Update: a third occurrence of this crash happened a few hours after filing (2026-06-14 19:14:25, signal 6 in gnome-shell, same as before). This one provides much tighter evidence about the trigger:
Memory monitoring (~30s resolution) shows the same "Shmem spike" pattern I'd previously seen 30 minutes before occurrence 1, but this time happening twice within about 90 seconds and immediately preceding the crash: - 19:12:59 — Shmem jumped from ~550MB to ~12GB in 30s. - 19:13:35 — kernel OOM killed a Spotify process (this is expected/intentional on my system due to a snap memory quota I set on Spotify to make it the preferred OOM victim). - Shmem briefly collapsed, then at 19:14:29 it spiked again to ~24GB. - 19:14:25 — kernel OOM killed two Firefox "Web Content" (content process) instances, and gnome-shell's SIGABRT crash timestamp is the *same second* (19:14:25) — versus a ~30 minute lag in occurrence 1. I'd previously suspected Spotify's on-disk cache size (22GB) was related to the Shmem spike size, and cleared it (down to 53MB). It has only regrown to ~2.1GB since, yet the same multi-GB Shmem-spike pattern recurred — so the disk cache size doesn't appear to be the actual source. Spotify is just the OOM-preferred victim due to my quota config, unrelated to the Shmem growth itself. Given `/proc/meminfo` Shmem includes GPU/DRM GEM shmem-backed buffer objects, my current working theory is that a burst of GPU buffer allocations (multi-GB, within ~30s) is the proximate trigger for the gallium driver's fence/buffer-swap abort (`dri_create_fence_fd` / `cogl_onscreen_swap_buffers_with_damage`). I haven't yet identified which process/subsystem is responsible for the buffer burst itself — planning to add finer-grained (1-2s) monitoring of per-process DRM memory via `/proc/*/fdinfo` to try to catch it in the act. Will update if I find more. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2156739 Title: gnome-shell crashes with SIGABRT in dri_create_fence_fd() (mesa- libgallium 25.2.8) on Arrow Lake-U / Xe2 iGPU during cogl_onscreen_swap_buffers_with_damage To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mesa/+bug/2156739/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
