__vcalloc(9)

✨ __vcalloc ✨

okay so bestie, this is a kernel API manual page (that's the 9 section, iykyk) and honestly? it's a little legend. it's the allocator that hands you memory and zeroes it for you, for a virtually contiguous array. no cap, it does both 💅

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🎀 NAME 🎀

__vcalloc — allocate and zero memory for a virtually contiguous array.

like, it's giving "malloc but make it vmalloc and also please clear it for me" 🌸

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🦋 SYNOPSIS 🦋

void * __vcalloc (size_t n , size_t size , gfp_t flags );

that's the whole vibe. three args, one pointer back. slay ✨

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💖 ARGUMENTS 💖

• n — number of elements. how many little guys you want in your array 🫶
• size — element size. how big each little guy is, in bytes.
• flags — the type of memory to allocate (see kmalloc). yes bestie, actually go read kmalloc, it's right there. this is where you say what kind of memory you're in the mood for 👑

ngl, the args are tiny but they matter. n × size is the whole math of your array and flags is the personality of the allocation.

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🔥 SEE ALSO 🔥

so first up, this thing lives in the kernel file ./mm/util.c — that's its home address, remember it 🏡

and then, the whole friend group, in exactly this order:

• kfree_const(9)
• __kmemdup_nul(9)
• kstrdup(9)
• kstrdup_const(9)
• kstrndup(9)
• kmemdup(9)
• kmemdup_array(9)
• kvmemdup(9)
• kmemdup_nul(9)
• memdup_user(9)
• vmemdup_user(9)
• strndup_user(9)
• memdup_user_nul(9)
• randomize_page(9)
• __account_locked_vm(9)
• account_locked_vm(9)
• __vmalloc_array(9)
• vmalloc_array(9)
• vcalloc(9)
• folio_mapping(9)
• folio_copy(9)
• get_cmdline(9)
• mem_dump_obj(9)
• compat_set_desc_from_vma(9)
• __compat_vma_mmap(9)
• compat_vma_mmap(9)
• snapshot_page(9)
• mmap_action_prepare(9)
• mmap_action_complete(9)
• folio_pte_batch(9)
• page_range_contiguous(9)

that's thirty-one entries, bestie. i counted. go read them all, i believe in you 😭💜

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and that's the whole page! tail end of it says it comes from ./mm and it's dated October 2026 — so mark your calendar, put it in your planner, this doc is a lil time traveler 🧚⭐ bye bestie, go zero some memory responsibly 🎀