From patchwork Fri Aug 2 10:18:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ivan Ren X-Patchwork-Id: 11073099 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CFB861398 for ; Fri, 2 Aug 2019 10:19:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B717F287D1 for ; Fri, 2 Aug 2019 10:19:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A6EE8287E2; Fri, 2 Aug 2019 10:19:20 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.0 required=2.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 1F014287D1 for ; Fri, 2 Aug 2019 10:19:20 +0000 (UTC) Received: from localhost ([::1]:33232 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1htUed-0001KN-AL for patchwork-qemu-devel@patchwork.kernel.org; Fri, 02 Aug 2019 06:19:19 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35251) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1htUeB-0000uD-Hr for qemu-devel@nongnu.org; Fri, 02 Aug 2019 06:18:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1htUeA-0002ik-9j for qemu-devel@nongnu.org; Fri, 02 Aug 2019 06:18:51 -0400 Received: from mail-pg1-x542.google.com ([2607:f8b0:4864:20::542]:36232) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1htUeA-0002iM-3T for qemu-devel@nongnu.org; Fri, 02 Aug 2019 06:18:50 -0400 Received: by mail-pg1-x542.google.com with SMTP id l21so35842125pgm.3 for ; Fri, 02 Aug 2019 03:18:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=kQu6m9ey+QzJckmUlXYBq5skDhJZphPeYRk2B18xjGk=; b=bZjWEjhQvjabaCgLNI/4Z5Ghe//PI+tuxw27IYG0oNiSLc1JVOeXzKbOqtWwCQhB/5 fVKqKTyGxxD8jchhavW/OYdIdjW8tS7pVc2kvRKEYM7psdGhGpHAmTuxNpuOqDdBMhD9 3PQNh/DOIRbqZdGAcSABdXgtAj/8fx2HjXp3b6opI6pbJeygMXzqNNMZ1osQqCsxv96O vj+YLZpOOtG2/v9eoek7kHPA2mNMjXlVmUq1EMDCG1B3ITFjMdv9WYlWzAX+erL5DHAg Q6bSO1vSgP48krkTW17Ttm571lI7RbW/zIln+erLVDjaqYdrrqIKs9rSwN+21OfET/qp hiBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=kQu6m9ey+QzJckmUlXYBq5skDhJZphPeYRk2B18xjGk=; b=a8jW6aqNSaiznpmEZoxjKuQSEG1sKGGwZ/XqXUt0d016QlGNREYtpUdP8NbFfXHwiz aDSNQRUKqR4L3D7xWLwqTlGqocDtUUAMeepkBW7jJE3WGHppjs3/N4mmpWh8t/HVVxn0 kARRR7Zil1epeLvIuhBNo0An8tckC92YDlPEWC7GbiRVUcDIDwjY51kHwVc91KiDiTmx NpzJ1TBK3/f3qz6tRI80H6HFWuNL2Iy1E0oDDAmx7aFb5Y5HOuvcmTDNBYNcIFQ3221D LlNtIYDMD/YYXF5ewRIgLL9Qg3SZL7xTxdU0u1xr7htJznD90jKkE9CXw9aDiz7HwXc/ QL9Q== X-Gm-Message-State: APjAAAVQmwtoUCpymajYGeKuynzReaCx9tRKzPMe/yC/4qieGGKhXbZ0 UaAGPJtRVg1GVgHlxerHEZg= X-Google-Smtp-Source: APXvYqzTmmSBGiVxKEDubXi5F0z/qB+BZw7FyH88Htv+yThl0BwBdHs0O2BwH0e4dY4cjrBON2t3ng== X-Received: by 2002:a65:4103:: with SMTP id w3mr104954718pgp.1.1564741129014; Fri, 02 Aug 2019 03:18:49 -0700 (PDT) Received: from VM_85_204_centos.localdomain ([129.226.55.250]) by smtp.gmail.com with ESMTPSA id d8sm68625412pgh.45.2019.08.02.03.18.47 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 02 Aug 2019 03:18:48 -0700 (PDT) From: Ivan Ren X-Google-Original-From: Ivan Ren To: quintela@redhat.com, dgilbert@redhat.com Date: Fri, 2 Aug 2019 18:18:41 +0800 Message-Id: <1564741121-1840-1-git-send-email-ivanren@tencent.com> X-Mailer: git-send-email 1.8.3.1 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:4864:20::542 Subject: [Qemu-devel] [PATCH v3] migration: always initial ram_counters for a new migration X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: richardw.yang@linux.intel.com, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Ivan Ren This patch fix a multifd migration bug in migration speed calculation, this problem can be reproduced as follows: 1. start a vm and give a heavy memory write stress to prevent the vm be successfully migrated to destination 2. begin a migration with multifd 3. migrate for a long time [actually, this can be measured by transferred bytes] 4. migrate cancel 