From patchwork Wed May 9 22:14:25 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kiszka X-Patchwork-Id: 158053 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 8B289B6F62 for ; Thu, 10 May 2012 08:14:43 +1000 (EST) Received: from localhost ([::1]:42556 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SSF9d-0005E9-BQ for incoming@patchwork.ozlabs.org; Wed, 09 May 2012 18:14:41 -0400 Received: from eggs.gnu.org ([208.118.235.92]:38472) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SSF9X-0005E3-7J for qemu-devel@nongnu.org; Wed, 09 May 2012 18:14:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SSF9V-0004Zi-Ib for qemu-devel@nongnu.org; Wed, 09 May 2012 18:14:34 -0400 Received: from thoth.sbs.de ([192.35.17.2]:31270) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SSF9V-0004YO-8x for qemu-devel@nongnu.org; Wed, 09 May 2012 18:14:33 -0400 Received: from mail1.siemens.de (localhost [127.0.0.1]) by thoth.sbs.de (8.13.6/8.13.6) with ESMTP id q49METV3020749; Thu, 10 May 2012 00:14:29 +0200 Received: from mchn199C.mchp.siemens.de ([139.22.46.144]) by mail1.siemens.de (8.13.6/8.13.6) with SMTP id q49MEQM0010266; Thu, 10 May 2012 00:14:27 +0200 Message-ID: <4FAAEC41.70608@siemens.com> Date: Wed, 09 May 2012 19:14:25 -0300 From: Jan Kiszka User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 MIME-Version: 1.0 To: qemu-devel , Anthony Liguori X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6, seldom 2.4 (older, 4) X-Received-From: 192.35.17.2 Cc: Kevin Wolf , Peter Maydell , Michael Tokarev , Avi Kivity Subject: [Qemu-devel] [PATCH 1.1] Switch SIG_IPI to SIGUSR1 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 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 Use SIGUSR1 unconditionally as SIG_IPI. First, ucontext coroutines tend to corrupt RT signal masks due to a 32-on-64-bit Linux kernel bug. And, second, there appears to be no advantage in using RT signals for VCPU kicking. Signed-off-by: Jan Kiszka --- As people prefer to stick with ucontext, this replaces the backend switch for i386-linux. Avi, you once committed the RT signal based SIG_IPI version to qemu-kvm. Can you confirm that SIGUSR1 comes with no downside? This is also stable material. main-loop.h | 4 ---- 1 files changed, 0 insertions(+), 4 deletions(-) diff --git a/main-loop.h b/main-loop.h index c06b8bc..dce1cd9 100644 --- a/main-loop.h +++ b/main-loop.h @@ -25,11 +25,7 @@ #ifndef QEMU_MAIN_LOOP_H #define QEMU_MAIN_LOOP_H 1 -#ifdef SIGRTMIN -#define SIG_IPI (SIGRTMIN+4) -#else #define SIG_IPI SIGUSR1 -#endif /** * qemu_init_main_loop: Set up the process so that it can run the main loop.