From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59190) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dxSzL-0006Px-TW for qemu-devel@nongnu.org; Thu, 28 Sep 2017 03:12:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dxSzK-0002II-Tn for qemu-devel@nongnu.org; Thu, 28 Sep 2017 03:12:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50332) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dxSzK-0002I4-MF for qemu-devel@nongnu.org; Thu, 28 Sep 2017 03:12:02 -0400 Date: Thu, 28 Sep 2017 15:11:54 +0800 From: Fam Zheng Message-ID: <20170928071154.GC26066@lemon.lan> References: <20170928025958.1420-1-peterx@redhat.com> <20170928025958.1420-6-peterx@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170928025958.1420-6-peterx@redhat.com> Subject: Re: [Qemu-devel] [PATCH v4 5/5] aio: fix assert when remove poll during destroy List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Xu Cc: qemu-devel@nongnu.org, Paolo Bonzini , "Daniel P . Berrange" , Stefan Hajnoczi , Andreas =?iso-8859-1?Q?F=E4rber?= , Manos Pitsidianakis , "Dr . David Alan Gilbert" , Stefan Hajnoczi On Thu, 09/28 10:59, Peter Xu wrote: > From: Stefan Hajnoczi > > After iothread is enabled internally inside QEMU with GMainContext, we > may encounter this warning when destroying the iothread: > > (qemu-system-x86_64:19925): GLib-CRITICAL **: g_source_remove_poll: > assertion '!SOURCE_DESTROYED (source)' failed > > The problem is that g_source_remove_poll() does not allow to remove one > source from array if the source is detached from its owner > context. (peterx: which IMHO does not make much sense) > > Fix it on QEMU side by avoid calling g_source_remove_poll() if we know > the object is during destruction, and we won't leak anything after all > since the array will be gone soon cleanly even with that fd. > > Signed-off-by: Stefan Hajnoczi > [peterx: write the commit message] > Signed-off-by: Peter Xu > --- > util/aio-posix.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/util/aio-posix.c b/util/aio-posix.c > index 2d51239ec6..5946ac09f0 100644 > --- a/util/aio-posix.c > +++ b/util/aio-posix.c > @@ -223,7 +223,14 @@ void aio_set_fd_handler(AioContext *ctx, > return; > } > > - g_source_remove_poll(&ctx->source, &node->pfd); > + /* If the GSource is in the process of being destroyed then > + * g_source_remove_poll() causes an assertion failure. Skip > + * removal in that case, because glib cleans up its state during > + * destruction anyway. > + */ > + if (!g_source_is_destroyed(&ctx->source)) { > + g_source_remove_poll(&ctx->source, &node->pfd); > + } > > /* If the lock is held, just mark the node as deleted */ > if (qemu_lockcnt_count(&ctx->list_lock)) { > -- > 2.13.5 > Reviewed-by: Fam Zheng