From nobody Sat May 4 06:16:00 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1524042419302608.060098766617; Wed, 18 Apr 2018 02:06:59 -0700 (PDT) Received: from localhost ([::1]:42398 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f8j3K-000390-8q for importer@patchew.org; Wed, 18 Apr 2018 05:06:58 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54904) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f8iwc-0006PG-9w for qemu-devel@nongnu.org; Wed, 18 Apr 2018 05:00:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f8iwZ-0004Mt-93 for qemu-devel@nongnu.org; Wed, 18 Apr 2018 05:00:02 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:53148 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1f8iwZ-0004Mm-3Q for qemu-devel@nongnu.org; Wed, 18 Apr 2018 04:59:59 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A12838DC31 for ; Wed, 18 Apr 2018 08:59:58 +0000 (UTC) Received: from xz-mi.redhat.com (ovpn-12-25.pek2.redhat.com [10.72.12.25]) by smtp.corp.redhat.com (Postfix) with ESMTP id 101042166BAD; Wed, 18 Apr 2018 08:59:55 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Wed, 18 Apr 2018 16:59:54 +0800 Message-Id: <20180418085954.12582-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 18 Apr 2018 08:59:58 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 18 Apr 2018 08:59:58 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'peterx@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH] QemuMutex: support --enable-debug-mutex X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , Fam Zheng , Stefan Hajnoczi , peterx@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" We have had some tracing tools for mutex but it's not easy to use them for e.g. dead locks. Let's provide "--enable-debug-mutex" parameter when configure to allow QemuMutex to store the last owner that took specific lock. It might be extremely easy to use this tool to debug deadlocks since we can directly know who took the lock then as long as we can have a gdb attached to the process. CC: Paolo Bonzini CC: Stefan Hajnoczi CC: Fam Zheng Signed-off-by: Peter Xu --- configure | 10 ++++++++++ include/qemu/thread-posix.h | 4 ++++ util/qemu-thread-posix.c | 4 ++++ 3 files changed, 18 insertions(+) diff --git a/configure b/configure index 0a19b033bc..9ee1064c3b 100755 --- a/configure +++ b/configure @@ -451,6 +451,7 @@ jemalloc=3D"no" replication=3D"yes" vxhs=3D"" libxml2=3D"" +debug_mutex=3D"no" =20 supported_cpu=3D"no" supported_os=3D"no" @@ -1374,6 +1375,10 @@ for opt do ;; --disable-git-update) git_update=3Dno ;; + --enable-debug-mutex) debug_mutex=3Dyes + ;; + --disble-debug-mutex) debug_mutex=3Dyes + ;; *) echo "ERROR: unknown option $opt" echo "Try '$0 --help' for more information" @@ -1631,6 +1636,7 @@ disabled with --disable-FEATURE, default is enabled i= f available: crypto-afalg Linux AF_ALG crypto backend driver vhost-user vhost-user support capstone capstone disassembler support + debug-mutex mutex debugging support =20 NOTE: The object files are built at the place where configure is launched EOF @@ -5874,6 +5880,7 @@ echo "avx2 optimization $avx2_opt" echo "replication support $replication" echo "VxHS block device $vxhs" echo "capstone $capstone" +echo "mutex debugging $debug_mutex" =20 if test "$sdl_too_old" =3D "yes"; then echo "-> Your SDL version is too old - please upgrade to have SDL support" @@ -6602,6 +6609,9 @@ fi if test "$capstone" !=3D "no" ; then echo "CONFIG_CAPSTONE=3Dy" >> $config_host_mak fi +if test "$debug_mutex" =3D "yes" ; then + echo "CONFIG_DEBUG_MUTEX=3Dy" >> $config_host_mak +fi =20 # Hold two types of flag: # CONFIG_THREAD_SETNAME_BYTHREAD - we've got a way of setting the name = on diff --git a/include/qemu/thread-posix.h b/include/qemu/thread-posix.h index f3f47e426f..fd27b34128 100644 --- a/include/qemu/thread-posix.h +++ b/include/qemu/thread-posix.h @@ -12,6 +12,10 @@ typedef QemuMutex QemuRecMutex; =20 struct QemuMutex { pthread_mutex_t lock; +#ifdef CONFIG_DEBUG_MUTEX + const char *file; + int line; +#endif bool initialized; }; =20 diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c index b789cf32e9..905a816af6 100644 --- a/util/qemu-thread-posix.c +++ b/util/qemu-thread-posix.c @@ -68,6 +68,10 @@ void qemu_mutex_lock_impl(QemuMutex *mutex, const char *= file, const int line) if (err) error_exit(err, __func__); =20 +#ifdef CONFIG_DEBUG_MUTEX + mutex->file =3D file; + mutex->line =3D line; +#endif trace_qemu_mutex_locked(mutex, file, line); } =20 --=20 2.14.3