From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54396) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VPQTf-0007lC-8x for qemu-devel@nongnu.org; Fri, 27 Sep 2013 01:20:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VPQTZ-0003lk-IE for qemu-devel@nongnu.org; Fri, 27 Sep 2013 01:20:31 -0400 Message-ID: <52451595.1000506@weilnetz.de> Date: Fri, 27 Sep 2013 07:20:21 +0200 From: Stefan Weil MIME-Version: 1.0 References: <1378910555-24753-1-git-send-email-stefanha@redhat.com> In-Reply-To: <1378910555-24753-1-git-send-email-stefanha@redhat.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] coroutine: add ./configure --disable-coroutine-pool List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi , qemu-devel@nongnu.org Cc: Kevin Wolf , gabriel@kerneis.info, qemu-stable 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 > Signed-off-by: Stefan Hajnoczi > --- > 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.