From patchwork Tue Apr 6 22:11:09 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 49549 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id E14D2B7D5C for ; Wed, 7 Apr 2010 08:15:49 +1000 (EST) Received: from localhost ([127.0.0.1]:56231 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NzH0b-0000e4-22 for incoming@patchwork.ozlabs.org; Tue, 06 Apr 2010 18:12:33 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NzGzT-0000dn-3S for qemu-devel@nongnu.org; Tue, 06 Apr 2010 18:11:23 -0400 Received: from [140.186.70.92] (port=34163 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NzGzQ-0000dd-JC for qemu-devel@nongnu.org; Tue, 06 Apr 2010 18:11:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1NzGzL-0004Gc-14 for qemu-devel@nongnu.org; Tue, 06 Apr 2010 18:11:19 -0400 Received: from mail-fx0-f214.google.com ([209.85.220.214]:39305) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1NzGzK-0004GT-SU for qemu-devel@nongnu.org; Tue, 06 Apr 2010 18:11:14 -0400 Received: by fxm6 with SMTP id 6so453296fxm.17 for ; Tue, 06 Apr 2010 15:11:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:from:to:cc:subject :date:message-id:x-mailer:in-reply-to:references; bh=FS4HWaj86smsFrVVeeOdgIzsqUuh3vPLyip5ZC2uKio=; b=MUi/6472BDRbbYxZ7XaVHTtIO/jBqG8QtDvkIUSO3PRQ/8hEifAhaJJ+59sRjxGC6A vRJ/Nsh373NbTUcdvKQP4zqc7OJ7RMHF14dglexDfc+Fv4O2wG0zZvuqeY4SDMUGRBJG YuPn+c7rgHG81oaIKF+f8k9Q/GNFVI6IpmFAc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; b=IPfUDuoOUeCLT33cpepCoFv/2MWKrtbK7kP4jZ9URJWA6/gSnWQsFGwEc/y+TBFr99 cB/ZN6ETcQeHVLTA4az7+mYKFkFPq5y3lShqfPvCSvB/sDYB1hEmqukVVs7I0QHqCdrS TukEAjXa2VBg9E0JjGN0n5rLscR4fVXFmSaWM= Received: by 10.223.15.143 with SMTP id k15mr8071854faa.57.1270591873422; Tue, 06 Apr 2010 15:11:13 -0700 (PDT) Received: from localhost.localdomain (s209p8.home.99maxprogres.cz [85.93.118.17]) by mx.google.com with ESMTPS id 2sm562208fks.12.2010.04.06.15.11.12 (version=TLSv1/SSLv3 cipher=RC4-MD5); Tue, 06 Apr 2010 15:11:12 -0700 (PDT) From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Wed, 7 Apr 2010 00:11:09 +0200 Message-Id: <1270591869-11602-1-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.6.6.1 In-Reply-To: References: X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) Cc: Subject: [Qemu-devel] [PATCH resend] fix 100% cpu utilization when cpu is stopped X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org > Hello, > > d6f4ade (disentangle tcg and deadline calculation, 2010-03-10) > introduces following regression(s): > > 100% cpu utilization when QEMU is invoked like: > qemu -S -s ... > > ditto when gdb takes control over the session via gdb-stub > (i.e. the breakpoint is hit or C-c is pressed inside gdb to > interrupt the attached qemu instance) The bug is that env->stopped is not really as comprehensive as it seems to be (and cpu_has_work thinks); it is only valid with iothread basically, and even then it is cleared by reset and it is not set when starting qemu with -S. Signed-off-by: Paolo Bonzini Cc: malc --- cpus.c | 6 ++---- 1 files changed, 2 insertions(+), 4 deletions(-) diff --git a/cpus.c b/cpus.c index a2e0642..0debe77 100644 --- a/cpus.c +++ b/cpus.c @@ -100,9 +100,7 @@ static int cpu_can_run(CPUState *env) { if (env->stop) return 0; - if (env->stopped) - return 0; - if (!vm_running) + if (env->stopped || !vm_running) return 0; return 1; } @@ -111,7 +109,7 @@ static int cpu_has_work(CPUState *env) { if (env->stop) return 1; - if (env->stopped) + if (env->stopped || !vm_running) return 0; if (!env->halted) return 1;