From patchwork Mon Jan 18 05:40:18 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Congyang X-Patchwork-Id: 8052741 Return-Path: X-Original-To: patchwork-xen-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 0CF479F859 for ; Mon, 18 Jan 2016 05:43:37 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 281792022A for ; Mon, 18 Jan 2016 05:43:36 +0000 (UTC) Received: from lists.xen.org (lists.xenproject.org [50.57.142.19]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 359E42020F for ; Mon, 18 Jan 2016 05:43:35 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xen.org) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aL2Y8-0000wV-Sy; Mon, 18 Jan 2016 05:40:20 +0000 Received: from mail6.bemta4.messagelabs.com ([85.158.143.247]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aL2Y7-0000w2-Cu for xen-devel@lists.xen.org; Mon, 18 Jan 2016 05:40:19 +0000 Received: from [85.158.143.35] by server-3.bemta-4.messagelabs.com id 47/41-31122-2CA7C965; Mon, 18 Jan 2016 05:40:18 +0000 X-Env-Sender: wency@cn.fujitsu.com X-Msg-Ref: server-5.tower-21.messagelabs.com!1453095616!10624662!1 X-Originating-IP: [59.151.112.132] X-SpamReason: No, hits=0.0 required=7.0 tests= X-StarScan-Received: X-StarScan-Version: 7.35.1; banners=-,-,- X-VirusChecked: Checked Received: (qmail 47113 invoked from network); 18 Jan 2016 05:40:17 -0000 Received: from cn.fujitsu.com (HELO heian.cn.fujitsu.com) (59.151.112.132) by server-5.tower-21.messagelabs.com with SMTP; 18 Jan 2016 05:40:17 -0000 X-IronPort-AV: E=Sophos;i="5.20,346,1444665600"; d="scan'208";a="2691052" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 18 Jan 2016 13:40:13 +0800 Received: from G08CNEXCHPEKD01.g08.fujitsu.local (unknown [10.167.33.80]) by cn.fujitsu.com (Postfix) with ESMTP id 4619A41896C3; Mon, 18 Jan 2016 13:40:00 +0800 (CST) Received: from G08FNSTD140052.g08.fujitsu.local (10.167.226.52) by G08CNEXCHPEKD01.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.181.6; Mon, 18 Jan 2016 13:39:59 +0800 From: Wen Congyang To: xen devel , Andrew Cooper Date: Mon, 18 Jan 2016 13:40:18 +0800 Message-ID: <1453095622-14859-2-git-send-email-wency@cn.fujitsu.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1453095622-14859-1-git-send-email-wency@cn.fujitsu.com> References: <1453095622-14859-1-git-send-email-wency@cn.fujitsu.com> MIME-Version: 1.0 X-Originating-IP: [10.167.226.52] X-yoursite-MailScanner-ID: 4619A41896C3.A5736 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: wency@cn.fujitsu.com X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Cc: Changlong Xie , Wei Liu , Ian Campbell , Wen Congyang , Ian Jackson , Shriram Rajagopalan , Yang Hongyang Subject: [Xen-devel] [PATCH v4 1/5] remus: don't call stream_continue() when doing failover X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP stream_continue() is used for migration to read emulator xenstore data and emulator context. For remus, if we do failover, we have read it in the checkpoint cycle, and we only need to complete the stream. Signed-off-by: Wen Congyang Reviewed-by: Andrew Cooper --- tools/libxl/libxl_stream_read.c | 35 ++++++++++++++++++++++++++++++----- 1 file changed, 30 insertions(+), 5 deletions(-) diff --git a/tools/libxl/libxl_stream_read.c b/tools/libxl/libxl_stream_read.c index 258dec4..24305f4 100644 --- a/tools/libxl/libxl_stream_read.c +++ b/tools/libxl/libxl_stream_read.c @@ -101,6 +101,19 @@ * - stream_write_emulator_done() * - stream_continue() * + * 4) Failover for remus + * - we buffer all records until a CHECKPOINT_END record is received + * - we will use the records when a CHECKPOINT_END record is received + * - if we find some internal error, the rc or retval is not 0 in + * libxl__xc_domain_restore_done(). In this case, we don't resume the + * guest + * - if we need to do failover from primary, the rc and retval are 0 + * in libxl__xc_domain_restore_done(). In this case, the buffered state + * will be dropped, because we don't receive a CHECKPOINT_END record, + * and it is a inconsistent state. In libxl__xc_domain_restore_done(), + * we just complete the stream and stream->completion_callback() will + * be called to resume the guest + * * Depending on the contents of the stream, there are likely to be several * parallel tasks being managed. check_all_finished() is used to join all * tasks in both success and error cases. @@ -758,6 +771,9 @@ void libxl__xc_domain_restore_done(libxl__egc *egc, void *dcs_void, libxl__stream_read_state *stream = &dcs->srs; STATE_AO_GC(dcs->ao); + /* convenience aliases */ + const int checkpointed_stream = dcs->restore_params.checkpointed_stream; + if (rc) goto err; @@ -777,11 +793,20 @@ void libxl__xc_domain_restore_done(libxl__egc *egc, void *dcs_void, * If the stream is not still alive, we must not continue any work. */ if (libxl__stream_read_inuse(stream)) { - /* - * Libxc has indicated that it is done with the stream. Resume reading - * libxl records from it. - */ - stream_continue(egc, stream); + if (checkpointed_stream) { + /* + * Failover from primary. Domain state is currently at a + * consistent checkpoint, complete the stream, and call + * stream->completion_callback() to resume the guest. + */ + stream_complete(egc, stream, 0); + } else { + /* + * Libxc has indicated that it is done with the stream. + * Resume reading libxl records from it. + */ + stream_continue(egc, stream); + } } }