Comment # 2 on bug 995260 from zhen ren

Today, I ran 4 rounds of this testcase and they all passed. So, I'm thinking
maybe it's the CPU scheduler problem on KVM cluster, which is also happened for
corosync... 

jbd2 is always the first to report hung warning; we can see this 2 lines
(reverse order):

kernel: [<ffffffff81704cac>] schedule+0x3c/0x90
kernel: [<ffffffff813053f0>] jbd2_journal_commit_transaction+0x250/0x1920

In what situation, jbd2_journal_commit_transaction() will give up the cpu by
schedule(), and never get scheduled from then? Oh, it sounds crazy... 

Anyway, i'd like keep this low priority so far, and look into further