From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51543) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dwW4t-0003fK-9B for qemu-devel@nongnu.org; Mon, 25 Sep 2017 12:17:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dwW4q-0006xx-2j for qemu-devel@nongnu.org; Mon, 25 Sep 2017 12:17:51 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:54313) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dwW4p-0006xG-S0 for qemu-devel@nongnu.org; Mon, 25 Sep 2017 12:17:48 -0400 Date: Fri, 22 Sep 2017 16:40:18 -0400 From: "Emilio G. Cota" Message-ID: <20170922204018.GA23631@flamenco> References: <1500616763-26560-1-git-send-email-cota@braap.org> <1500616763-26560-2-git-send-email-cota@braap.org> <20170829211649.GA9108@flamenco> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH v4 11/43] tcg: define CF_PARALLEL and use it for TB hashing along with CF_COUNT_MASK List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Richard Henderson Cc: Pranith Kumar , qemu-devel Hi Richard, Are you planning to get this patchset merged in this window? If so, I can give it a respin on top of the current master. Anyway, before doing so we should fix the issue around CF_COUNT_MASK that Pranith reported: On Wed, Aug 30, 2017 at 10:43:28 -0400, Pranith Kumar wrote: > On Tue, Aug 29, 2017 at 5:16 PM, Emilio G. Cota wrote: > > On Sun, Aug 27, 2017 at 18:15:50 -0400, Pranith Kumar wrote: > >> Hi Emilio, > >> > >> On Fri, Jul 21, 2017 at 1:59 AM, Emilio G. Cota wrote: > >> > This will enable us to decouple code translation from the value > >> > of parallel_cpus at any given time. It will also help us minimize > >> > TB flushes when generating code via EXCP_ATOMIC. > >> > > >> > Note that the declaration of parallel_cpus is brought to exec-all.h > >> > to be able to define there the "curr_cflags" inline. > >> > > >> > Signed-off-by: Emilio G. Cota > >> > >> I was testing a winxp image today and I bisected a infinite loop to > >> this commit. The loop happens both with and without mttcg, so I think > >> it has got to do with something else. > > > > Can you test the below? It lets me boot ubuntu, otherwise it reliably > > chokes on a 'rep movsb' *very* early (doesn't even get to grub). > > > > This discusson on v2 might be relevant (I added CF_COUNT_MASK as a > > result of it, but it seems I have to revisit that): > > https://lists.gnu.org/archive/html/qemu-devel/2017-07/msg06456.html > > > > Anyway let me know if this fixes it for you. Thanks for testing! > > > > Yes, this fixes the issue for me. My quick-fix is just not to check those bits, but as you pointed out during v3's review the whole thing is a little bit fragile if we don't check them. Should we just go with the CF_NOCHAIN flag that you proposed? If so, do you want me to give that approach a go, or you prefer to do it yourself? Thanks, Emilio