I noticed that 2.4.21-pre4 had the same problem whereas -ac1 and -aa1 worked
fine. But unfortunately, this was unrelated since both use irq_balance which
seems to work around or fix the problem. So I searched back the earlier
versions, and finally narrowed this problem down to the introduction of
CONFIG_X86_NUMA and associated code in 2.4.21pre1.
If I compile my kernel for an SMP K7, only CPU0 gets the interrupts. But if
I enable CONFIG_X86_CLUSTERED_APIC by enabling either CONFIG_X86_NUMAQ or
CONFIG_X86_SUMMIT (CONFIG_X86_NUMA alone isn't enough), then I get my interrupts
distributed across both CPUs. This is on an Asus A7M266D with 2 Athlon XP 1800+.
I don't know if this option can affect performance or stability.
BTW, the system runs in Flat APIC mode, as reported at boot time. I can provide
dmesg on request, but didn't want to pollute the list.
I looked through the code but since I don't know much about APIC, I didn't
understand the changes nor how they would affect what I observed.
Anyone has any clue ?
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to email@example.com
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/