I have hacked a kernel and created a module that invokes some functions from this kernel. The mods work perfectly on my workstation, but I'm having several problems on a 64bit server which runs the exactly same Linux distribution.
The distro is a Ubuntu 7.04 and the kernel is 18.104.22.168-ubuntu1.
The only difference is that my workstation is i686 and the server is x86_64.
I am trying to write a MAC driver for Arm 11 MPcore in 2.6.23. The DMA'ble memory required is supposed to be non-cached for performance reasons.
A chunk of memory(~ 6MB) is allocated at startup using bigphys area patch. This physical area in the RAM is mmap'd to userspace as follows and thereafter carved into network buffers:
fd = open("/dev/mem", O_RDWR|O_SYNC);
I have a system that consists of 14 processoes .Under high load one processor shows 100% usage and rest show normal behaviour.Driver is NAPI compliant.So is it a driver issue or scheduler issue?. Kernel is 2.6. The output of "top" commands show that the cpu that is 100% consumed is running ksoftirqd and it is 0% idle and 100% SI.
Interrupts are evenly distributed over the system
I am using Debian Lenny with 2.6.30 kernel on my Intel Atom Poulsbo chipset computer and I get the following messages in my dmesg when I start the X server:
[ 22.760737] mtrr: type mismatch for 3ffc0000,10000 old: write-back new: write-combining
[ 22.760805] mtrr: type mismatch for 3ff80000,40000 old: write-back new: write-combining