diff options
Diffstat (limited to 'results/classifier/mode-deepseek-r1:32b/reasoning/system/2634')
| -rw-r--r-- | results/classifier/mode-deepseek-r1:32b/reasoning/system/2634 | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/results/classifier/mode-deepseek-r1:32b/reasoning/system/2634 b/results/classifier/mode-deepseek-r1:32b/reasoning/system/2634 new file mode 100644 index 00000000..e91c0fec --- /dev/null +++ b/results/classifier/mode-deepseek-r1:32b/reasoning/system/2634 @@ -0,0 +1,19 @@ +<think> +Okay, so I'm looking at this problem where QEMU's record/replay feature isn't working properly when using snapshots, specifically with `rrsnapshot` or `loadvm`. The user provided a detailed report with commands and outputs. + +First, let me understand the setup. They're using Alpine Linux as the guest OS, running on an x86_64 machine. They've set up QEMU with certain configurations, including `-cpu SandyBridge`, serial console, no display, 4GB RAM, etc. The issue arises when they try to use `rrsnapshot=init` during replay; the VM gets stuck at boot. + +From the logs, when they record without snapshots, it works fine, but adding `rrsnapshot` causes problems. They also tried using `loadvm init` via the monitor and encountered similar issues. Debugging shows a thread stuck in `rcu.c`, specifically waiting on `qemu_event_wait(&rcu_call_ready_event);`. That suggests some kind of synchronization issue or deadlock. + +I know that QEMU's record/replay uses the RCU (Read-Copy-Update) mechanism for handling certain data structures. RCU is used in the context of asynchronous operations, and if something goes wrong during a replay with snapshots, it could cause threads to hang while waiting for an event that never comes. + +Now, thinking about whether this is a user-mode or system-mode issue. User-mode issues typically involve problems within the guest OS or how the application interacts with QEMU. System-mode issues are more about hardware emulation, device drivers, or lower-level processes handled by QEMU itself. + +In this case, the problem seems to be occurring within QEMU's own mechanisms, specifically in `rcu.c`, which is part of the core infrastructure for handling concurrent operations. The fact that the VM gets stuck indicates a deeper issue with how QEMU manages its internal state during replay with snapshots. This isn't something that would typically be caused by userland applications or guest OS behavior but rather how QEMU handles its own threads and synchronization. + +Moreover, when using `loadvm`, it's an internal command to restore the VM's state from a snapshot. If this is causing issues, it points towards a problem in how QEMU saves or restores that state, possibly interacting with RCU in a way that leaves certain events pending indefinitely. + +So, putting it all together, this seems like a system-mode issue because it's related to QEMU's internal handling of VM states and concurrency mechanisms, which are part of the lower-level infrastructure required for accurate record and replay, especially when snapshots are involved. It doesn't appear to be an application-level problem but rather a bug in QEMU's implementation. +</think> + +system \ No newline at end of file |