mirror-linux/kernel/dma
Robin Murphy c6ccd09880 dma/pool: Avoid allocating redundant pools
On smaller systems, e.g. embedded arm64, it is common for all memory
to end up in ZONE_DMA32 or even ZONE_DMA. In such cases it is redundant
to allocate a nominal pool for an empty higher zone that just ends up
coming from a lower zone that should already have its own pool anyway.
We already have logic to skip allocating a ZONE_DMA pool when that is
empty, so generalise that to save memory in the case of other zones too.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Vladimir Kondratiev <vladimir.kondratiev@mobileye.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/8ab8d8a620dee0109f33f5cb63d6bfeed35aac37.1768230104.git.robin.murphy@arm.com
2026-01-14 11:00:00 +01:00
..
Kconfig dma-debug: remove DMA_API_DEBUG_SG 2024-10-29 08:53:37 +01:00
Makefile dma-mapping: clearly mark DMA ops as an architecture feature 2024-09-04 07:08:51 +03:00
coherent.c dma-coherent: Warn if OF reserved memory is beyond current coherent DMA mask 2025-04-22 17:44:09 +02:00
contiguous.c dma: contiguous: Reserve default CMA heap 2025-10-18 21:31:21 +05:30
debug.c dma-debug: don't report false positives with DMA_BOUNCE_UNALIGNED_KMALLOC 2025-10-15 13:24:33 -07:00
debug.h dma-mapping: export new dma_*map_phys() interface 2025-09-12 00:18:21 +02:00
direct.c VFIO updates for v6.19-rc1 2025-12-04 18:42:48 -08:00
direct.h dma-mapping: convert dma_direct_*map_page to be phys_addr_t based 2025-09-12 00:18:20 +02:00
dummy.c dma-mapping: convert dummy ops to physical address mapping 2025-10-29 10:27:29 +01:00
map_benchmark.c tools/dma: move dma_map_benchmark from selftests to tools/dma 2025-10-29 09:41:40 +01:00
mapping.c dma-mapping: remove unused map_page callback 2025-10-29 10:27:31 +01:00
ops_helpers.c dma-mapping: remove unused map_page callback 2025-10-29 10:27:31 +01:00
pool.c dma/pool: Avoid allocating redundant pools 2026-01-14 11:00:00 +01:00
remap.c dma-remap: drop nth_page() in dma_common_contiguous_remap() 2025-09-21 14:22:06 -07:00
swiotlb.c mm: make INVALID_PHYS_ADDR a generic macro 2025-11-16 17:28:26 -08:00