From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56711) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bhZnV-0001mZ-Mj for qemu-devel@nongnu.org; Wed, 07 Sep 2016 06:09:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bhZnO-0000ms-O1 for qemu-devel@nongnu.org; Wed, 07 Sep 2016 06:09:33 -0400 Received: from mail-wm0-x230.google.com ([2a00:1450:400c:c09::230]:35057) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bhZnO-0000mn-H7 for qemu-devel@nongnu.org; Wed, 07 Sep 2016 06:09:30 -0400 Received: by mail-wm0-x230.google.com with SMTP id i204so77544509wma.0 for ; Wed, 07 Sep 2016 03:09:30 -0700 (PDT) Sender: Paolo Bonzini References: <1470929064-4092-1-git-send-email-alex.bennee@linaro.org> <1470929064-4092-29-git-send-email-alex.bennee@linaro.org> From: Paolo Bonzini Message-ID: <09ce9021-32b4-63b5-0aaf-f1815eee40c5@redhat.com> Date: Wed, 7 Sep 2016 12:09:28 +0200 MIME-Version: 1.0 In-Reply-To: <1470929064-4092-29-git-send-email-alex.bennee@linaro.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [RFC v4 28/28] cputlb: make tlb_flush_by_mmuidx safe for MTTCG List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?UTF-8?Q?Alex_Benn=c3=a9e?= , mttcg@listserver.greensocs.com, qemu-devel@nongnu.org, fred.konrad@greensocs.com, a.rigo@virtualopensystems.com, cota@braap.org, bobby.prani@gmail.com, nikunj@linux.vnet.ibm.com Cc: peter.maydell@linaro.org, claudio.fontana@huawei.com, Peter Crosthwaite , jan.kiszka@siemens.com, mark.burton@greensocs.com, serge.fdrv@gmail.com, rth@twiddle.net On 11/08/2016 17:24, Alex Bennée wrote: > - if (atomic_bool_cmpxchg(&cpu->pending_tlb_flush, false, true)) { > + if (atomic_mb_read(&cpu->pending_tlb_flush) != ALL_MMUIDX_BITS) { > + atomic_mb_set(&cpu->pending_tlb_flush, ALL_MMUIDX_BITS); This can use atomic_xchg as well. atomic_bool_cmpxchg seems unnecessary then. (Not that I have anything against it, but there are no users yet :)). Paolo