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09000adb86
Following dump is observed on host when clearing the exit timing counters
[root@p1021mds kvm]# echo -n 'c' > vm1200_vcpu0_timing
INFO: task echo:1276 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
echo D 0ff5bf94 0 1276 1190 0x00000000
Call Trace:
[c2157e40] [c0007908] __switch_to+0x9c/0xc4
[c2157e50] [c040293c] schedule+0x1b4/0x3bc
[c2157e90] [c04032dc] __mutex_lock_slowpath+0x74/0xc0
[c2157ec0] [c00369e4] kvmppc_init_timing_stats+0x20/0xb8
[c2157ed0] [c0036b00] kvmppc_exit_timing_write+0x84/0x98
[c2157ef0] [c00b9f90] vfs_write+0xc0/0x16c
[c2157f10] [c00ba284] sys_write+0x4c/0x90
[c2157f40] [c000e320] ret_from_syscall+0x0/0x3c
The vcpu->mutex is used by kvm_ioctl_* (KVM_RUN etc) and same was
used when clearing the stats (in kvmppc_init_timing_stats()). What happens
is that when the guest is idle then it held the vcpu->mutx. While the
exiting timing process waits for guest to release the vcpu->mutex and
a hang state is reached.
Now using seprate lock for exit timing stats.
Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
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| .. | ||
| 44x_emulate.c | ||
| 44x_tlb.c | ||
| 44x_tlb.h | ||
| 44x.c | ||
| book3s_32_mmu_host.c | ||
| book3s_32_mmu.c | ||
| book3s_32_sr.S | ||
| book3s_64_mmu_host.c | ||
| book3s_64_mmu.c | ||
| book3s_64_slb.S | ||
| book3s_emulate.c | ||
| book3s_exports.c | ||
| book3s_interrupts.S | ||
| book3s_mmu_hpte.c | ||
| book3s_paired_singles.c | ||
| book3s_rmhandlers.S | ||
| book3s_segment.S | ||
| book3s.c | ||
| booke_emulate.c | ||
| booke_interrupts.S | ||
| booke.c | ||
| booke.h | ||
| e500_emulate.c | ||
| e500_tlb.c | ||
| e500_tlb.h | ||
| e500.c | ||
| emulate.c | ||
| fpu.S | ||
| Kconfig | ||
| Makefile | ||
| powerpc.c | ||
| timing.c | ||
| timing.h | ||
| trace.h | ||