Re: [RFC] new totalmem= boot parameter

[Keir Fraser <keir.fraser@eu.citrix.com>]

On 20/07/2010 22:26, "Sarina Canelake" <sarina.canelake@oracle.com> wrote:

>> It doesn't sound *very* useful. But then neither is mem= really. We can add
>> something like this if you really need it. So what's the motivation?
>> 
> 
> I found it useful while I was testing various core dumping capabilities.
> Using a boot-time argument to limit memory eliminates the need for pulling
> out DIMMs (which I couldn't do anyways, as the machines I was working
> on are remote). However mem= didn't suffice for this purpose
> beyond 3 Gb since, as I mentioned, it limits the physical address
> rather than the amount of RAM, which is what I thought it was
> supposed to do. Hence the implementation of totalmem=, which made my
> 16Gb+ boxes capable of imitating various, specific smaller configurations.

Okay, I applied a reimplemented form of your patch as xen-unstable:21837.
The option is named availmem rather than totalmem. I think it's a slightly
better name.

 -- Keir

> Alternatively, if mem= isn't used very frequently, perhaps it wouldn't
> be a bad idea to simply update the functionality of mem= to limit the
> total memory rather than the physical address.