Re: [PATCH] x86_64: Make NR_IRQS configurable in Kconfig

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, 07 Aug 2006 16:10:14 -0600
[email protected] (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 [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux