Re: 2.6.1 and irq balancing

[Martin J. Bligh]

> How much is significant? The term doesn't really help much. I will say that with one NIC taking 120MB/sec of data to a TB database and copying to two other machine (~220MB)  my interrupts got up in in the 5k-12k range with essentially CPU0 doing the work, some few percent going to CPU2.


1010 per second, IIRC. Try this patch:

diff -aurpN -X /home/fletch/.diff.exclude 290-gfp_node_strict/arch/i386/kernel/io_apic.c 310-irqbal_fast/arch/i386/kernel/io_apic.c
--- 290-gfp_node_strict/arch/i386/kernel/io_apic.c	Fri Jan  9 22:25:48 2004
+++ 310-irqbal_fast/arch/i386/kernel/io_apic.c	Fri Jan  9 22:27:55 2004
@@ -401,7 +401,7 @@ static void do_irq_balance(void)
 	unsigned long max_cpu_irq = 0, min_cpu_irq = (~0);
 	unsigned long move_this_load = 0;
 	int max_loaded = 0, min_loaded = 0;
-	unsigned long useful_load_threshold = balanced_irq_interval + 10;
+	unsigned long useful_load_threshold = balanced_irq_interval / 10;
 	int selected_irq;
 	int tmp_loaded, first_attempt = 1;
 	unsigned long tmp_cpu_irq;

M.

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