dma_alloc_contiguous(9)

💖 dma_alloc_contiguous(9) 💖

okay bestie, so this is dma_alloc_contiguous(9) straight out of the Kernel API Manual — it's the function that scores you some contiguous pages and honestly? it's kind of the main character of ./kernel/dma. let's get into it 🫶

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✨ SYNOPSIS ✨

struct page * dma_alloc_contiguous (struct device *dev , size_t size ,
       gfp_t gfp );

like, that's the whole vibe. it hands you back a struct page *, periodt. 👑

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🎀 ARGUMENTS 🎀

• dev — pointer to the device you're doing this allocation for, iykyk — it's their allocation, not yours 💅
• size — the requested allocation size. yeah. how much you want. 🍓
• gfp — the allocation flags. the little knobs that tell the allocator how to behave ✨

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🌸 DESCRIPTION 🌸

so here's the tea ☕ — it tries to use the device specific contiguous memory area if one is available. and if that's not it, it tries the per-numa cma. and if the allocation fails? no worries bestie, it will fallback to try the default global one. three-tier slay. 🔥

also important, fr fr: it bypasses one-page size of allocations from the per-numa and global area. why? because the addresses within one page are always contiguous, so there's literally no need to waste CMA pages for that kind of thing 🧚 and lowkey it also helps reduce fragmentations. we love an efficient icon. 💜

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🦋 SEE ALSO 🦋

• Kernel file ./kernel/dma/contiguous.c
• dma_contiguous_get_area_by_idx(9)
• dma_contiguous_reserve(9)
• dma_contiguous_reserve_area(9)
• dma_alloc_from_contiguous(9)
• dma_release_from_contiguous(9)
• dma_free_contiguous(9)

like, go read the whole friend group, they're all connected 💖

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and that's the page!! 🎀 brought to you from ./kernel/dma, dated October 2026, and yeah — this is dma_alloc_contiguous(9) signing off. mwah 💋✨