Re: [dpdk-dev] [PATCH] memory: do not use base-virtaddr in secondary processes

["Stojaczyk, DariuszX" <dariuszx.stojaczyk@intel.com>]

> -----Original Message-----
> From: Alejandro Lucero [mailto:alejandro.lucero@netronome.com]
> Sent: Monday, June 18, 2018 9:33 PM
> 
> On Mon, Jun 18, 2018 at 8:03 PM, Stojaczyk, DariuszX
> <dariuszx.stojaczyk@intel.com <mailto:dariuszx.stojaczyk@intel.com> >
> wrote:
> 
> 	Can you point me out to an NFP guide or some code that describes
> this in more detail?
> 
> 
> 
> As I said, I'm working on a RFC. I will send something shortly. But I could give
> you an advance: the hugepages needs to be mapped below certain virtual
> address, 1TB, and I'm afraid that includes the primary and also the
> secondary processes. At least if any process can send or receive packets
> to/from a NFP.
> 
> 

Thanks, I'm pretty sure we're safe, then.

> 
> 	If we're talking about base-virtaddr for hugepages, then that's always
> inherited from the primary process, regardless of what base-virtaddr is
> supplied to the secondary.
> 
> 
> 
> 
> But, is not your patch avoiding to use that base-virtaddr for secondary
> processes?

I see now that the patch name is slightly misleading. Maybe I shouldn’t pick such a catchy title. Let me clarify: As of DPDK 18.05, --base-virtaddr param for secondary process applications only affects that shadow memseg metadata that's not useful for anyone, but can still do a lot of harm. Hugepage memory in secondary processes is always mapped to the same addresses the primary process uses.

D.