From: Alejandro Lucero <alejandro.lucero@netronome.com>
To: "Burakov, Anatoly" <anatoly.burakov@intel.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 12:48:50 +0100 [thread overview]
Message-ID: <CAD+H990E8VMQ94Z8YtRPsTTkLpp-rxdbjg+W33HDU5SJHbhhtw@mail.gmail.com> (raw)
In-Reply-To: <01d715f0-50aa-9d66-1cbb-1c5e4af0e3c6@intel.com>
On Tue, Jun 19, 2018 at 11:27 AM, Burakov, Anatoly <
anatoly.burakov@intel.com> wrote:
> 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?
>
>
Right. I plan to add a per-device DMA mask, just mimicking what the kernel
has.
> --
> Thanks,
> Anatoly
>
next prev parent reply other threads:[~2018-06-19 11:48 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
2018-06-19 11:48 ` Alejandro Lucero [this message]
2018-06-19 9:21 ` [dpdk-stable] " Burakov, Anatoly
2018-07-12 22:08 ` [dpdk-stable] [dpdk-dev] " Thomas Monjalon
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