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| author | Yinghai Lu <yinghai@kernel.org> | 2008-12-05 18:58:31 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-12-08 14:31:51 +0100 |
| commit | 0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac (patch) | |
| tree | 239251bad791fd60af8c0f2ba365b7188395c83f /arch/x86/kernel/irq.c | |
| parent | 218d11a8b071b23b76c484fd5f72a4fe3306801e (diff) | |
| download | blackbird-op-linux-0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac.tar.gz blackbird-op-linux-0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac.zip | |
sparse irq_desc[] array: core kernel and x86 changes
Impact: new feature
Problem on distro kernels: irq_desc[NR_IRQS] takes megabytes of RAM with
NR_CPUS set to large values. The goal is to be able to scale up to much
larger NR_IRQS value without impacting the (important) common case.
To solve this, we generalize irq_desc[NR_IRQS] to an (optional) array of
irq_desc pointers.
When CONFIG_SPARSE_IRQ=y is used, we use kzalloc_node to get irq_desc,
this also makes the IRQ descriptors NUMA-local (to the site that calls
request_irq()).
This gets rid of the irq_cfg[] static array on x86 as well: irq_cfg now
uses desc->chip_data for x86 to store irq_cfg.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/irq.c')
| -rw-r--r-- | arch/x86/kernel/irq.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index d1d4dc52f649..3f1d9d18df67 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -118,6 +118,9 @@ int show_interrupts(struct seq_file *p, void *v) } desc = irq_to_desc(i); + if (!desc) + return 0; + spin_lock_irqsave(&desc->lock, flags); #ifndef CONFIG_SMP any_count = kstat_irqs(i); |
