From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:44613) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RLet2-0001mU-Gg for qemu-devel@nongnu.org; Wed, 02 Nov 2011 13:46:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RLet1-0001aS-El for qemu-devel@nongnu.org; Wed, 02 Nov 2011 13:46:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38068) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RLet1-0001Zv-0Q for qemu-devel@nongnu.org; Wed, 02 Nov 2011 13:46:03 -0400 Message-ID: <4EB181C4.1090501@redhat.com> Date: Wed, 02 Nov 2011 18:45:40 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <4EB1640F.2090604@adacore.com> <4EB1796B.7050901@adacore.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] Multiple instances of Qemu on Windows multicore List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: malc Cc: qemu-devel@nongnu.org, Fabien Chouteau On 11/02/2011 06:16 PM, malc wrote: > (mm)Timers have a possibility of running on a thread of their own which > might be schedulled on the CPU different from the thread that runs > emulated code, unchaining TBs and can (and will) fail in this case. This should not be a problem with dynticks+iothread (i.e. it should work or not work equally). We now run just this basically when an alarm fires: t->expired = t->pending = 1; qemu_notify_event(); The rest is always done in the iothread. The iothread will then suspend/resume the VCPU thread around the unchaining, so what matters is (in Unix parlance) signal-safety of the unchaining, not thread-safety. Paolo