Re: [00/14] Virtual Compound Page Support V3

[Christoph Lameter]

On Sat, 22 Mar 2008, Arjan van de Ven wrote:

> can you document the drawback of large, frequent vmalloc() allocations at least?

Ok. Lets add some documentation about this issue and some other 
things. A similar suggestion was made by Kosaki-san.

> On 32 bit x86, the effective vmalloc space is 64Mb or so (after various PCI bars are ioremaped),
> so if this type of allocation is used for a "scales with nr of ABC" where "ABC" is workload dependent,
> there's a rather abrupt upper limit to this.
> Not saying that that is a flaw of your patch, just pointing out that we should discourage usage of 
> the "scales with nr of ABC" (for example "one for each thread") kind of things.

I better take out any patches that do large scale allocs then.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/