Messages in this thread Patch in this message | | | Date | Mon, 05 Aug 2002 16:51:34 -0700 | From | "Martin J. Bligh" <> | Subject | [PATCH] NUMA-Q disable irqbalance |
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This patch is from Matt Dobson. It disables irq_balance for the NUMA-Q and makes it a config option for everyone else. This is needed for NUMA-Q to work, since the irq_balance code assumes a logical flat apic addressing mode that's not true in all cases. We created a config option since irq_balance makes performance significantly worse for some workloads.
Please apply,
Martin.
diff -Nur linux-2.5.25-vanilla/arch/i386/Config.help linux-2.5.25-patched/arch/i386/Config.help --- linux-2.5.25-vanilla/arch/i386/Config.help Fri Jul 5 16:42:04 2002 +++ linux-2.5.25-patched/arch/i386/Config.help Thu Jul 11 17:27:01 2002 @@ -41,6 +41,12 @@ 486, 586, Pentiums, and various instruction-set-compatible chips by AMD, Cyrix, and others. +CONFIG_IRQ_BALANCE + This option is used to turn IRQ Balancing on machines with multiple + APIC's (ie: SMP, NUMA, etc) on or off. This behavior has been seen + under some conditions to reduce performance, and on some platorms causes + interesting hangs, particularly those with more than 8 CPUs. + CONFIG_MULTIQUAD This option is used for getting Linux to run on a (IBM/Sequent) NUMA multiquad box. This changes the way that processors are bootstrapped, diff -Nur linux-2.5.25-vanilla/arch/i386/config.in linux-2.5.25-patched/arch/i386/config.in --- linux-2.5.25-vanilla/arch/i386/config.in Fri Jul 5 16:42:20 2002 +++ linux-2.5.25-patched/arch/i386/config.in Thu Jul 11 17:16:52 2002 @@ -164,8 +164,19 @@ if [ "$CONFIG_X86_UP_IOAPIC" = "y" ]; then define_bool CONFIG_X86_IO_APIC y fi + define_bool CONFIG_IRQBALANCE n else bool 'Multiquad NUMA system' CONFIG_MULTIQUAD + if [ "$CONFIG_MULTIQUAD" = "y" ]; then + define_bool CONFIG_IRQBALANCE_DISABLE y + else + bool 'Turn Off IRQ Balancing' CONFIG_IRQBALANCE_DISABLE + fi + if [ "$CONFIG_IRQBALANCE_DISABLE" = "y" ]; then + define_bool CONFIG_IRQBALANCE n + else + define_bool CONFIG_IRQBALANCE y + fi fi bool 'Machine Check Exception' CONFIG_X86_MCE diff -Nur linux-2.5.25-vanilla/arch/i386/kernel/io_apic.c linux-2.5.25-patched/arch/i386/kernel/io_apic.c --- linux-2.5.25-vanilla/arch/i386/kernel/io_apic.c Fri Jul 5 16:42:20 2002 +++ linux-2.5.25-patched/arch/i386/kernel/io_apic.c Thu Jul 11 16:12:28 2002 @@ -199,7 +199,7 @@ spin_unlock_irqrestore(&ioapic_lock, flags); } -#if CONFIG_SMP +#if CONFIG_IRQBALANCE typedef struct { unsigned int cpu; @@ -211,15 +211,12 @@ extern unsigned long irq_affinity [NR_IRQS]; -#endif - #define IDLE_ENOUGH(cpu,now) \ (idle_cpu(cpu) && ((now) - irq_stat[(cpu)].idle_timestamp > 1)) #define IRQ_ALLOWED(cpu,allowed_mask) \ ((1 << cpu) & (allowed_mask)) -#if CONFIG_SMP static unsigned long move(int curr_cpu, unsigned long allowed_mask, unsigned long now, int direction) { int search_idle = 1; @@ -264,9 +261,9 @@ set_ioapic_affinity(irq, 1 << entry->cpu); } } -#else /* !SMP */ +#else /* !CONFIG_IRQBALANCE */ static inline void balance_irq(int irq) { } -#endif +#endif /* CONFIG_IRQBALANCE */ /* * support for broken MP BIOSs, enables hand-redirection of PIRQ0-7 to - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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