From: Wathsala Wathawana Vithanage <wathsala.vithanage@arm.com>
To: "Mattias Rönnblom" <hofors@lysator.liu.se>,
"dev@dpdk.org" <dev@dpdk.org>,
"thomas@monjalon.net" <thomas@monjalon.net>,
"Ferruh Yigit" <ferruh.yigit@amd.com>,
"Andrew Rybchenko" <andrew.rybchenko@oktetlabs.ru>
Cc: nd <nd@arm.com>, Dhruv Tripathi <Dhruv.Tripathi@arm.com>,
nd <nd@arm.com>
Subject: RE: [RFC v2] ethdev: an API for cache stashing hints
Date: Thu, 24 Oct 2024 14:59:17 +0000 [thread overview]
Message-ID: <PAWPR08MB89094DCCFC827013D50948E69F4E2@PAWPR08MB8909.eurprd08.prod.outlook.com> (raw)
In-Reply-To: <f95e2d97-c312-4a0d-9182-2cce5d57a4a6@lysator.liu.se>
> If we had a hwtopo API in DPDK, we could just use a node id in such a graph
> (of CPUs and caches) to describe were the data ideally would land.
> In such a case, you could have a node id for DDR as well, and thus you could
> drop the notion of "stashing". Just a "drop off the data here, please, if you
> can" API.
>
> I don't think this API and its documentation should talk about what the "CPU"
> needs, since it's somewhat misleading.
>
> For example, you can imagine you want the packet payload to land in the LLC,
> even though it's not for any CPU to consume, in case you know with some
> certaintly that the packet will soon be transmitted (and thus consumed by the
> NIC).
>
> The same scenario can happen, the consumer is an accelerator (e.g., a crypto
> engine).
>
> Likewise, you may know that the whole packet will be read by some CPU core,
> but you also know the system tends to buffer packets before they are being
> processed. In such a case, it's better to go to DRAM right away, to avoid
> trashing the LLC (or some other cache).
>
> Also, why do you need to use the word "host"? Seems like a PCI thing.
> This may be implemented in PCI, but surely can be done (and has been
> done) without PCI.
>
Thanks, Mattias. V2 is outdated, please provide feedback on V3.
prev parent reply other threads:[~2024-10-24 14:59 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-15 22:11 Wathsala Vithanage
2024-07-17 2:27 ` Stephen Hemminger
2024-07-18 18:48 ` Wathsala Wathawana Vithanage
2024-07-20 3:05 ` Honnappa Nagarahalli
2024-07-17 10:32 ` Konstantin Ananyev
2024-07-22 11:18 ` Ferruh Yigit
2024-07-26 20:01 ` Wathsala Wathawana Vithanage
2024-09-22 21:43 ` Ferruh Yigit
2024-10-04 17:52 ` Stephen Hemminger
2024-10-04 18:46 ` Wathsala Wathawana Vithanage
2024-10-21 1:52 ` [RFC v3 0/2] An API for Stashing Packets into CPU caches Wathsala Vithanage
2024-10-21 1:52 ` [RFC v3 1/2] pci: introduce the PCIe TLP Processing Hints API Wathsala Vithanage
2024-10-21 1:52 ` [RFC v3 2/2] ethdev: introduce the cache stashing hints API Wathsala Vithanage
2024-10-21 7:36 ` Morten Brørup
2024-10-24 5:49 ` Jerin Jacob
2024-10-24 6:59 ` Morten Brørup
2024-10-24 15:12 ` Wathsala Wathawana Vithanage
2024-10-24 15:04 ` Wathsala Wathawana Vithanage
2024-10-21 7:35 ` [RFC v3 0/2] An API for Stashing Packets into CPU caches Chenbo Xia
2024-10-21 12:01 ` Wathsala Wathawana Vithanage
2024-10-22 1:12 ` Stephen Hemminger
2024-10-22 18:37 ` Wathsala Wathawana Vithanage
2024-10-22 21:23 ` Stephen Hemminger
2024-10-23 17:59 ` [RFC v2] ethdev: an API for cache stashing hints Mattias Rönnblom
2024-10-23 20:18 ` Stephen Hemminger
2024-10-24 14:59 ` Wathsala Wathawana Vithanage [this message]
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