VM_FAULT_STOP (INT)(9)

🌸 vm_fault_stop (int) — a.k.a. section 9 of the Kernel API Manual, bestie 💅

✨ NAME ✨

vm_fault_stop (int) — the little debug knob that literally makes your GPU stop dead the second a VM fault happens, so you can actually look at it 👀

🎀 DESCRIPTION 🎀

Okay so picture this: your driver hits a VM fault. Normally it just… keeps going, and you're left doing forensic TikTok-slideshow detective work on a log file at 3am. Not with this one, bestie.

vm_fault_stop makes the thing stop on VM fault for debugging. That's the whole job. It's giving very much "pause the movie so I can scream about this scene."

Your options, no cap:

• 0 — never stop. Chill mode. This is the default: 0 (No stop). 🧘
• 1 — print the first one, then carry on. Like reading the first text in a group chat and ignoring the rest.
• 2 — always stop. Main character energy, full commitment, every single fault gets the spotlight 🔥

And yeah, in case it wasn't obvious: the default is 0 (No stop). I said it twice because it matters twice. 🫶

Lowkey if you flip this to 2 on a machine you actually care about, expect things to get real dramatic, real fast. It's a debugging setting, bestie — treat it with the respect you'd give a hot take in the group chat. 💀

🌈 SEE ALSO 🌈

So the Kernel file this lives in is ./drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c, and bestie… it has so many friends. Behold, the entire guest list (typing every single one because I would never gatekeep):

• vramlimit (int)(9)
• vis_vramlimit (int)(9)
• gartsize (uint)(9)
• gttsize (int)(9)
• moverate (int)(9)
• audio (int)(9)
• disp_priority (int)(9)
• hw_i2c (int)(9)
• pcie_gen2 (int)(9)
• msi (int)(9)
• svm_default_granularity (uint)(9)
• lockup_timeout (string)(9)
• dpm (int)(9)
• fw_load_type (int)(9)
• aspm (int)(9)
• runpm (int)(9)
• ip_block_mask (uint)(9)
• bapm (int)(9)
• deep_color (int)(9)
• vm_size (int)(9)
• vm_fragment_size (int)(9)
• vm_block_size (int)(9)
• vm_update_mode (int)(9)
• exp_hw_support (int)(9)
• dc (int)(9)
• sched_jobs (int)(9)
• sched_hw_submission (int)(9)
• ppfeaturemask (hexint)(9)
• forcelongtraining (uint)(9)
• pcie_gen_cap (uint)(9)
• pcie_lane_cap (uint)(9)
• cg_mask (ullong)(9)
• pg_mask (uint)(9)
• sdma_phase_quantum (uint)(9)
• disable_cu (charp)(9)
• virtual_display (charp)(9)
• lbpw (int)(9)
• gpu_recovery (int)(9)
• emu_mode (int)(9)
• ras_enable (int)(9)
• ras_mask (uint)(9)
• timeout_fatal_disable (bool)(9)
• timeout_period (uint)(9)
• si_support (int)(9)
• cik_support (int)(9)
• smu_memory_pool_size (uint)(9)
• async_gfx_ring (int)(9)
• mcbp (int)(9)
• discovery (int)(9)
• mes_log_enable (int)(9)
• uni_mes (int)(9)
• noretry (int)(9)
• force_asic_type (int)(9)
• use_xgmi_p2p (int)(9)
• sched_policy (int)(9)
• hws_max_conc_proc (int)(9)
• cwsr_enable (int)(9)
• max_num_of_queues_per_device (int)(9)
• send_sigterm (int)(9)
• halt_if_hws_hang (int)(9)
• hws_gws_support(bool)(9)
• queue_preemption_timeout_ms (int)(9)
• debug_evictions(bool)(9)
• no_system_mem_limit(bool)(9)
• no_queue_eviction_on_vm_fault (int)(9)
• mtype_local (int)(9)
• pcie_p2p (bool)(9)
• dcfeaturemask (uint)(9)
• dcdebugmask (uint)(9)
• abmlevel (uint)(9)
• damageclips (int)(9)
• tmz (int)(9)
• freesync_video (uint)(9)
• reset_method (int)(9)
• bad_page_threshold (int) Bad page threshold is specifies the(9)
• vcnfw_log (int)(9)
• sg_display (int)(9)
• umsch_mm (int)(9)
• umsch_mm_fwlog (int)(9)
• smu_pptable_id (int)(9)
• partition_mode (int)(9)
• enforce_isolation (int)(9)
• modeset (int)(9)
• seamless (int)(9)
• debug_mask (uint)(9)
• agp (int)(9)
• wbrf (int)(9)
• rebar (int)(9)
• user_queue (int)(9)
• ptl (int)(9)

Not me copying that bad_page_threshold line exactly as it was written, grammatical chaos and all. It's iconic. I don't make the rules, I just preserve them 💜

Okay that's the whole page, no skips, no cuts, we ate and left absolutely zero crumbs 🍓

Cute little sign-off: this one comes to you from ./drivers/gpu/drm/amd/amdgpu, dated October 2026, and its full ✨ government name ✨ is vm_fault_stop (int)(9). Go forth and debug, bestie — and maybe leave it on 0 unless you mean it 💖