From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:46241) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h1V9M-0008Ow-Uj for qemu-devel@nongnu.org; Wed, 06 Mar 2019 06:55:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1h1V9K-0005mJ-UY for qemu-devel@nongnu.org; Wed, 06 Mar 2019 06:55:52 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41104) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1h1V9H-0005jW-DZ for qemu-devel@nongnu.org; Wed, 06 Mar 2019 06:55:50 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C3C94307E040 for ; Wed, 6 Mar 2019 11:55:45 +0000 (UTC) From: Peter Xu Date: Wed, 6 Mar 2019 19:55:27 +0800 Message-Id: <20190306115532.23025-1-peterx@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH v2 0/5] iothread: create gcontext unconditionally List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Eric Blake , Stefan Hajnoczi , peterx@redhat.com, Paolo Bonzini v2: - add comment in patch 4 - add another patch to comment why we need explicit aio_poll() in iothread_run loop When I first read the iothread code, the gcontext confused me for quite a while. Meanwhile, I've been tackling with some races due to this complexity as well. How much we'll pay for creating the gcontext unconditionally? Do we really need this flexibitily (or is it really a flexibility after all)? I don't see much gain of existing code, but I might be wrong. Anyway, I wrote this patchset to see how the list would think about it. This series directly originates from previous discussion with Marc-Andre where there's a slightly hacky way to try to acquire the gcontext: https://lists.gnu.org/archive/html/qemu-devel/2019-02/msg05460.html Now with this series logically above patch is not needed any more. Please read patch 4 for more information. And if this patchset can survive... how about running gcontext directly in iothread_run()? I believe there could be a bit more things to clean but I'll see. Make check passes for me. Comments welcomed. Thanks, Peter Xu (5): iothread: replace init_done_cond with a semaphore iothread: create the gcontext unconditionally iothread: create main loop unconditionally iothread: push gcontext earlier in the thread_fn iothread: document about why we need explicit aio_poll() include/sysemu/iothread.h | 5 +-- iothread.c | 91 +++++++++++++++++++-------------------- 2 files changed, 46 insertions(+), 50 deletions(-) --=20 2.17.1