From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:43705) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UPbE7-0005Xn-JS for qemu-devel@nongnu.org; Tue, 09 Apr 2013 12:16:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UPbE6-0007Sv-2Y for qemu-devel@nongnu.org; Tue, 09 Apr 2013 12:16:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40133) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UPbE5-0007RJ-QB for qemu-devel@nongnu.org; Tue, 09 Apr 2013 12:16:53 -0400 Message-ID: <51643EE9.5010300@redhat.com> Date: Tue, 09 Apr 2013 18:16:41 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1365523615-5177-1-git-send-email-chouteau@adacore.com> In-Reply-To: <1365523615-5177-1-git-send-email-chouteau@adacore.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 0/3] Release SMP restriction on Windows host List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fabien Chouteau Cc: hainque@adacore.com, peter.maydell@linaro.org, sw@weilnetz.de, qemu-devel@nongnu.org, blauwirbel@gmail.com, afaerber@suse.de Il 09/04/2013 18:06, Fabien Chouteau ha scritto: > As I already explained to this mailling list, we (AdaCore) use QEMU to run a > lot of short executable (~2 secs) on many different targets. In that > configuration the SMP restriction on Windows (QEMU runs only on 1 core) was not > efficient on our 16 cores servers. > > Few months ago I asked on this mailing list if the restriction could be > removed. There was no clear answer because nobody was able to tell if it would > work. We decided to give it a try. > > During the last months we only found one problem, it was a dead lock between > the TCG and IO thread, this is fixed by the second patch. > > We also found that suspendThread() and resumeThread() were not synchronous on > SMP systems, so we added a busy loop to wait for effective suspension. > > Since then, we run thousands of QEMU on our SMP Windows servers each day > without any problem. And of course we greatly improve the execution time of our > test-suites. Awesome! Thanks guys. Reviewed-by: Paolo Bonzini Paolo