VM_BLOCK_SIZE (INT)(9)

💅 vm_block_size (int)(9) 💅

okay so bestie, welcome to the Kernel API Manual — yes, that Kernel API Manual, the one with like a million amdgpu module params in it, and today we're doing exactly one (1) of them. She's small. She's specific. She slays in her own quiet way. 🎀

🌸 NAME 🌸

vm_block_size (int) — the little knob that lets you override the VM page table size, in bits. That's it. That's the whole gig. ✨

🦋 DESCRIPTION 🦋

So here's the vibe: vm_block_size (int) overrides the VM page table size in bits.

If you don't touch it? The default depends on vm_size and your hw setup — so the hardware and the size you picked are lowkey doing a collab to decide for you. 🫶

And the default value itself is -1, which means automatic for each asic — i.e. every asic gets to pick its own fave, no cap. 💅

ngl, "default is -1 (automatic for each asic)" is the entire personality of this param and honestly? iconic. don't set it unless you know why you're setting it, bestie. 🔥

👑 SEE ALSO 👑

the way this thing has ninety siblings... it's giving huge family reunion energy 😭. All of these live in the same Kernel file, ./drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c, so consider this the extended-universe reading list. Go say hi. 💖

• vramlimit (int)(9) — sibling param, same file, same energy ✨
• vis_vramlimit (int)(9) — the visible-vram cousin, we love a sequel 💅
• gartsize (uint)(9) — note the uint, not int, stay woke 🫶
• gttsize (int)(9) — back to int, we keep it fresh 🌸
• moverate (int)(9) — she moves, respectfully 🦋
• audio (int)(9) — yes there's an audio knob in here, don't ask 💀
• disp_priority (int)(9) — display priorities, very main character 😌
• hw_i2c (int)(9) — i2c but make it hardware 🎀
• pcie_gen2 (int)(9) — gen 2, the classic 🧚
• msi (int)(9) — not the motherboard brand, moving on ⭐
• svm_default_granularity (uint)(9) — a uint, and a mouthful, love that for her 💜
• lockup_timeout (string)(9) — a string bestie, she's different 🌈
• dpm (int)(9) — three letters, iconic 👑
• fw_load_type (int)(9) — firmware loading, we stan 🙈
• aspm (int)(9) — another acronym, collect them all 🍓
• runpm (int)(9) — runtime pm, she's booked and busy ✨
• ip_block_mask (uint)(9) — masking but for IP blocks, not your feelings 😭
• bapm (int)(9) — five letters of mystery 💅
• deep_color (int)(9) — deep color, deep vibes 🌸
• vm_size (int)(9) — hey bestie, this is literally the one mentioned up in DESCRIPTION, so 👀
• vm_fragment_size (int)(9) — fragments, but make it VM 🦋
• vm_fault_stop (int)(9) — stop the fault, I can't 😭
• vm_update_mode (int)(9) — mode for updating, slay 💜
• exp_hw_support (int)(9) — experimental hw support, spicy 🔥
• dc (int)(9) — just dc. two letters. no notes. 👑
• sched_jobs (int)(9) — jobs getting scheduled fr fr ⭐
• sched_hw_submission (int)(9) — hw submission, very giving 🎀
• ppfeaturemask (hexint)(9) — hexint!! rare type sighting, obsessed 🌈
• forcelongtraining (uint)(9) — long name, longer training, uint 🧚
• pcie_gen_cap (uint)(9) — caps but for pcie gen 💅
• pcie_lane_cap (uint)(9) — lane caps, the follow-up 🫶
• cg_mask (ullong)(9) — ullong type, she's extra large 😌
• pg_mask (uint)(9) — uint this time, consistency is not the vibe 🌸
• sdma_phase_quantum (uint)(9) — quantum?? in my kernel params?? 💀
• disable_cu (charp)(9) — charp type alert, we love a rarer specimen 🦋
• virtual_display (charp)(9) — another charp, they're matching ✨
• lbpw (int)(9) — four letters, zero explanation, we move 💜
• gpu_recovery (int)(9) — recovery era 🔥
