linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: John Stultz <jstultz@google.com>
To: Maxime Ripard <mripard@kernel.org>
Cc: "Sumit Semwal" <sumit.semwal@linaro.org>,
	"Benjamin Gaignard" <benjamin.gaignard@collabora.com>,
	"Brian Starkey" <Brian.Starkey@arm.com>,
	"T.J. Mercier" <tjmercier@google.com>,
	"Christian König" <christian.koenig@amd.com>,
	"Marek Szyprowski" <m.szyprowski@samsung.com>,
	"Robin Murphy" <robin.murphy@arm.com>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"David Hildenbrand" <david@kernel.org>,
	"Lorenzo Stoakes" <lorenzo.stoakes@oracle.com>,
	"Liam R. Howlett" <Liam.Howlett@oracle.com>,
	"Vlastimil Babka" <vbabka@suse.cz>,
	"Mike Rapoport" <rppt@kernel.org>,
	"Suren Baghdasaryan" <surenb@google.com>,
	"Michal Hocko" <mhocko@suse.com>,
	linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org,
	linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org,
	iommu@lists.linux.dev, linux-mm@kvack.org
Subject: Re: [PATCH 0/7] dma-buf: heaps: Turn heaps into modules
Date: Wed, 25 Feb 2026 10:51:30 -0800	[thread overview]
Message-ID: <CANDhNCqk9Uk4aXHhUsL4hR1GHNmWZnH3C9Np-A02wdi+J3D7tA@mail.gmail.com> (raw)
In-Reply-To: <20260225-dma-buf-heaps-as-modules-v1-0-2109225a090d@kernel.org>

On Wed, Feb 25, 2026 at 8:42 AM Maxime Ripard <mripard@kernel.org> wrote:
>
> The recent introduction of heaps in the optee driver [1] made possible
> the creation of heaps as modules.
>
> It's generally a good idea if possible, including for the already
> existing system and CMA heaps.
>
> The system one is pretty trivial, the CMA one is a bit more involved,
> especially since we have a call from kernel/dma/contiguous.c to the CMA
> heap code. This was solved by turning the logic around and making the
> CMA heap call into the contiguous DMA code.
>

So heaps-as-modules is common in the Android kernels, and was
attempted to be upstreamed long ago:
  https://lore.kernel.org/lkml/20191025234834.28214-1-john.stultz@linaro.org/

And it got a fairly chilly reception, but maybe having the additional
optee heap (as well as other proposed heaps) might sway folks on this
now.

There is also the kref bits you might need (which Android still carries):
  https://lore.kernel.org/lkml/20200725032633.125006-1-john.stultz@linaro.org/

thanks
-john


      parent reply	other threads:[~2026-02-25 18:51 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-02-25 16:41 Maxime Ripard
2026-02-25 16:41 ` [PATCH 1/7] dma: contiguous: Turn heap registration logic around Maxime Ripard
2026-02-25 19:32   ` T.J. Mercier
2026-02-25 16:41 ` [PATCH 2/7] mm: cma: Export cma_alloc and cma_release Maxime Ripard
2026-02-25 19:34   ` T.J. Mercier
2026-02-25 16:41 ` [PATCH 3/7] mm: cma: Export cma_get_name Maxime Ripard
2026-02-25 19:34   ` T.J. Mercier
2026-02-25 16:41 ` [PATCH 4/7] mm: cma: Export dma_contiguous_default_area Maxime Ripard
2026-02-25 19:52   ` T.J. Mercier
2026-02-25 16:41 ` [PATCH 5/7] dma-buf: heaps: Export mem_accounting parameter Maxime Ripard
2026-02-25 19:53   ` T.J. Mercier
2026-02-25 16:41 ` [PATCH 6/7] dma-buf: heaps: cma: Turn the heap into a module Maxime Ripard
2026-02-25 19:54   ` T.J. Mercier
2026-02-25 16:41 ` [PATCH 7/7] dma-buf: heaps: system: " Maxime Ripard
2026-02-25 19:55   ` T.J. Mercier
2026-02-25 18:51 ` John Stultz [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CANDhNCqk9Uk4aXHhUsL4hR1GHNmWZnH3C9Np-A02wdi+J3D7tA@mail.gmail.com \
    --to=jstultz@google.com \
    --cc=Brian.Starkey@arm.com \
    --cc=Liam.Howlett@oracle.com \
    --cc=akpm@linux-foundation.org \
    --cc=benjamin.gaignard@collabora.com \
    --cc=christian.koenig@amd.com \
    --cc=david@kernel.org \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=iommu@lists.linux.dev \
    --cc=linaro-mm-sig@lists.linaro.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-media@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=lorenzo.stoakes@oracle.com \
    --cc=m.szyprowski@samsung.com \
    --cc=mhocko@suse.com \
    --cc=mripard@kernel.org \
    --cc=robin.murphy@arm.com \
    --cc=rppt@kernel.org \
    --cc=sumit.semwal@linaro.org \
    --cc=surenb@google.com \
    --cc=tjmercier@google.com \
    --cc=vbabka@suse.cz \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox