Messages in this thread | | | Date | Mon, 7 Aug 2006 16:55:12 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] x86_64: Make NR_IRQS configurable in Kconfig |
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On Mon, 07 Aug 2006 16:10:14 -0600 ebiederm@xmission.com (Eric W. Biederman) wrote:
> +/* We can be setup to receive at most NR_CPUS*224 irqs simultaneously */ > +#define NR_IRQS (CONFIG_NR_IRQS)
We know that setting this high can cause machines to run out of per-cpu memory, so we're handing people a foot blowing-off tool here.
And it's a pretty nasty one because it can get people into the situation where the kernel worked fine for those who released it, but users who happen to load more modules (or the right combination of them) will experience per-cpu memory exhaustion.
So shouldn't we being scaling the per-cpu memory as well?
If so, I'd suggest that we special-case that huge kstat structure. We can calculate its size exactly, so how about we do:
#define SIZE_OF_KSTAT_THING <complicated expression> #define PERCPU_ENOUGH_ROOM 32768
#define PERCPU_ENOUGH_ROOM_WHICH_WE_REALLY_USE \ PERCPU_ENOUGH_ROOM + SIZE_OF_KSTAT_THING
?
(And as it's a critical managed resource, I'm thinking that we should be adding some /proc reporting of the per-cpu memory consumption..) - 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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