From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NILgw-0007OE-Ov for qemu-devel@nongnu.org; Wed, 09 Dec 2009 07:30:50 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NILgs-0007LE-1l for qemu-devel@nongnu.org; Wed, 09 Dec 2009 07:30:50 -0500 Received: from [199.232.76.173] (port=37260 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NILgr-0007L3-VN for qemu-devel@nongnu.org; Wed, 09 Dec 2009 07:30:45 -0500 Received: from mail-yw0-f183.google.com ([209.85.211.183]:38661) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NILgr-0003aB-OU for qemu-devel@nongnu.org; Wed, 09 Dec 2009 07:30:45 -0500 Received: by ywh13 with SMTP id 13so7224161ywh.29 for ; Wed, 09 Dec 2009 04:30:44 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: From: Artyom Tarasenko Date: Wed, 9 Dec 2009 13:30:24 +0100 Message-ID: Content-Type: text/plain; charset=ISO-8859-1 Subject: [Qemu-devel] Re: irq latency and tcg List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Blue Swirl Cc: qemu-devel 2009/12/7 Blue Swirl : > On Mon, Dec 7, 2009 at 3:30 PM, Artyom Tarasenko > wrote: >> Can it be that qemu (-system-sparc in my case, but I guess it's more >> or less similar on all platforms) reacts to irqs slower than a real >> hardware due to tcg optimizations? >> >> I see one test pattern which fails on qemu: >> >> >> nop * N >> >> >> What I observe is that the proper interrupt does take a place, but >> after the check, so no-one expects it anymore. >> Is there a way to reduce the interrupt latency? Or maybe there is a >> good substitute to a nop*N, so that irq would definitely get through >> in the mean time? > > On Sparc, nops do not generate any code at all. But "qemu: fatal: Raised interrupt while not in I/O function" is still a bug, right?