memblock_set_node(9)

🌸 memblock_set_node(9) 🌸

okay bestie, welcome to the memblock_set_node page — it's from the Kernel API Manual, section 9, and it's honestly kind of a little legend. it's the function that goes "hey, this chunk of memory? it belongs to this NUMA node now 💅" and just makes it happen. no cap.

---

✨ SYNOPSIS ✨

int __init_memblock memblock_set_node (phys_addr_t base , phys_addr_t size ,
                                       struct memblock_type *type , int nid );

like, look at that signature. it ate. 🫶

---

🎀 ARGUMENTS 🎀

• base — the base of the area you're setting the node ID for. the starting point, the origin story, the "we begin here." 📍
• size — the size of that area. how much memory we're talking about. the span, the range, the vibe check radius. 📏
• type — which memblock type we're setting the node ID for. it's a struct memblock_type *, so yes bestie, pointer, don't forget the *. 🧚
• nid — the actual node ID you want to set. the number. the whole point of the whole function. 👑

---

💖 DESCRIPTION 💖

so here's the tea: this bad boy sets the nid of memblock type regions inside [base, base + size) to nid. literally exactly that. that's the whole job and it does it slayfully.

and the iconic part? regions which cross the area boundaries are split as necessary. so if a region is like half in, half out of your range, it doesn't just give up — it splits it. main character energy fr fr. 🔥

---

⭐ RETURN ⭐

• 0 on success — we love a zero. we stan a zero. 🎉
• -errno on failure — something went sideways and it's telling you why in errno form. 😭

---

🦋 SEE ALSO 🦋

okay this list is LONG so buckle up, buttercup — every single one of these is here, no skipping, no cutting corners:

• Kernel file ./mm/memblock.c 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_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_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)

iykyk, that's the whole memblock friend group right there. 🌈

---

and that's the page, bestie! this one lives in the source tree at ./mm and the version stamp says October 2026 — so yeah, timestamped and everything. now go set some node IDs, you gorgeous kernel gremlin 💜✨🎀