diff options
author | Yinghai Lu <yinghai@kernel.org> | 2008-12-05 21:58:31 -0500 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2008-12-08 08:31:51 -0500 |
commit | 0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac (patch) | |
tree | 239251bad791fd60af8c0f2ba365b7188395c83f /drivers/char/random.c | |
parent | 218d11a8b071b23b76c484fd5f72a4fe3306801e (diff) |
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 'drivers/char/random.c')
-rw-r--r-- | drivers/char/random.c | 22 |
1 files changed, 5 insertions, 17 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 675076f5fca8..d26891bfcd41 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c | |||
@@ -558,23 +558,9 @@ struct timer_rand_state { | |||
558 | unsigned dont_count_entropy:1; | 558 | unsigned dont_count_entropy:1; |
559 | }; | 559 | }; |
560 | 560 | ||
561 | static struct timer_rand_state *irq_timer_state[NR_IRQS]; | 561 | #ifndef CONFIG_SPARSE_IRQ |
562 | 562 | struct timer_rand_state *irq_timer_state[NR_IRQS]; | |
563 | static struct timer_rand_state *get_timer_rand_state(unsigned int irq) | 563 | #endif |
564 | { | ||
565 | if (irq >= nr_irqs) | ||
566 | return NULL; | ||
567 | |||
568 | return irq_timer_state[irq]; | ||
569 | } | ||
570 | |||
571 | static void set_timer_rand_state(unsigned int irq, struct timer_rand_state *state) | ||
572 | { | ||
573 | if (irq >= nr_irqs) | ||
574 | return; | ||
575 | |||
576 | irq_timer_state[irq] = state; | ||
577 | } | ||
578 | 564 | ||
579 | static struct timer_rand_state input_timer_state; | 565 | static struct timer_rand_state input_timer_state; |
580 | 566 | ||
@@ -933,8 +919,10 @@ void rand_initialize_irq(int irq) | |||
933 | { | 919 | { |
934 | struct timer_rand_state *state; | 920 | struct timer_rand_state *state; |
935 | 921 | ||
922 | #ifndef CONFIG_SPARSE_IRQ | ||
936 | if (irq >= nr_irqs) | 923 | if (irq >= nr_irqs) |
937 | return; | 924 | return; |
925 | #endif | ||
938 | 926 | ||
939 | state = get_timer_rand_state(irq); | 927 | state = get_timer_rand_state(irq); |
940 | 928 | ||