From patchwork Fri Sep 6 11:13:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 13794037 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 518A9CE7B02 for ; Fri, 6 Sep 2024 11:25:17 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1smX0i-0004i6-MH; Fri, 06 Sep 2024 07:20:18 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1smX0P-0003pF-5t; Fri, 06 Sep 2024 07:20:01 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1smX0L-0008My-FX; Fri, 06 Sep 2024 07:19:56 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id D8A0F8C4B4; Fri, 6 Sep 2024 14:12:10 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id E557D13371D; Fri, 6 Sep 2024 14:13:28 +0300 (MSK) Received: (nullmailer pid 353765 invoked by uid 1000); Fri, 06 Sep 2024 11:13:25 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Nicholas Piggin , =?utf-8?q?A?= =?utf-8?q?lex_Benn=C3=A9e?= , Michael Tokarev Subject: [Stable-9.0.3 67/69] Revert "replay: stop us hanging in rr_wait_io_event" Date: Fri, 6 Sep 2024 14:13:16 +0300 Message-Id: <20240906111324.353230-67-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Nicholas Piggin This reverts commit 1f881ea4a444ef36a8b6907b0b82be4b3af253a2. That commit causes reverse_debugging.py test failures, and does not seem to solve the root cause of the problem x86-64 still hangs in record/replay tests. The problem with short-cutting the iowait that was taken during record phase is that related events will not get consumed at the same points (e.g., reading the clock). A hang with zero icount always seems to be a symptom of an earlier problem that has caused the recording to become out of synch with the execution and consumption of events by replay. Acked-by: Alex Bennée Signed-off-by: Nicholas Piggin Message-Id: <20240813050638.446172-6-npiggin@gmail.com> Signed-off-by: Alex Bennée Message-Id: <20240813202329.1237572-14-alex.bennee@linaro.org> (cherry picked from commit 94962ff00d09674047aed896e87ba09736cd6941) Signed-off-by: Michael Tokarev Fixes: https://gitlab.com/qemu-project/qemu/-/issues/2524 diff --git a/accel/tcg/tcg-accel-ops-rr.c b/accel/tcg/tcg-accel-ops-rr.c index 894e73e52c..a942442a33 100644 --- a/accel/tcg/tcg-accel-ops-rr.c +++ b/accel/tcg/tcg-accel-ops-rr.c @@ -109,7 +109,7 @@ static void rr_wait_io_event(void) { CPUState *cpu; - while (all_cpu_threads_idle() && replay_can_wait()) { + while (all_cpu_threads_idle()) { rr_stop_kick_timer(); qemu_cond_wait_bql(first_cpu->halt_cond); } diff --git a/include/sysemu/replay.h b/include/sysemu/replay.h index f229b2109c..8102fa54f0 100644 --- a/include/sysemu/replay.h +++ b/include/sysemu/replay.h @@ -73,11 +73,6 @@ int replay_get_instructions(void); /*! Updates instructions counter in replay mode. */ void replay_account_executed_instructions(void); -/** - * replay_can_wait: check if we should pause for wait-io - */ -bool replay_can_wait(void); - /* Processing clocks and other time sources */ /*! Save the specified clock */ diff --git a/replay/replay.c b/replay/replay.c index a2c576c16e..325e275756 100644 --- a/replay/replay.c +++ b/replay/replay.c @@ -449,27 +449,6 @@ void replay_start(void) replay_enable_events(); } -/* - * For none/record the answer is yes. - */ -bool replay_can_wait(void) -{ - if (replay_mode == REPLAY_MODE_PLAY) { - /* - * For playback we shouldn't ever be at a point we wait. If - * the instruction count has reached zero and we have an - * unconsumed event we should go around again and consume it. - */ - if (replay_state.instruction_count == 0 && replay_state.has_unread_data) { - return false; - } else { - replay_sync_error("Playback shouldn't have to iowait"); - } - } - return true; -} - - void replay_finish(void) { if (replay_mode == REPLAY_MODE_NONE) {