From: Jason Gunthorpe <jgg@ziepe.ca>
To: Luigi Rizzo <lrizzo@google.com>
Cc: "David Hildenbrand (Arm)" <david@kernel.org>,
Luigi Rizzo <rizzo.unipi@gmail.com>,
Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
Robin Murphy <robin.murphy@arm.com>,
Christoph Hellwig <hch@lst.de>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@kernel.org>,
"David S . Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@kernel.org>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J . Wysocki" <rafael@kernel.org>,
Danilo Krummrich <dakr@kernel.org>,
Jonathan Corbet <corbet@lwn.net>,
Jesper Dangaard Brouer <hawk@kernel.org>,
Ilias Apalodimas <ilias.apalodimas@linaro.org>,
Willem de Bruijn <willemb@google.com>,
Kuniyuki Iwashima <kuniyu@google.com>,
Joshua Washington <joshwash@google.com>,
Harshitha Ramamurthy <hramamurthy@google.com>,
Saeed Mahameed <saeedm@nvidia.com>,
Tariq Toukan <tariqt@nvidia.com>,
Tony Nguyen <anthony.l.nguyen@intel.com>,
Przemek Kitszel <przemyslaw.kitszel@intel.com>,
Alexander Lobakin <aleksander.lobakin@intel.com>,
Michael Chan <michael.chan@broadcom.com>,
Pavan Chebbi <pavan.chebbi@broadcom.com>,
iommu@lists.linux.dev, netdev@vger.kernel.org,
linux-mm@kvack.org, driver-core@lists.linux.dev,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC: DMA_PMD 00/22] DMA_PMD: PMD_SIZE-backed IO buffer pools
Date: Thu, 22 Oct 2026 17:12:29 -0300 [thread overview]
Message-ID: <20261022201229.GH3381610@ziepe.ca> (raw)
In-Reply-To: <CAMOZA0+6kAbwgNwGTsCT5AqpwcZKz4pziEGC9UpHkNCVoqrF-Q@mail.gmail.com>
On Sat, Oct 17, 2026 at 07:11:28PM +0200, Luigi Rizzo wrote:
> > We should probably just find a way to describe that this is a POOL that focuses
> > on physical contiguity in some configured granularity.
>
> Before embarking in a global renaming, I would like to get opinions on
> acceptable alternative names (possibly with a short prefix usable for
> identifiers in the code). I could think of the following
>
> DMA_PMAP (for PreMapped or Persistent Mapped)
> or, ahemm...
> DMA_PISA (Pooled IOMMU Superpage Allocator)
> both using dmap_ for internal name prefixes
Can someone explain what outside netdev would use this? And why you
couldn't do this in the netdev page pool?
It is not a common workload to have the DMA allocator be the one that
allocates the memory. Usually we are DMA'ing from memory that was
allocated someplace else.
I think Robin is right, this is just a special case of the dma pool,
and it certainly shouldn't be something as grandiose as a subsystem..
Jason
next prev parent reply other threads:[~2026-10-22 20:12 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-03 21:22 Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 01/22] iommu/dma: introduce CONFIG_DMA_PMD and metadata table Luigi Rizzo
2026-10-03 21:44 ` Randy Dunlap
2026-10-04 9:14 ` Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 02/22] iommu/dma: add DMA_PMD pool lifecycle and page recycle hook Luigi Rizzo
2026-10-10 2:59 ` kernel test robot
2026-10-03 21:22 ` [RFC: DMA_PMD 03/22] mm: Add split_page_compound() Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 04/22] iommu/dma: add DMA_PMD pool block allocation Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 05/22] iommu/dma: Global cap and shrinker for DMA_PMD pool memory Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 06/22] iommu/dma: reserve a per-domain IOVA window for DMA_PMD pages Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 07/22] iommu/dma: release DMA_PMD domain mappings on domain teardown Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 08/22] iommu/dma: use per-domain IOVA window to map DMA_PMD memory Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 09/22] iommu/dma: Add DMA_PMD arena allocator Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 10/22] driver core: Add per-device dma_pmd_* sysfs attributes Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 11/22] dma-mapping: Use DMA_PMD arena for dma_alloc_attrs() Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 12/22] net/core: Use per-CPU DMA_PMD pools for skb_page_frag_refill() Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 13/22] net/core: Use DMA_PMD for page_pool memory Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 14/22] iommu/dma: Support decrypted and pinned DMA_PMD pages Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 15/22] iommu/dma: Add background page scrubber for DMA_PMD pools Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 16/22] iommu/dma: Add per-NUMA-node PMD page reservoir Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 17/22] net/gve: Use DMA_PMD memory for RX buffers Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 18/22] net/gve: Use DMA_PMD memory for tx header bounce buffers Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 19/22] net/mlx5e: " Luigi Rizzo
2026-10-14 17:22 ` Dragos Tatulea
2026-10-14 17:50 ` Dragos Tatulea
2026-10-14 18:28 ` Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 20/22] net/idpf: " Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 21/22] net/bnxt: " Luigi Rizzo
2026-10-03 21:22 ` [RFC: DMA_PMD 22/22] iommu/dma: Add DMA_PMD statistics and debugfs Luigi Rizzo
2026-10-11 9:02 ` [RFC: DMA_PMD 00/22] DMA_PMD: PMD_SIZE-backed IO buffer pools Pranjal Shrivastava
2026-10-12 13:51 ` David Hildenbrand (Arm)
2026-10-12 14:45 ` Luigi Rizzo
2026-10-12 19:43 ` David Hildenbrand (Arm)
2026-10-13 10:42 ` Robin Murphy
2026-10-14 10:47 ` David Hildenbrand (Arm)
2026-10-14 11:05 ` Luigi Rizzo
2026-10-17 17:11 ` Luigi Rizzo
2026-10-22 20:12 ` Jason Gunthorpe [this message]
2026-10-12 14:49 ` Mostafa Saleh
2026-10-12 15:02 ` Luigi Rizzo
2026-10-14 17:28 ` Dragos Tatulea
2026-10-14 18:14 ` Luigi Rizzo
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