I found a bug when using the Ethernet controller: Realtek Semiconductor Co.,
Ltd. RTL-8169 Gigabit Ethernet (rev 10) ethernet card and kernel High
Resolution Timers (menuconfig -> Processor type and features -> High
Resolution Timer Support )
after about 20 kernel compiles i finnaly figured out this option was making
the ethernet card slow
tested kernels 2.6.22,2.6.22.5, 2.6.23-rc4 (running now)
the cpu is the pc is a p3 667 mhz so its cpu limited i guess and maxes at
400mbit~. (without High Resolution Timers )
with High Resolution Timers off it would only do 50-70mbit.
r8169 (compile as module + napi)
High Resolution Timer Support (enabled)
tested with iperf also system is very unresponsive i cant even open a ssh
session or type a command while the test ran
[ 5] 0.0-10.0 sec 64.5 MBytes 54.0 Mbits/sec
r8169 (compile as module + napi)
High Resolution Timer Support (disabled)
[ 3] 0.0-10.0 sec 552 MBytes 463 Mbits/sec
as you can see with it disabled the speed really improved.
but im wondering what does High Resolution Timer's do and what does it have
to do with a pci gigabit ethernet card that would slow it down
maybe someone else could test and see if they get the same results
this might solve alot of problems with this card since alot of distros
compile Resolution Timer default to enabled...
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On Thu, 30 Aug 2007, n wrote:
> I found a bug when using the Ethernet controller: Realtek Semiconductor Co.,
> Ltd. RTL-8169 Gigabit Ethernet (rev 10) ethernet card and kernel High
> Resolution Timers (menuconfig -> Processor type and features -> High
> Resolution Timer Support )
> after about 20 kernel compiles i finnaly figured out this option was making
> the ethernet card slow
> tested kernels 2.6.22,2.6.22.5, 2.6.23-rc4 (running now)
>
> the cpu is the pc is a p3 667 mhz so its cpu limited i guess and maxes at
> 400mbit~. (without High Resolution Timers )
> with High Resolution Timers off it would only do 50-70mbit.
>
> r8169 (compile as module + napi)
> High Resolution Timer Support (enabled)
> tested with iperf also system is very unresponsive i cant even open a ssh
> session or type a command while the test ran
> [ 5] 0.0-10.0 sec 64.5 MBytes 54.0 Mbits/sec
>
> r8169 (compile as module + napi)
> High Resolution Timer Support (disabled)
> [ 3] 0.0-10.0 sec 552 MBytes 463 Mbits/sec
>
> as you can see with it disabled the speed really improved.
> but im wondering what does High Resolution Timer's do and what does it have to
> do with a pci gigabit ethernet card that would slow it down
> maybe someone else could test and see if they get the same results
>
> this might solve alot of problems with this card since alot of distros compile
> Resolution Timer default to enabled...