Hi Michael! On 11/1/21 08:37, John Paul Adrian Glaubitz wrote: > I made another experiment and upgraded the host to 5.15-rc7 which contains > your > fixes and made the guests build gcc-10. Interestingly, this time, the gcc-10 > build crashed the guest but didn't manage to crash the host. I will update the > guest to 5.15-rc7 now as well and see how that goes.
OK, so I'm definitely able to crash the 5.15 kernel as well: [57031.404944] watchdog: BUG: soft lockup - CPU#24 stuck for 14957s! [migration/24:14] [57035.420898] watchdog: BUG: soft lockup - CPU#48 stuck for 14961s! [CPU 17/KVM:1815] [57047.456761] watchdog: BUG: soft lockup - CPU#152 stuck for 14841s! [CPU 13/KVM:1811] [57055.404670] watchdog: BUG: soft lockup - CPU#24 stuck for 14979s! [migration/24:14] [57059.420624] watchdog: BUG: soft lockup - CPU#48 stuck for 14983s! [CPU 17/KVM:1815] [57064.064573] rcu: INFO: rcu_sched self-detected stall on CPU [57064.064584] rcu: 48-....: (3338577 ticks this GP) idle=9f3/1/0x4000000000000002 softirq=77540/77540 fqs=15421 [57064.064598] rcu: rcu_sched kthread timer wakeup didn't happen for 3988041 jiffies! g125265 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200 [57064.064606] rcu: Possible timer handling issue on cpu=136 timer-softirq=313650 [57064.064611] rcu: rcu_sched kthread starved for 3988042 jiffies! g125265 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200 ->cpu=136 [57064.064618] rcu: Unless rcu_sched kthread gets sufficient CPU time, OOM is now expected behavior. [57064.064624] rcu: RCU grace-period kthread stack dump: [57064.064665] rcu: Stack dump where RCU GP kthread last ran: [57071.456487] watchdog: BUG: soft lockup - CPU#152 stuck for 14863s! [CPU 13/KVM:1811] [57079.404396] watchdog: BUG: soft lockup - CPU#24 stuck for 15002s! [migration/24:14] And the gcc-10 testsuite is able to trigger the crash very reliably. Adrian -- .''`. John Paul Adrian Glaubitz : :' : Debian Developer - glaub...@debian.org `. `' Freie Universitaet Berlin - glaub...@physik.fu-berlin.de `- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913
