70c60c089f
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 <gabriel@kerneis.info>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Gabriel Kerneis <gabriel@kerneis.info>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Read the documentation in qemu-doc.html or on http://wiki.qemu.org - QEMU team