Prefmem of bus 3

Yinghai Lu yhlu at
Thu Mar 4 22:56:50 CET 2004


I have verified the myerinet card with s2882 in LinuxBIOS. It works well.


I wonder if round function in pci_device.c cause the bus prefmem region
calculation problem.

Also according to suggestion from quadrics and amd, it seems that BIOS and
kernel need to be patched to allow the prefmem region ( after mmio_basek) to
be put the mtrr as write-back to get the better perfmormance. i.e. 2.5us->1.
8us 0-byte ping pong. So may need to change the write_linuxbios_table and
update the struct mem_reagion.

I have attached the boot log with QM card. 
Also found the display mmio region of 0:18:1 is shown ad 0:18.0, but the
real reg content is right. But the prefmem region register of 1:2:0 is not
the same as 0xe0000000 to 0xffffffff, and it (0x24) is "01 e0 f1 ff"

Can some one send me the boot log of quadrics on other K8 board?



发件人: YhLu 
发送时间: 2004年3月1日 13:15
收件人: ebiederman at; ron minnich
抄送: LinuxBIOS
主题: 答复: Prefmem of bus 3

Some time you said that arima board connect all PCI-X slots of amd 8131 irq
to amd 8111 ioapic intead of 8131.

So even disable ioapic of 8131, device on PCI-X still works properly.

After enable ioapic of 8131, devices that are not using prefmem works well.


发件人: ebiederman at [mailto:ebiederman at] 
发送时间: 2004年3月1日 10:48
收件人: ron minnich
抄送: YhLu; ebiederman at; LinuxBIOS
主题: Re: Prefmem of bus 3

ron minnich <rminnich at> writes:

> On Fri, 27 Feb 2004, YhLu wrote:
> > Have you ever tested myrinet card on K8 MB under LinuxBIOS?
> we have a 1408-node K8 machine with myrinet working under linuxbios, and a

> 256-node K8 machine working with linuxbios. Arima HDAMA mainboards.
> I wonder what's going on here, I have not had time to look in detail.

So the problem appears to be that the prefmem region on the upper bus
is to large.

I wonder if why this work on LANL clusters and not on others is the
result of code skew.

Lightning nodes with myrinet only seem to have one prefmem region.

Yet another reminder that I really need to finish syncing up the code bases.

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