Re: bug (trouble?) report on high mem support

John Helms
2002-03-15T20:29:25Z

Alan,

Ok, how do I go about determining that? The machine
I have is a brand-spankin' new IBM x-series 350 with
4 900MHz Xeon processors. The system bios can
recognize all of the 16320MB of memory at startup.
If those patches work, it will save our butts as
we have a major conversion project that hinges on
this.

Thanks,
jwh

>>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<<

On 3/15/02, 2:30:22 PM, Alan Cox <alan@lxorguk.ukuu.org.uk> wrote regarding
Re: bug (trouble?) report on high mem support:

> > Here is a top output. We have 16Gb of ram.
> > I have also tried a 2.4.9-31 enterprise=20
> > kernel rpm from RedHat with the same=20
> > results.

> Ok that would make sense. Next question is do you have an I/O controller
> that can use all the 64bit address space on the PCI bus ?

> What is happening is that you are using a lot of CPU copying buffers down
> into lower memory to transfer to/from disk - as well probably as that
> causing a lot of competition for low memory. If your I/O controller can
hit
> the full 64bit space there are some rather nice test patches that should
> completely obliterate the problem.

> Alan