| Summary: | AB-INT: qemu central error: drm_crtc_wait_one_vblank | ||||||
|---|---|---|---|---|---|---|---|
| Product: | [QA/Testing] Runtime Testing | Reporter: | Mathieu Dubois-Briand <mathieu.dubois-briand> | ||||
| Component: | general | Assignee: | Unassigned <unassigned> | ||||
| Status: | RESOLVED FIXED | QA Contact: | |||||
| Severity: | normal | ||||||
| Priority: | Undecided | CC: | david.c.nystrom, richard.purdie | ||||
| Version: | unspecified | ||||||
| Target Milestone: | 0.0.0 | ||||||
| Hardware: | x86 | ||||||
| OS: | Multiple | ||||||
| Whiteboard: | AB-INT | ||||||
| OS type for building Yocto: | --- | Type of Regression: | --- | ||||
| Verified: | Documentation change: | Don't know | |||||
| Attachments: |
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qemux86-64-ptest alma8-vk-2 master completed at 2026-09-11 01:34:49+00:00 https://valkyrie.yocto.io/pub/non-release/20260911-8/testresults/qemux86-64-ptest/ https://autobuilder.yoctoproject.org/valkyrie/#/builders/73/builds/4538/steps/16/logs/stdio no-x11 debian11-vk-1 master completed at 2026-09-04 17:57:58+00:00 https://autobuilder.yoctoproject.org/valkyrie/#/builders/25/builds/4577/steps/16/logs/stdio Normally, a WARN on caused by excessive CPU load is a CVE, due to PANIC_ON_WARN. The DRM subsystem does not agree to above(for emulators), and patching this upstream seems unlikely, discussed here: https://lore.kernel.org/lkml/0000000000009cd8d505bd545452@google.com/T/#m12dc6602275a453d674588dd9c95e7d147b72ff3 And referenced in commit: https://lore.kernel.org/all/2dae83e3-6fee-4e66-964e-c7baf46eecd8@suse.de/ I somewhat suspect this is due to parallel QEMU runs on the same build machine. 1. Reduce load on machines running QEMU. (sequential runs ?) 2. Is emulating a display essential for the testcases running ? Ah, v6.19 introduced vblank usage in the bochs driver in commit: bde44378397b1969f2be5908f41083e900eb5294 drm/bochs: Use vblank timer Thats likely why we did not see this on v6.18. We could attempt to revert it for some time. But I guess its worth brinding this up upstream. Seems like a strange thing to do for a driver which is emulator only. Filter the WARN, or revert the commit ? Demoting from WARN to something else was rejected here. We could try again, since syzbot seems to have similiar issues. https://lore.kernel.org/all/20251003032303.16518-1-chintanlike@gmail.com/T/#m5490443bd3053462cb640fef405a93356f2fb30d Unassigning, since Bruce found a proper fix. https://lore.kernel.org/all/20260917051340.1472139-5-bruce.ashfield@gmail.com/ |
Created attachment 5245 [details] dmesg full log I'm not sure what the issue is here, as we are only seeing a warning in kernel logs. AssertionError: 6 != 0 : Log: /srv/pokybuild/yocto-worker/qemux86-64-ptest/build/build/tmp/work/qemux86_64-poky-linux/core-image-ptest-openssh/1.0/target_logs/dmesg_output.log ----------------------- Central error: [ 3.266523] ------------[ cut here ]------------ *********************** [ 1.372278] Freeing unused kernel image (text/rodata gap) memory: 756K [ 1.374059] Freeing unused kernel image (rodata/data gap) memory: 1596K [ 1.375722] Run /sbin/init as init process [ 1.376759] with arguments: [ 1.376760] /sbin/init [ 1.376760] with environment: [ 1.376761] HOME=/ [ 1.376761] TERM=linux [ 2.204050] udevd[142]: starting version 3.2.14 [ 2.207411] udevd[143]: starting eudev-3.2.14 [ 3.266523] ------------[ cut here ]------------ [ 3.268078] bochs-drm 0000:00:01.0: [drm] vblank wait timed out on crtc 0 [ 3.270141] WARNING: /usr/src/kernel/drivers/gpu/drm/drm_vblank.c:1329 at drm_crtc_wait_one_vblank+0x1a5/0x230, CPU#0: kworker/0:1/10 [ 3.273746] Modules linked in: [ 3.274709] CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted 7.2.4-yocto-standard #1 PREEMPT(full) [ 3.277498] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 [ 3.280841] Workqueue: events drm_fb_helper_damage_work [ 3.282431] RIP: 0010:drm_crtc_wait_one_vblank+0x1ae/0x230 [ 3.284085] Code: e8 37 1e 07 00 48 8b 7b 08 4c 8b 67 50 4d 85 e4 75 03 4c 8b 27 e8 22 1e 07 00 48 8d 3d 1b 95 2c 01 44 89 e9 4c 89 e2 48 89 c6 <67> 48 0f b9 3a 44 89 ee 48 89 df 41 be 92 ff ff ff e8 7c fc ff ff [ 3.289540] RSP: 0018:ffffa85a8005bd08 EFLAGS: 00010286 [ 3.291108] RAX: ffffffff86b95de4 RBX: ffff9797c18f6000 RCX: 0000000000000000