On Mon, Jun 30, 2014 at 4:08 PM, Stefan Hajnoczi <stefa...@redhat.com> wrote: > > Try: > $ perf record -e syscalls:* --tid <iothread-tid> > ^C > $ perf script # shows the trace log > > The difference between syscalls in QEMU 2.0 and qemu.git/master could > reveal the problem.
The difference is that there are tons of write() and rt_sigprocmask() in qemu.git/master, I guess it is related coroutinue. For linux-aio, the coroutinue shouldn't be necessary because io_submit() won't block at most of times for O_DIRECT read/write. Thanks, -- Ming Lei
