -c 10 -n 10000 http://192.168.1.27/index.html > > they both give me good performance, the result is almost same, but ... > FreeBSD uses more CPU time than Linux, FreeBSD CPU idle is 40%, > Linux CPU idle is 60%, almost 20% CPU lost in FreeBSD! > > I use "top" command and see FreeBSD cost 34% of CPU time in interrupt > handling, the system time is good, only 12%, my net card is old 3COM 3C509, my question is: > > is this the problem of 3C509 driver in FreeBSD or just is more serious FreeBSD design problem? I dodn't see any problem here, except missing accounting for interrupt time in Linux. I think Linux still counts interrupt time against whatever process (including the idle "process") happens to be running when the interrupt occurs. FreeBSD's idle time of 40% is actually the idle time (modulo jitter in the measurement). Linux's idle time of 60% may be mostly spent handling interrupts. Similarly for system and user times. System and user times under Linux are normally larger than under FreeBSD, because parts of them are actually interrupt times. Bruce State Changed From-To: open->closed Asked and answered. |
I just freshly installed Redhat Linux 6.2 and FreeBSD 4.0 on same machine, I run ApacheBench program ab on another Linux machine to test the both OS, both OS have same Apache config options, using command: ab -c 10 -n 10000 http://192.168.1.27/index.html they both give me good performance, the result is almost same, but ... FreeBSD uses more CPU time than Linux, FreeBSD CPU idle is 40%, Linux CPU idle is 60%, almost 20% CPU lost in FreeBSD! I use "top" command and see FreeBSD cost 34% of CPU time in interrupt handling, the system time is good, only 12%, my net card is old 3COM 3C509, my question is: is this the problem of 3C509 driver in FreeBSD or just is more serious FreeBSD design problem? Fix: don't kown How-To-Repeat: from another machine run apache benchmark program to pull FreeBSD, ab -c 10 -n 10000 http://192.168.1.27/index.html