[Bug 1967130] Re: rcu_sched detected stalls on CPUs/tasks
This bug is awaiting verification that the linux- nvidia-6.8/6.8.0-1006.6~22.04.2 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-jammy-linux- nvidia-6.8' to 'verification-done-jammy-linux-nvidia-6.8'. If the problem still exists, change the tag 'verification-needed-jammy-linux- nvidia-6.8' to 'verification-failed-jammy-linux-nvidia-6.8'. If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! ** Tags added: kernel-spammed-jammy-linux-nvidia-6.8-v2 verification-needed-jammy-linux-nvidia-6.8 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1967130 Title: rcu_sched detected stalls on CPUs/tasks To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-riscv/+bug/1967130/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1967130] Re: rcu_sched detected stalls on CPUs/tasks
This bug was fixed in the package linux-riscv - 5.15.0-1007.7 --- linux-riscv (5.15.0-1007.7) jammy; urgency=medium * jammy/linux-riscv: 5.15.0-1007.7 -proposed tracker (LP: #1968740) * rcu_sched detected stalls on CPUs/tasks (LP: #1967130) - [Config] Disable VMAP_STACK due to CPU stalls on EFI * Fix unmatched ASMedia ASM2824 PCIe link training (LP: #1964796) - PCI: fu740: Force 2.5GT/s for initial device probe -- Dimitri John Ledkov Tue, 12 Apr 2022 15:44:58 +0100 ** Changed in: linux-riscv (Ubuntu) Status: Fix Committed => Fix Released -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1967130 Title: rcu_sched detected stalls on CPUs/tasks To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-riscv/+bug/1967130/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1967130] Re: rcu_sched detected stalls on CPUs/tasks
** Changed in: linux-riscv (Ubuntu) Status: Triaged => Fix Committed ** Changed in: linux-riscv (Ubuntu) Assignee: (unassigned) => Dimitri John Ledkov (xnox) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1967130 Title: rcu_sched detected stalls on CPUs/tasks To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-riscv/+bug/1967130/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1967130] Re: rcu_sched detected stalls on CPUs/tasks
** Changed in: linux-riscv (Ubuntu) Milestone: None => ubuntu-22.04 ** Changed in: linux-riscv (Ubuntu) Status: New => Triaged -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1967130 Title: rcu_sched detected stalls on CPUs/tasks To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-riscv/+bug/1967130/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1967130] Re: rcu_sched detected stalls on CPUs/tasks
VMAP_STACK is new on riscv since v5.14 kernel, meaning we haven't shipped any releases on riscv with VMAP_STACK enabled. At the time when VMAP_STACK was enabled in the kernel nobody had EFI for riscv yet either. So it makes sense that this issue is being experienced by us just now, once we got all the pieces landing together. I would be in favour to disable VMAP_STACK, on riscv64 only, until we have more fixes to make it work better. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1967130 Title: rcu_sched detected stalls on CPUs/tasks To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-riscv/+bug/1967130/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1967130] Re: rcu_sched detected stalls on CPUs/tasks
The workaround built successfully in my PPA: https://launchpad.net/~alexghiti/+archive/ubuntu/riscv/+sourcepub/13413205/+listing- archive-extra I tested it successfully with the RISC-V live installer (where this problem was seen). I did not have time yet to work on the proper fix so I think we should go for this workaround: @xnox what do you think? Thanks -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1967130 Title: rcu_sched detected stalls on CPUs/tasks To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-riscv/+bug/1967130/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1967130] Re: rcu_sched detected stalls on CPUs/tasks
I have a workaround for this: UBUNTU: SAUCE: riscv: Disable VMAP_STACK since it fails with efi When VMAP_STACK is enabled, kernel threads have their stacks in the vmalloc region. So when The kworker responsible for handling efi work queue (efi_call_rts) calls efi_virtmap_load and then switch_mm, if the stack of the worker is in a vmalloc area not yet synchronized with efi_mm (since RISC-V lazily populates vmalloc area), an attempt to access this stack will trigger a fault which can't be resolved since when trying to save the context, a new trap will be triggered and so on. So disable VMAP_STACK for now until we figure out the correct fix. And I'm working on the proper fix which consists in synchronizing the efi page table with the page table of the calling thread before switching to efi mm. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1967130 Title: rcu_sched detected stalls on CPUs/tasks To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-riscv/+bug/1967130/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1967130] Re: rcu_sched detected stalls on CPUs/tasks
efi: Make efi_rts_work accessible to efi page fault handler https://lore.kernel.org/all/20200318090253.ga32...@duo.ucw.cz/T/#mcbd236122ec0ae61f1ee9c22b8d7910ffc2276a0 addressed a similar issue on x86. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1967130 Title: rcu_sched detected stalls on CPUs/tasks To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-riscv/+bug/1967130/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1967130] Re: rcu_sched detected stalls on CPUs/tasks
apport information ** Tags added: apport-collected ** Description changed: When running the riscv64 live installer (https://cdimage.ubuntu.com/ubuntu-server/daily-live/20220330/jammy- live-server-riscv64.iso) on the SiFive Unmatched board we reproducibly see rcu_sched stalls related to accessing the UEFI runtime: Mar 30 11:50:47 ubuntu-server kernel: [ 1313.451647] rcu: INFO: rcu_sched detected stalls on CPUs/tasks: Mar 30 11:50:47 ubuntu-server kernel: [ 1313.451673] rcu: 3-...0: (3 GPs behind) idle=d03/1/0x4000 softirq=85648/85648 fqs=7326 Mar 30 11:50:47 ubuntu-server kernel: [ 1313.451698](detected by 0, t=15002 jiffies, g=155853, q=1286) Mar 30 11:50:47 ubuntu-server kernel: [ 1313.451712] Task dump for CPU 3: Mar 30 11:50:47 ubuntu-server kernel: [ 1313.451720] task:kworker/u8:1 state:R running task stack:0 pid: 3715 ppid: 2 flags:0x0008 Mar 30 11:50:47 ubuntu-server kernel: [ 1313.451750] Workqueue: efi_rts_wq efi_call_rts Mar 30 11:50:47 ubuntu-server kernel: [ 1313.451777] Call Trace: Mar 30 11:50:47 ubuntu-server kernel: [ 1313.451782] [] __schedule+0x226/0x644 uname -a: Linux ubuntu-server 5.15.0-1004-generic #4-Ubuntu SMP Wed Feb 9 18:17:33 UTC 2022 riscv64 riscv64 riscv64 GNU/Linux + --- + ProblemType: Bug + Architecture: riscv64 + DistroRelease: Ubuntu 22.04 + Package: linux-image-generic 5.15.0.1004.4 + PackageArchitecture: riscv64 + ProcEnviron: + TERM=vt220 + PATH=(custom, no user) + LANG=C.UTF-8 + Uname: Linux 5.15.0-1004-generic riscv64 + UserGroups: N/A + _MarkForUpload: True ** Attachment added: "Dependencies.txt" https://bugs.launchpad.net/bugs/1967130/+attachment/5574772/+files/Dependencies.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1967130 Title: rcu_sched detected stalls on CPUs/tasks To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-riscv/+bug/1967130/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1967130] Re: rcu_sched detected stalls on CPUs/tasks
** Attachment added: "dmesg" https://bugs.launchpad.net/ubuntu/+source/linux-riscv/+bug/1967130/+attachment/5574773/+files/dmesg -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1967130 Title: rcu_sched detected stalls on CPUs/tasks To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-riscv/+bug/1967130/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
