From patchwork Wed Oct 4 08:01:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 1843043 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4S0nQ05CZCz20Zl for ; Wed, 4 Oct 2023 19:08:40 +1100 (AEDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qnwu5-0006J1-FX; Wed, 04 Oct 2023 04:06:46 -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 1qnwtW-00060L-Vf; Wed, 04 Oct 2023 04:06:16 -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 1qnwtR-0003hU-6H; Wed, 04 Oct 2023 04:06:08 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id BA426275B3; Wed, 4 Oct 2023 11:02:30 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id 0E32F2CBEC; Wed, 4 Oct 2023 11:02:30 +0300 (MSK) Received: (nullmailer pid 2702865 invoked by uid 1000); Wed, 04 Oct 2023 08:02:22 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Richard Henderson , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , Michael Tokarev Subject: [Stable-8.1.2 38/45] accel/tcg: Improve setting of can_do_io at start of TB Date: Wed, 4 Oct 2023 11:01:59 +0300 Message-Id: <20231004080221.2702636-38-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 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Richard Henderson Initialize can_do_io to true if this the TB has CF_LAST_IO and will consist of a single instruction. This avoids a set to 0 followed immediately by a set to 1. Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson (cherry picked from commit a2f99d484c54adda13e62bf75ba512618a3fe470) Signed-off-by: Michael Tokarev diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c index 850d82e26f..dd507cd471 100644 --- a/accel/tcg/translator.c +++ b/accel/tcg/translator.c @@ -87,12 +87,12 @@ static TCGOp *gen_tb_start(DisasContextBase *db, uint32_t cflags) offsetof(ArchCPU, neg.icount_decr.u16.low) - offsetof(ArchCPU, env)); /* - * cpu->can_do_io is cleared automatically here at the beginning of + * cpu->can_do_io is set automatically here at the beginning of * each translation block. The cost is minimal and only paid for * -icount, plus it would be very easy to forget doing it in the * translator. */ - set_can_do_io(db, false); + set_can_do_io(db, db->max_insns == 1 && (cflags & CF_LAST_IO)); } return icount_start_insn;