Messages in this thread Patch in this message | | | Date | Sun, 11 Jan 2009 09:48:00 -0800 | From | Mike Travis <> | Subject | Re: [PATCH 4/4] kstat: modify kstat_irqs_legacy to be variable sized |
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Mike Travis wrote: > Yinghai Lu wrote: >> On Sat, Jan 10, 2009 at 2:38 PM, Mike Travis <travis@sgi.com> wrote: >>> Impact: reduce memory usage. >>> >>> Allocate kstat_irqs_legacy based on nr_cpu_ids to deal with this >>> memory usage bump when NR_CPUS bumped from 128 to 4096: >>> >>> 8192 +253952 262144 +3100% kstat_irqs_legacy(.bss) >>> >>> This is only when CONFIG_SPARSE_IRQS=y. >>> >>> Signed-off-by: Mike Travis <travis@sgi.com> >>> --- >>> kernel/irq/handle.c | 9 ++++++--- >>> 1 file changed, 6 insertions(+), 3 deletions(-) >>> >>> --- linux-2.6-for-ingo.orig/kernel/irq/handle.c >>> +++ linux-2.6-for-ingo/kernel/irq/handle.c >>> @@ -124,8 +124,7 @@ static struct irq_desc irq_desc_legacy[N >>> } >>> }; >>> >>> -/* FIXME: use bootmem alloc ...*/ >>> -static unsigned int kstat_irqs_legacy[NR_IRQS_LEGACY][NR_CPUS]; >>> +static unsigned int *kstat_irqs_legacy; >>> >>> int __init early_irq_init(void) >>> { >>> @@ -146,9 +145,13 @@ int __init early_irq_init(void) >>> /* allocate irq_desc_ptrs array based on nr_irqs */ >>> irq_desc_ptrs = alloc_bootmem(nr_irqs * sizeof(void *)); >>> >>> + /* allocate based on nr_cpu_ids */ >>> + kstat_irqs_legacy = alloc_bootmem(NR_IRQS_LEGACY * nr_cpu_ids * >>> + sizeof(int)); >>> + >>> for (i = 0; i < legacy_count; i++) { >>> desc[i].irq = i; >>> - desc[i].kstat_irqs = kstat_irqs_legacy[i]; >>> + desc[i].kstat_irqs = kstat_irqs_legacy + i * NR_IRQS_LEGACY; >> here should be >> >> + desc[i].kstat_irqs = kstat_irqs_legacy + i * nr_cpu_ids; >> >> YH > > Hmm, thanks! (I wonder why I wanted it the other way? Oh well.) > > I'll make an append patch to fix it. > > Thanks, > Mike
I'll push this to my cpus4096-for-ingo.git tree:
Subject: irq: fix initialization of legacy kstat irqs
Impact: fix bug with legacy kstat irqs
The sectioning of the allocated kstat_irqs_legacy should use nr_cpu_ids instead of NR_IRQS_LEGACY.
Thanks to Yinghai for pointing this out.
Signed-off-by: Mike Travis <travis@sgi.com> --- kernel/irq/handle.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- linux-2.6-for-ingo.orig/kernel/irq/handle.c +++ linux-2.6-for-ingo/kernel/irq/handle.c @@ -155,7 +155,7 @@ int __init early_irq_init(void) for (i = 0; i < legacy_count; i++) { desc[i].irq = i; - desc[i].kstat_irqs = kstat_irqs_legacy + i * NR_IRQS_LEGACY; + desc[i].kstat_irqs = kstat_irqs_legacy + i * nr_cpu_ids; lockdep_set_class(&desc[i].lock, &irq_desc_lock_class); init_alloc_desc_masks(&desc[i], 0, true); irq_desc_ptrs[i] = desc + i;
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