5. begin a new migration with multifd, the migration will directly run into migration_completion phase Reason as follows: Migration update bandwidth and s->threshold_size in function migration_update_counters after BUFFER_DELAY time: current_bytes = migration_total_bytes(s); transferred = current_bytes - s->iteration_initial_bytes; time_spent = current_time - s->iteration_start_time; bandwidth = (double)transferred / time_spent; s->threshold_size = bandwidth * s->parameters.downtime_limit; In multifd migration, migration_total_bytes function return qemu_ftell(s->to_dst_file) + ram_counters.multifd_bytes. s->iteration_initial_bytes will be initialized to 0 at every new migration, but ram_counters is a global variable, and history migration data will be accumulated. So if the ram_counters.multifd_bytes is big enough, it may lead pending_size >= s->threshold_size become false in migration_iteration_run after the first migration_update_counters. Signed-off-by: Ivan Ren Reviewed-by: Juan Quintela Suggested-by: Wei Yang Reviewed-by: Wei Yang --- v2->v3: - fix the bug of update_iteration_initial_status function prototype v1->v2: - Add interface update_iteration_initial_status to update statistic fields at the same time to avoid info mismatch lead wrong calculation result. migration/migration.c | 25 +++++++++++++++++++------ migration/savevm.c | 1 + 2 files changed, 20 insertions(+), 6 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 8a607fe1e2..bea9b1d796 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1908,6 +1908,11 @@ static bool migrate_prepare(MigrationState *s, bool blk, bool blk_inc, } migrate_init(s); + /* + * set ram_counters memory to zero for a + * new migration + */ + memset(&ram_counters, 0, sizeof(ram_counters)); return true; } @@ -3025,6 +3030,17 @@ static void migration_calculate_complete(MigrationState *s) } } +static void update_iteration_initial_status(MigrationState *s) +{ + /* + * Update these three fields at the same time to avoid mismatch info lead + * wrong speed calculation. + */ + s->iteration_start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + s->iteration_initial_bytes = migration_total_bytes(s); + s->iteration_initial_pages = ram_get_total_transferred_pages(); +} + static void migration_update_counters(MigrationState *s, int64_t current_time) { @@ -3060,9 +3076,7 @@ static void migration_update_counters(MigrationState *s, qemu_file_reset_rate_limit(s->to_dst_file); - s->iteration_start_time = current_time; - s->iteration_initial_bytes = current_bytes; - s->iteration_initial_pages = ram_get_total_transferred_pages(); + update_iteration_initial_status(s); trace_migrate_transferred(transferred, time_spent, bandwidth, s->threshold_size); @@ -3186,7 +3200,7 @@ static void *migration_thread(void *opaque) rcu_register_thread(); object_ref(OBJECT(s)); - s->iteration_start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + update_iteration_initial_status(s); qemu_savevm_state_header(s->to_dst_file); @@ -3251,8 +3265,7 @@ static void *migration_thread(void *opaque) * the local variables. This is important to avoid * breaking transferred_bytes and bandwidth calculation */ - s->iteration_start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); - s->iteration_initial_bytes = 0; + update_iteration_initial_status(s); } current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); diff --git a/migration/savevm.c b/migration/savevm.c index 79ed44d475..480c511b19 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -1424,6 +1424,7 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp) } migrate_init(ms); + memset(&ram_counters, 0, sizeof(ram_counters)); ms->to_dst_file = f; qemu_mutex_unlock_iothread();