From ba20326a937421c50a775907dc9ac726bb9a9b50 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 11 Sep 2013 16:42:35 +0200 Subject: coroutine: add ./configure --disable-coroutine-pool 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 Signed-off-by: Stefan Hajnoczi Reviewed-by: Gabriel Kerneis Signed-off-by: Kevin Wolf (cherry picked from commit 70c60c089fdc6bf8a79324e492c13e8c08d55942) Signed-off-by: Michael Roth --- configure | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'configure') diff --git a/configure b/configure index 18fa60824b..4cf672d0c6 100755 --- a/configure +++ b/configure @@ -235,6 +235,7 @@ guest_agent="" want_tools="yes" libiscsi="" coroutine="" +coroutine_pool="" seccomp="" glusterfs="" glusterfs_discard="no" @@ -871,6 +872,10 @@ for opt do ;; --with-coroutine=*) coroutine="$optarg" ;; + --disable-coroutine-pool) coroutine_pool="no" + ;; + --enable-coroutine-pool) coroutine_pool="yes" + ;; --disable-docs) docs="no" ;; --enable-docs) docs="yes" @@ -1152,6 +1157,8 @@ echo " --disable-seccomp disable seccomp support" echo " --enable-seccomp enables seccomp support" echo " --with-coroutine=BACKEND coroutine backend. Supported options:" echo " gthread, ucontext, sigaltstack, windows" +echo " --disable-coroutine-pool disable coroutine freelist (worse performance)" +echo " --enable-coroutine-pool enable coroutine freelist (better performance)" echo " --enable-glusterfs enable GlusterFS backend" echo " --disable-glusterfs disable GlusterFS backend" echo " --enable-gcov enable test coverage analysis with gcov" @@ -3240,6 +3247,17 @@ else esac fi +if test "$coroutine_pool" = ""; then + if test "$coroutine" = "gthread"; then + coroutine_pool=no + else + coroutine_pool=yes + fi +fi +if test "$coroutine" = "gthread" -a "$coroutine_pool" = "yes"; then + error_exit "'gthread' coroutine backend does not support pool (use --disable-coroutine-pool)" +fi + ########################################## # check if we have open_by_handle_at @@ -3605,6 +3623,7 @@ echo "libiscsi support $libiscsi" echo "build guest agent $guest_agent" echo "seccomp support $seccomp" echo "coroutine backend $coroutine" +echo "coroutine pool $coroutine_pool" echo "GlusterFS support $glusterfs" echo "virtio-blk-data-plane $virtio_blk_data_plane" echo "gcov $gcov_tool" @@ -3954,6 +3973,11 @@ if test "$rbd" = "yes" ; then fi echo "CONFIG_COROUTINE_BACKEND=$coroutine" >> $config_host_mak +if test "$coroutine_pool" = "yes" ; then + echo "CONFIG_COROUTINE_POOL=1" >> $config_host_mak +else + echo "CONFIG_COROUTINE_POOL=0" >> $config_host_mak +fi if test "$open_by_handle_at" = "yes" ; then echo "CONFIG_OPEN_BY_HANDLE=y" >> $config_host_mak -- cgit v1.2.3