Some apps that use of frequent queries of the system time for example
MySQL are well known in FreeBSD to be slower then Linux because its
more expensive to call compared to Linux, maybe Tomcat is also another
such app this can also be double the case depending on on your jsp and
servlet code.
If you are on good hardware, are using 6 and keep your systems time
updated via ntp you might want to try changing from
kern.timecounter.hardware: ACPI-fast to TSC(-100) and doing a benchmark
this has already proven to increase performance of MySQL by a
significantly amount.
Also some new experimental low-precision time code has been added to
current source tree to see how much performance increases can be gained,
weirdly enough some people have argued against it for I guess a wide
range of reasons such as they just have crap hardware and don't care
about performance, don't like the extra maintenance of code or just like
Red Hat fanatics having an easy way to bad mouth FreeBSD performance. I
think most people would agree though that it has to be done, or have to
choose to believe FreeBSD isn't about performance among other goals.
With 6 you can also use the new thr threading library, try your
libmap.conf to libthr for testing, for example
[/usr/local/jdk1.4.2/]
libpthread.so.2 libthr.so.2
libpthread.so libthr.so
I been doing some 'ab' testing libthr with Apache2 compiled for worker
MPM and have some really interesting differences on server load, loads
of about 40 for pthread and around 5 thr under certain tests with ab
with the exact same test.
Mike
Eirik Øverby wrote:
Update: The diff below was made after making sure both systems are
running the exact same kernel. Behavior is the same. Building new
kernels (6-STABLE) now to get out of the BETA stage.
/Eirik
On Nov 28, 2005, at 22:53 , Eirik Øverby wrote:
Firmware versions are equal. BIOS settings are equal.
However, a diff of the dmesgs show (apart from MAC address
differences):
30c30
< Timecounter "ACPI-safe" frequency 3579545 Hz quality 1000
---
> Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000
What on earth is that all about? The "slow" box has the ACPI-fast
timecounter...
/Eirik
On Nov 28, 2005, at 22:14 , Kris Kennaway wrote:
On Mon, Nov 28, 2005 at 09:54:30PM +0100, Eirik ?verby wrote:
Hi,
I think I have found the culprit. There must be some sort of
difference between the machines after all (BIOS revision?), because
while on one machine the interrupt rate for the bge card stays very
low (2 to be exact) during maximum load, the other machine goes
beyond 1000 and keeps rising constantly. This might also explain why
performance slowly degrades over time on that machine, and response
times vary wildly, while the "fast" machine responds nicely within
1-2 seconds no matter the load and testing time.
I will have to investigate this more closely. Is there a way to force
the NIC to polling mode (I'm assuming that is the difference, an IRQ
rate of 2 is too low for a heavily loaded server if the NIC is
interrupt-driven)?
Anything else I could look at?
BIOS update.
Kris
_______________________________________________
freebsd-stable@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "[EMAIL PROTECTED]"
