You are absolute right and this solved the puzzle. I also did
profiling to confirm your observation. Thank you for all the help!
> Hi again, I took another look at qemu-kvm 0.12.3 and here is how I read it:
>
> The mutex which is supposed to protect IO emulation is qemu-kvm.c:qemu_mutex.
>
> The c
Hi there,
I am reading the snapshot source code of qemu-kvm-0.12.3, and am
puzzled by the thread synchronization issue in qcow2.c and
qcow2-cluster.c. Could someone please enlighten me? Thanks!
Specifically, I found that BDRVQcowState.cluster_allocs, which is a
QLIST_HEAD, may be accessed concurr