On 10/07/2014 02:17 PM, Joel Schopp wrote: > On 10/07/2014 01:34 PM, Christoffer Dall wrote: >> On Tue, Oct 07, 2014 at 01:28:38PM -0500, Joel Schopp wrote: >>>>> -drive file=/Image.img,id=fs -device virtio-blk-device,drive=fs >>>>> >>>>> more specifically >>>>> ./aarch64-softmmu/qemu-system-aarch64 -smp 1 --enable-kvm -nographic >>>>> -kernel /Image -drive file=/Image.img,id=fs -device >>>>> virtio-blk-device,drive=fs -m 1024 -M virt -cpu host -no-reboot -append >>>>> "console=ttyAMA0 console=ttyS0 rootwait root=/dev/vda4 rw" >>>>> >>>> Can you post your guest kernel config somewhere for me to try and >>>> reproduce? >>> Thanks for offering to help. Before you spend some time on it let me >>> debug and see what progress I can make. Since I can reproduce it >>> reliably now I can narrow things down with git bisect. Traced it back to the introduction of NO_HZ. Going from CONFIG_HZ_PERIODIC to CONFIG_NO_HZ_IDLE or CONFIG_NO_HZ_FULL is enough to do it. Earlier in boot there was a message that might be related: drivers/rtc/hctosys.c: unable to open rtc device (rtc0) And indeed there is not rtc or rtc0 in /dev in the guest like there is on the host. I'm guessing this is more missing functionality than it is a bug. --- ../goodconfig 2014-10-07 01:05:56.772530930 -0400 +++ ../stilstilbroken 2014-10-07 01:30:39.183447517 -0400 @@ -64,8 +64,9 @@ # Timers subsystem # CONFIG_TICK_ONESHOT=y -CONFIG_HZ_PERIODIC=y -# CONFIG_NO_HZ_IDLE is not set +CONFIG_NO_HZ_COMMON=y +# CONFIG_HZ_PERIODIC is not set +CONFIG_NO_HZ_IDLE=y # CONFIG_NO_HZ_FULL is not set # CONFIG_NO_HZ is not set CONFIG_HIGH_RES_TIMERS=y @@ -73,8 +74,9 @@ # # CPU/Task time and stats accounting # -CONFIG_TICK_CPU_ACCOUNTING=y -# CONFIG_VIRT_CPU_ACCOUNTING_GEN is not set +CONFIG_VIRT_CPU_ACCOUNTING=y +# CONFIG_TICK_CPU_ACCOUNTING is not set +CONFIG_VIRT_CPU_ACCOUNTING_GEN=y # CONFIG_BSD_PROCESS_ACCT is not set # CONFIG_TASKSTATS is not set @@ -84,10 +86,13 @@ CONFIG_TREE_RCU=y # CONFIG_PREEMPT_RCU is not set CONFIG_RCU_STALL_COMMON=y -# CONFIG_RCU_USER_QS is not set +CONFIG_CONTEXT_TRACKING=y +CONFIG_RCU_USER_QS=y +# CONFIG_CONTEXT_TRACKING_FORCE is not set CONFIG_RCU_FANOUT=64 CONFIG_RCU_FANOUT_LEAF=16 # CONFIG_RCU_FANOUT_EXACT is not set +# CONFIG_RCU_FAST_NO_HZ is not set # CONFIG_TREE_RCU_TRACE is not set CONFIG_RCU_NOCB_CPU=y # CONFIG_RCU_NOCB_CPU_NONE is not set _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
