[PATCH 0/3] dma-mapping: Improve atomic pool behaviour

[Robin Murphy <robin.murphy@arm.com>]

Hi all,

These days we have somewhat of a matrix of mm zones that may or may not
exist and may or may not be empty, which the per-zone atomic pool logic
doesn't actually handle all that well. It's not all that difficult to
improve robustness and reduce redundancy, so that's what this series
aims for.

I initially wrote this just because I happened to be looking through the
boot log of one of my boards and had one of those out-of-the-blue
realisations of "hang on, why *is* it allocating pools for zones it
doesn't even have memory in?", but coincidentally, it seems that others
happened to notice related aspects around the same time[1][2]. This is
my attempt to sort it all out properly.

I guess this could go via either the dma-mapping or mm tree, whichever
maintainers prefer.

Thanks,
Robin.


[1] https://lore.kernel.org/linux-iommu/20260112065857.3137331-1-vladimir.kondratiev@mobileye.com/
[2] https://lore.kernel.org/linux-iommu/20260112104749.4132641-1-s-adivi@ti.com/

Robin Murphy (3):
  dma/pool: Improve pool lookup
  mm_zone: Generalise has_managed_dma()
  dma/pool: Avoid allocating redundant pools

 include/linux/mmzone.h |  9 +++++----
 kernel/dma/pool.c      | 27 ++++++++++++++++++---------
 mm/page_alloc.c        |  8 ++------
 3 files changed, 25 insertions(+), 19 deletions(-)

-- 
2.34.1