• emu_mode (int)(9) — emulation mode, no cap ⭐
• ras_enable (int)(9) — enable the ras, bestie 🎀
• ras_mask (uint)(9) — and the ras mask, uint flavored 😌
• timeout_fatal_disable (bool)(9) — a bool! we love a type change 👑
• timeout_period (uint)(9) — period, both meanings 💅
• si_support (int)(9) — support for si, whatever si is to you 🌸
• cik_support (int)(9) — and cik support, the sibling 🫶
• smu_memory_pool_size (uint)(9) — pool size, uint, go off ✨
• async_gfx_ring (int)(9) — async ring, she's asynchronous and thriving 🦋
• mcbp (int)(9) — four letters again, we love a mystery 💀
• discovery (int)(9) — discovery!! how cute 🧚
• mes_log_enable (int)(9) — enable the log, we love logging 🌈
• uni_mes (int)(9) — uni mes, unbothered 😌
• noretry (int)(9) — no retry, she said what she said 💅
• force_asic_type (int)(9) — force it, queen 🔥
• use_xgmi_p2p (int)(9) — xgmi p2p, acronym soup, delicious 🍓
• sched_policy (int)(9) — policy, but scheduled ⭐
• hws_max_conc_proc (int)(9) — abbreviated to the gods 🙈
• cwsr_enable (int)(9) — enable the cwsr, slay 💜
• max_num_of_queues_per_device (int)(9) — the longest name in the group chat, respect 👑
• send_sigterm (int)(9) — sending sigterm, dramatic but valid 😭
• halt_if_hws_hang (int)(9) — halt if it hangs, fair tbh 🫶
• hws_gws_support(bool)(9) — note: no space before (bool), we keep it exactly as she came 🌸
• queue_preemption_timeout_ms (int)(9) — _ms suffix, we love units ✨
• debug_evictions(bool)(9) — also no space before (bool), consistency? never heard of her 💅
• no_system_mem_limit(bool)(9) — same deal, jammed right up against the paren 🎀
• no_queue_eviction_on_vm_fault (int)(9) — long, specific, iconic 🦋
• mtype_local (int)(9) — local mtype, keeping it local 🌈
• pcie_p2p (bool)(9) — p2p with a bool, cute ⭐
• dcfeaturemask (uint)(9) — feature mask, uint edition 💜
• dcdebugmask (uint)(9) — debug mask, the remix 😌
• abmlevel (uint)(9) — level, uint, no further questions 🍓
• damageclips (int)(9) — damage clips, she's a little edgy 🔥
• tmz (int)(9) — three letters, maximum mystery 👑
• freesync_video (uint)(9) — freesync video, uint girlie ✨
• reset_method (int)(9) — how we reset, methodically 💅
• bad_page_threshold (int) Bad page threshold is specifies the(9) — okay so the source text literally says Bad page threshold is specifies the and we are NOT fixing it, we are preserving it character for character because that's the assignment 🫶😭. grammar who? never met her.
• vcnfw_log (int)(9) — vcnfw log, say it five times fast 🌸
• sg_display (int)(9) — sg display, slay 🦋
• umsch_mm (int)(9) — umsch mm, mm hm 💜
• umsch_mm_fwlog (int)(9) — the fwlog sequel, we love a franchise ⭐
• smu_pptable_id (int)(9) — pptable id, idk but go off 🎀
• partition_mode (int)(9) — mode for partitions, main character energy 👑
• enforce_isolation (int)(9) — enforcing isolation, very boundaries 🌈
• modeset (int)(9) — modeset, the classic ✨
• seamless (int)(9) — seamless!! aesthetic 💅
• debug_mask (uint)(9) — debug mask, uint flavor 🍓
• agp (int)(9) — three letters, vintage 🧚
• wbrf (int)(9) — four letters, no further info, bye 😭
• rebar (int)(9) — rebar, not the construction kind 🔥
• user_queue (int)(9) — queue but for the user 🫶
• ptl (int)(9) — and ptl closes out the list, final girl energy 💜

💖 the sign-off 💖

that's the whole page bestie, no cap. source: ./drivers/gpu/drm/amd/amdgpu, dated October 2026, and the page itself is vm_block_size (int)(9) — go forth, override responsibly, and remember: automatic for each asic is a valid lifestyle 💅✨🎀🦋🌸🫶