From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
To: Alejandro Lucero <alejandro.lucero@netronome.com>
Cc: "Stojaczyk, DariuszX" <dariuszx.stojaczyk@intel.com>,
dev <dev@dpdk.org>, "stable@dpdk.org" <stable@dpdk.org>
Subject: Re: [dpdk-stable] [dpdk-dev] [PATCH] memory: do not use base-virtaddr in secondary processes
Date: Tue, 19 Jun 2018 11:27:34 +0100 [thread overview]
Message-ID: <01d715f0-50aa-9d66-1cbb-1c5e4af0e3c6@intel.com> (raw)
In-Reply-To: <CAD+H991hSrpB4T8Fcm-umj_Hv4XC5FZVuhXqHZ9f8sxUKLZzwg@mail.gmail.com>
On 19-Jun-18 11:23 AM, Alejandro Lucero wrote:
>
>
> On Tue, Jun 19, 2018 at 10:24 AM, Burakov, Anatoly
> <anatoly.burakov@intel.com <mailto:anatoly.burakov@intel.com>> wrote:
>
> On 18-Jun-18 9:12 PM, Stojaczyk, DariuszX wrote:
>
>
>
> -----Original Message-----
> From: Alejandro Lucero
> [mailto:alejandro.lucero@netronome.com
> <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>
> <mailto: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.
>
>
> Hi Alejandro,
>
> To solve this problem, one possible approach would be to have
> maximum VA address, and allocate memory downwards, rather than
> upwards. Is that by any chance approximate contents of your RFC? :)
>
>
> Hi Anatoly,
>
> There's a lot of space below 1TB, but this specific upper limit is just
> in the NFP case. My RFC will propose a generic solution assuming there
> could be other devices in the future, and not just NIC devices, which
> could have also some sort of limitation.
OK, looking forward to it.
> The problem is, those devices
> limitations can not be known at memory initialization time, so some sort
> of check is required afterwards, once the devices have been proved and
> initialised.
>
Presumably, device driver would be in the best position to know things
like that, no? Maybe a new device flag and an API to query such things
from all devices?
--
Thanks,
Anatoly
next prev parent reply other threads:[~2018-06-19 10:27 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-18 19:53 [dpdk-stable] " Dariusz Stojaczyk
2018-06-18 17:21 ` [dpdk-stable] [dpdk-dev] " Alejandro Lucero
2018-06-18 19:03 ` Stojaczyk, DariuszX
2018-06-18 19:33 ` Alejandro Lucero
2018-06-18 20:12 ` Stojaczyk, DariuszX
2018-06-19 9:24 ` Burakov, Anatoly
2018-06-19 10:23 ` Alejandro Lucero
2018-06-19 10:27 ` Burakov, Anatoly [this message]
2018-06-19 11:48 ` Alejandro Lucero
2018-06-19 9:21 ` [dpdk-stable] " Burakov, Anatoly
2018-07-12 22:08 ` [dpdk-stable] [dpdk-dev] " Thomas Monjalon
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