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<p>[sorry, I hit send too early]</p>
<p><br>
</p>
On 2023-10-23 11:15, Christian König wrote:<br>
<blockquote type="cite">Am 23.10.23 um 15:06 schrieb Daniel Tang:<br>
<blockquote type="cite">That commit causes the screen to freeze a
few moments after running<br>
clinfo on v6.6-rc7 and ROCm 5.6. Sometimes the rest of the
computer<br>
including ssh also freezes. On v6.5-rc1, it only results in a
NULL pointer<br>
deference message in dmesg and the process to become a zombie
whose<br>
unkillableness prevents shutdown without REISUB. Although
llama.cpp and<br>
hashcat were working in v6.2 and ROCm 5.6, broke, and are not
fixed by<br>
this revert, pytorch-rocm is now working with stability and
without<br>
whole-computer freezes caused by any accidental running of
clinfo.<br>
<br>
This reverts commit 1d7776cc148b9f2f3ebaf1181662ba695a29f639.<br>
</blockquote>
<br>
That result doesn't make much sense. Felix please correct me, but
AFAIK the ATS stuff was completely removed by now.<br>
<br>
Are you sure that this is pure v6.6-rc7 and not some other patches
applied? If yes than we must have missed something.<br>
</blockquote>
<br>
This revert doesn't really affect systems with ATS. It moves the
sanity check back out of the ATS-specific code.<br>
<br>
The Null pointer dereference in the bug report comes from the CPU
page table update code:<br>
<pre>[10089.267556] BUG: kernel NULL pointer dereference, address: 0000000000000000
[10089.267563] #PF: supervisor write access in kernel mode
[10089.267566] #PF: error_code(0x0002) - not-present page
[10089.267569] PGD 0 P4D 0
[10089.267574] Oops: 0002 [#1] PREEMPT SMP NOPTI
[10089.267578] CPU: 23 PID: 18191 Comm: clinfo Tainted: G OE 6.5.0-9-generic #9-Ubuntu
[10089.267582] Hardware name: Micro-Star International Co., Ltd. MS-7C37/X570-A PRO (MS-7C37), BIOS H.I0 08/10/2022
[10089.267585] RIP: 0010:amdgpu_gmc_set_pte_pde+0x23/0x40 [amdgpu]
[10089.267820] Code: 90 90 90 90 90 90 90 0f 1f 44 00 00 48 b8 00 f0 ff ff ff ff 00 00 55 48 21 c1 8d 04 d5 00 00 00 00 4c 09 c1 48 01 c6 48 89 e5 <48> 89 0e 31 c0 5d 31 d2 31 c9 31 f6 45 31 c0 e9 89 7e 27 fb 66 0f
[10089.267823] RSP: 0018:ffffb49805eeb8b0 EFLAGS: 00010246
[10089.267827] RAX: 0000000000000000 RBX: 0000000000200000 RCX: 0040000000000480
[10089.267830] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9890d4380000
[10089.267832] RBP: ffffb49805eeb8b0 R08: 0040000000000480 R09: 0000000000200000
[10089.267835] R10: 0000000800100200 R11: 0000000800100200 R12: ffffb49805eeba98
[10089.267837] R13: 0000000000000001 R14: 0000000000200000 R15: 0000000000000001
[10089.267840] FS: 00007f8ca9f09740(0000) GS:ffff9897befc0000(0000) knlGS:0000000000000000
[10089.267843] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[10089.267846] CR2: 0000000000000000 CR3: 00000002e0746000 CR4: 0000000000750ee0
[10089.267849] PKRU: 55555554
[10089.267851] Call Trace:
[10089.267853] <TASK>
[10089.267858] ? show_regs+0x6d/0x80
[10089.267865] ? __die+0x24/0x80
[10089.267870] ? page_fault_oops+0x99/0x1b0
[10089.267876] ? do_user_addr_fault+0x316/0x6b0
[10089.267879] ? srso_alias_return_thunk+0x5/0x7f
[10089.267884] ? scsi_dispatch_cmd+0x91/0x240
[10089.267891] ? exc_page_fault+0x83/0x1b0
[10089.267896] ? asm_exc_page_fault+0x27/0x30
[10089.267904] ? amdgpu_gmc_set_pte_pde+0x23/0x40 [amdgpu]
[10089.268140] amdgpu_vm_cpu_update+0xa9/0x130 [amdgpu]
...
</pre>
This revert is just a roundabout way of disabling CPU page table
updates for compute VMs. But I don't think it really addresses the
root cause.<br>
<br>
Regards,<br>
Felix
<p><br>
</p>
<blockquote type="cite"><br>
Regards,<br>
Christian.<br>
<br>
<blockquote type="cite"><br>
Closes: <a class="moz-txt-link-freetext" href="https://github.com/RadeonOpenCompute/ROCm/issues/2596">https://github.com/RadeonOpenCompute/ROCm/issues/2596</a><br>
Signed-off-by: Daniel Tang
<a class="moz-txt-link-rfc2396E" href="mailto:danielzgtg.opensource@gmail.com"><danielzgtg.opensource@gmail.com></a><br>
---<br>
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 12 ++++++------<br>
1 file changed, 6 insertions(+), 6 deletions(-)<br>
<br>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c<br>
index 82f25996ff5e..602f311ab766 100644<br>
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c<br>
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c<br>
@@ -2243,16 +2243,16 @@ int amdgpu_vm_make_compute(struct
amdgpu_device *adev, struct amdgpu_vm *vm)<br>
if (r)<br>
return r;<br>
+ /* Sanity checks */<br>
+ if (!amdgpu_vm_pt_is_root_clean(adev, vm)) {<br>
+ r = -EINVAL;<br>
+ goto unreserve_bo;<br>
+ }<br>
+<br>
/* Check if PD needs to be reinitialized and do it before<br>
* changing any other state, in case it fails.<br>
*/<br>
if (pte_support_ats != vm->pte_support_ats) {<br>
- /* Sanity checks */<br>
- if (!amdgpu_vm_pt_is_root_clean(adev, vm)) {<br>
- r = -EINVAL;<br>
- goto unreserve_bo;<br>
- }<br>
-<br>
vm->pte_support_ats = pte_support_ats;<br>
r = amdgpu_vm_pt_clear(adev, vm,
to_amdgpu_bo_vm(vm->root.bo),<br>
false);<br>
-- 2.40.1<br>
<br>
<br>
<br>
</blockquote>
<br>
</blockquote>
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