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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 /include/linux/irqnr.h | |
| parent | Fix a race condition in FASYNC handling (diff) | |
| download | linux-dev-0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac.tar.xz linux-dev-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 'include/linux/irqnr.h')
| -rw-r--r-- | include/linux/irqnr.h | 14 |
1 files changed, 3 insertions, 11 deletions
diff --git a/include/linux/irqnr.h b/include/linux/irqnr.h index 452c280c8115..7a299e989f8b 100644 --- a/include/linux/irqnr.h +++ b/include/linux/irqnr.h @@ -7,18 +7,10 @@ # define for_each_irq_desc(irq, desc) \ for (irq = 0; irq < nr_irqs; irq++) -#else -extern int nr_irqs; -# define for_each_irq_desc(irq, desc) \ - for (irq = 0, desc = irq_desc; irq < nr_irqs; irq++, desc++) - -# define for_each_irq_desc_reverse(irq, desc) \ - for (irq = nr_irqs - 1, desc = irq_desc + (nr_irqs - 1); \ - irq >= 0; irq--, desc--) +static inline early_sparse_irq_init(void) +{ +} #endif -#define for_each_irq_nr(irq) \ - for (irq = 0; irq < nr_irqs; irq++) - #endif |