Am 11.09.2013 16:42, schrieb Stefan Hajnoczi: > The 'gthread' coroutine backend was written before the freelist (aka > pool) existed in qemu-coroutine.c. > > This means that every thread is expected to exit when its coroutine > terminates. It is not possible to reuse threads from a pool. > > This patch automatically disables the pool when 'gthread' is used. This > allows the 'gthread' backend to work again (for example, > tests/test-coroutine completes successfully instead of hanging). > > I considered implementing thread reuse but I don't want quirks like CPU > affinity differences due to coroutine threads being recycled. The > 'gthread' backend is a reference backend and it's therefore okay to skip > the pool optimization. > > Note this patch also makes it easy to toggle the pool for benchmarking > purposes: > > ./configure --with-coroutine-backend=ucontext \ > --disable-coroutine-pool > > Reported-by: Gabriel Kerneis <gabr...@kerneis.info> > Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com> > --- > configure | 24 ++++++++++++++++++++++++ > qemu-coroutine.c | 34 +++++++++++++++++++--------------- > 2 files changed, 43 insertions(+), 15 deletions(-) >
This patch is important for QEMU 1.5 as well, but needs some modifications there. A recent bug report for MinGW shows that the win32 coroutine needs it, too. Stefan, could you please prepare a patch for stable-1.5? Regards Stefan W.
