From patchwork Mon Mar 29 07:59:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Dovgalyuk X-Patchwork-Id: 12169711 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 78173C433DB for ; Mon, 29 Mar 2021 08:00:24 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4D8706196F for ; Mon, 29 Mar 2021 08:00:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4D8706196F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=ispras.ru Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:43788 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lQmow-0001Hh-5C for qemu-devel@archiver.kernel.org; Mon, 29 Mar 2021 04:00:22 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59896) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lQmoC-0000pd-FY for qemu-devel@nongnu.org; Mon, 29 Mar 2021 03:59:36 -0400 Received: from mail.ispras.ru ([83.149.199.84]:56664) by eggs.gnu.org with esmtps (TLS1.2:DHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lQmoA-0005X4-8b for qemu-devel@nongnu.org; Mon, 29 Mar 2021 03:59:36 -0400 Received: from [127.0.1.1] (unknown [62.118.151.149]) by mail.ispras.ru (Postfix) with ESMTPSA id 55E3C40755CC; Mon, 29 Mar 2021 07:59:25 +0000 (UTC) Subject: [PATCH] replay: fix recursive checkpoints From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Mon, 29 Mar 2021 10:59:25 +0300 Message-ID: <161700476500.1140362.10108444973730452257.stgit@pasha-ThinkPad-X280> User-Agent: StGit/0.23 MIME-Version: 1.0 Received-SPF: pass client-ip=83.149.199.84; envelope-from=pavel.dovgalyuk@ispras.ru; helo=mail.ispras.ru X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: alex.bennee@linaro.org, pbonzini@redhat.com, pavel.dovgalyuk@ispras.ru Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Record/replay uses checkpoints to synchronize the execution of the threads and timers. Hardware events such as BH are processed at the checkpoints too. Event processing can cause refreshing the virtual timers and calling the icount-related functions, that also use checkpoints. This patch prevents recursive processing of such checkpoints, because they have their own records in the log and should be processed later. Signed-off-by: Pavel Dovgalyuk --- replay/replay.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/replay/replay.c b/replay/replay.c index c806fec69a..6df2abc18c 100644 --- a/replay/replay.c +++ b/replay/replay.c @@ -180,12 +180,13 @@ bool replay_checkpoint(ReplayCheckpoint checkpoint) } if (in_checkpoint) { - /* If we are already in checkpoint, then there is no need - for additional synchronization. + /* Recursion occurs when HW event modifies timers. - Timer modification may invoke the checkpoint and - proceed to recursion. */ - return true; + Prevent performing icount warp in this case and + wait for another invocation of the checkpoint. + */ + g_assert(replay_mode == REPLAY_MODE_PLAY); + return false; } in_checkpoint = true;