__memblock_f...nge_top_down(9)

💅 __memblock_find_range_top_down — Kernel API Manual ✨

okay bestie, so this page lives in the kernel API manual, the function is __memblock_find_range_top_down, and it's literally the finder-of-free-space that starts from the top and works its way down. no cap. 🫶

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✨ NAME ✨

__memblock_find_range_top_down — find free area utility, in top-down 🌈

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🎀 SYNOPSIS 🎀

phys_addr_t __init_memblock __memblock_find_range_top_down (phys_addr_t
start , phys_addr_t end , phys_addr_t size , phys_addr_t align , int nid
, enum memblock_flags flags );

like, look at her. phys_addr_t return type, __init_memblock on the front, six whole arguments. main character energy honestly 👑

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💖 ARGUMENTS 💖

• start — start of candidate range. the beginning, the origin story, where we start looking 🦋
• end — end of candidate range, and it can be MEMBLOCK_ALLOC_ANYWHERE or MEMBLOCK_ALLOC_ACCESSIBLE. yes those are the two special values, write them down 📝
• size — size of free area to find. how much room you're hunting for, no more no less 💅
• align — alignment of free area to find. she has standards, the address must line up ✨
• nid — nid of the free area to find, and NUMA_NO_NODE means "any node, idc, surprise me" 🙈
• flags — pick from blocks based on memory attributes ⭐

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🌸 DESCRIPTION 🌸

so this is a utility that gets called from memblock_find_in_range_node, and it finds a free area top-down. that's it, that's the whole vibe. 💀

lowkey iconic how short this description is. the function does one thing and does it slay.

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💜 RETURN 💜

Found address on success, 0 on failure. so like, if it comes back with 0? that's a no. that's a failure bestie, don't get it twisted 😭

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🔥 SEE ALSO 🔥

the whole memblock friend group, fr fr — every single one of them 💖

• Kernel file ./mm/memblock.c
• memblock overview(9)
• __memblock_find_range_bottom_up(9)
• memblock_find_in_range_node(9)
• memblock_find_in_range(9)
• memblock_discard(9)
• memblock_double_array(9)
• memblock_merge_regions(9)
• memblock_insert_region(9)
• memblock_add_range(9)
• memblock_add_node(9)
• memblock_add(9)
• memblock_validate_numa_coverage(9)
• memblock_isolate_range(9)
• memblock_free(9)
• memblock_phys_free(9)
• memblock_setclr_flag(9)
• memblock_mark_hotplug(9)
• memblock_clear_hotplug(9)
• memblock_mark_mirror(9)
• memblock_mark_nomap(9)
• memblock_clear_nomap(9)
• memblock_reserved_mark_noinit(9)
• memblock_reserved_mark_kern(9)
• memblock_mark_kho_scratch(9)
• memblock_clear_kho_scratch(9)
• __next_mem_range(9)
• __next_mem_range_rev(9)
• memblock_set_node(9)
• memblock_alloc_range_nid(9)
• memblock_phys_alloc_range(9)
• memblock_phys_alloc_try_nid(9)
• memblock_alloc_internal(9)
• memblock_alloc_exact_nid_raw(9)
• memblock_alloc_try_nid_raw(9)
• memblock_alloc_hugetlb(9)
• memblock_alloc_try_nid(9)
• __memblock_alloc_or_panic(9)
• memblock_estimated_nr_free_pages(9)
• memblock_is_region_memory(9)
• memblock_is_region_reserved(9)
• memblock_free_all(9)
• reserve_mem_find_by_name(9)
• reserve_mem_release_by_name(9)

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anyway that's the page!! this one comes from ./mm, dated October 2026, and it's filed under __memblock_f...nge_top_down(9) in the kernel API manual. go find your free area top-down and slay, bestie 💅🎀💖