From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 890B8C77B7E for ; Thu, 27 Apr 2023 15:26:40 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ps3VW-0004QZ-J6; Thu, 27 Apr 2023 11:26:06 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ps3VL-0003xo-N3 for qemu-devel@nongnu.org; Thu, 27 Apr 2023 11:25:57 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ps3VH-0000h4-RO for qemu-devel@nongnu.org; Thu, 27 Apr 2023 11:25:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1682609150; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rScorxR86QO8djbo7rPv1Vb9/pJy/vzwZVQ656Hsqvo=; b=IqfHqD0Ya0v99R2e9IbamAdaubJeru3zAqEL6WjgL5I2O0MS40n0gV0MeH6o5PVg6HMmSQ PrXv407jxewfe0e3USO8vtAlXQDx4mSMkNA9mLtkMDF6Z95mZBP/pJi0W1N6xQFwRH5TK9 wgw8LOmXhl1CYtIdnRO7gTudo5A1ZRU= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-142-8zfLTTMaOhiIDsM9nYQIDQ-1; Thu, 27 Apr 2023 11:25:42 -0400 X-MC-Unique: 8zfLTTMaOhiIDsM9nYQIDQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 787EA10F98B1; Thu, 27 Apr 2023 15:23:33 +0000 (UTC) Received: from secure.mitica (unknown [10.39.193.238]) by smtp.corp.redhat.com (Postfix) with ESMTP id DBEEF40C2064; Thu, 27 Apr 2023 15:23:30 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, Marcel Apfelbaum , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Eric Blake , Juan Quintela , Peter Xu , John Snow , Yanan Wang , Stefan Hajnoczi , Leonardo Bras , Fam Zheng , Eduardo Habkost , Vladimir Sementsov-Ogievskiy , Richard Henderson Subject: [PULL 18/18] migration: Make dirty_bytes_last_sync atomic Date: Thu, 27 Apr 2023 17:22:34 +0200 Message-Id: <20230427152234.25400-19-quintela@redhat.com> In-Reply-To: <20230427152234.25400-1-quintela@redhat.com> References: <20230427152234.25400-1-quintela@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 Received-SPF: pass client-ip=170.10.133.124; envelope-from=quintela@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -22 X-Spam_score: -2.3 X-Spam_bar: -- X-Spam_report: (-2.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.171, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org As we set its value, it needs to be operated with atomics. We rename it from remaining to better reflect its meaning. Statistics always return the real reamaining bytes. This was used to store how much pages where dirty on the previous generation, so we can calculate the expected downtime as: dirty_bytes_last_sync / current_bandwith. If we use the actual remaining bytes, we would see a very small value at the end of the iteration. Signed-off-by: Juan Quintela Reviewed-by: Peter Xu Reviewed-by: Richard Henderson --- I am open to use ram_bytes_remaining() in its only use and be more "optimistic" about the downtime. Don't use __nocheck() functions. Use stat64_get() now that it exists. --- migration/migration.c | 3 ++- migration/ram.c | 2 +- migration/ram.h | 2 +- 3 files changed, 4 insertions(+), 3 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 9367bb2afc..abcadbb619 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2692,7 +2692,8 @@ static void migration_update_counters(MigrationState *s, */ if (stat64_get(&ram_counters.dirty_pages_rate) && transferred > 10000) { - s->expected_downtime = ram_counters.remaining / bandwidth; + s->expected_downtime = + stat64_get(&ram_counters.dirty_bytes_last_sync) / bandwidth; } qemu_file_reset_rate_limit(s->to_dst_file); diff --git a/migration/ram.c b/migration/ram.c index 5846f6e27f..89be3e3320 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1224,7 +1224,7 @@ static void migration_bitmap_sync(RAMState *rs) RAMBLOCK_FOREACH_NOT_IGNORED(block) { ramblock_sync_dirty_bitmap(rs, block); } - ram_counters.remaining = ram_bytes_remaining(); + stat64_set(&ram_counters.dirty_bytes_last_sync, ram_bytes_remaining()); } qemu_mutex_unlock(&rs->bitmap_mutex); diff --git a/migration/ram.h b/migration/ram.h index f189cc79f8..04b05e1b2c 100644 --- a/migration/ram.h +++ b/migration/ram.h @@ -41,6 +41,7 @@ * one thread). */ typedef struct { + Stat64 dirty_bytes_last_sync; Stat64 dirty_pages_rate; Stat64 dirty_sync_count; Stat64 dirty_sync_missed_zero_copy; @@ -51,7 +52,6 @@ typedef struct { Stat64 postcopy_bytes; Stat64 postcopy_requests; Stat64 precopy_bytes; - int64_t remaining; Stat64 transferred; } RAMStats; -- 2.40.0