From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54114) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZHF9l-0005D8-Bm for qemu-devel@nongnu.org; Mon, 20 Jul 2015 13:47:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZHF9f-00010X-EJ for qemu-devel@nongnu.org; Mon, 20 Jul 2015 13:47:13 -0400 Received: from greensocs.com ([193.104.36.180]:54723) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZHF9e-0000yP-Jc for qemu-devel@nongnu.org; Mon, 20 Jul 2015 13:47:07 -0400 Message-ID: <55AD3413.6060304@greensocs.com> Date: Mon, 20 Jul 2015 19:46:59 +0200 From: Frederic Konrad MIME-Version: 1.0 References: <1437144337-21442-1-git-send-email-fred.konrad@greensocs.com> <87fv4iu3xt.fsf@linaro.org> In-Reply-To: <87fv4iu3xt.fsf@linaro.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [RFC PATCH V3 0/3] Multithread TCG async_safe_work part. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?UTF-8?B?QWxleCBCZW5uw6ll?= Cc: mttcg@listserver.greensocs.com, mark.burton@greensocs.com, qemu-devel@nongnu.org, a.rigo@virtualopensystems.com, guillaume.delbergue@greensocs.com, pbonzini@redhat.com On 20/07/2015 19:36, Alex Benn=C3=A9e wrote: > fred.konrad@greensocs.com writes: > >> From: KONRAD Frederic >> >> This is the async_safe_work introduction bit of the Multithread TCG wo= rk. >> Rebased on current upstream (6169b60285fe1ff730d840a49527e721bfb30899)= . >> >> (Currently untested as I need to rebase MTTCG first.) >> >> It can be cloned here: >> http://git.greensocs.com/fkonrad/mttcg.git branch async_work_v3 >> >> The first patch introduces a mutex to protect the existing queued_work= _* >> CPUState members against multiple (concurent) access. >> >> The second patch introduces a tcg_exec_flag which will be 1 when we ar= e inside >> cpu_exec(), -1 when we must not enter the cpu execution and 0 when we = are >> allowed to do so. This is required as safe work need to be sure that's= all vCPU >> are outside cpu_exec(). >> >> The last patch introduces async_safe_work. It allows to add some work = which will >> be done asynchronously but only when all vCPUs are outside cpu_exec().= The tcg >> thread will wait that no vCPUs have any pending safe work before reent= ering >> cpu-exec(). >> >> Changes V2 -> V3: >> * Check atomically we are not in the executiong loop to fix the rac= e condition >> which might happen. >> Changes V1 -> V2: >> * Release the lock while running the callback for both async and sa= fe work. >> >> KONRAD Frederic (3): >> cpus: protect queued_work_* with work_mutex. >> cpus: add tcg_exec_flag. >> cpus: introduce async_run_safe_work_on_cpu. > Also currently breaks a lot of targets: > > https://travis-ci.org/stsquad/qemu/builds/71797143 oops yes, seems linux-user is not happy at all. Will fix that. Thanks, Fred >> cpu-exec.c | 10 ++++ >> cpus.c | 160 ++++++++++++++++++++++++++++++++++++++++----= ---------- >> include/qom/cpu.h | 57 +++++++++++++++++++ >> qom/cpu.c | 20 +++++++ >> 4 files changed, 207 insertions(+), 40 deletions(-)