memblock_isolate_range(9)

💅 memblock_isolate_range(9) 💅

okay bestie, welcome to the Kernel API Manual page for memblock_isolate_range(9) — manual name folded in right here, no boring header-line copy-paste energy. This one is about carving a range out of a memblock type so the regions don’t cross the edges. Slay. 🧚

🌸 NAME 🌸

memblock_isolate_range — isolate given range into disjoint memblocks.

✨ SYNOPSIS ✨

the signature, verbatim, no edits, no cap:

int __init_memblock memblock_isolate_range (struct memblock_type *type ,
       phys_addr_t base , phys_addr_t size , int *start_rgn , int *end_rgn );

🎀 ARGUMENTS 🎀

• type — memblock type to isolate range for.
• base — base of range to isolate.
• size — size of range to isolate.
• start_rgn — out parameter for the start of isolated region.
• end_rgn — out parameter for the end of isolated region.

🦋 DESCRIPTION 🦋

Walk type and ensure that regions don’t cross the boundaries defined by [base, base + size). Crossing regions are split at the boundaries, which may create at most two more regions.

The index of the first region inside the range is returned in *start_rgn, and the index of the first region after the range is returned in *end_rgn. periodt 💅

🔥 RETURN 🔥

0 on success, -errno on failure. that’s the whole vibe check.

👑 SEE ALSO 👑

the whole squad, in order, iykyk:

• Kernel file ./mm/memblock.c and memblock overview(9)
• __memblock_find_range_bottom_up(9)
• __memblock_find_range_top_down(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_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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xoxo, source/version bestie: ./mm, dated October 2026 — bye bestie! 🎀💖