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 CDF37C77B72 for ; Thu, 20 Apr 2023 13:22:44 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ppUB7-0001pk-OC; Thu, 20 Apr 2023 09:18:25 -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 1ppUAt-0001VT-Fx for qemu-devel@nongnu.org; Thu, 20 Apr 2023 09:18:13 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ppUAr-0005fY-KD for qemu-devel@nongnu.org; Thu, 20 Apr 2023 09:18:10 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1681996689; 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=fpIe2fggh0WgGhk7dw5U2PA0cF4YjoQLtGpttx1vF90=; b=Wxn6qspExtOMtUav+PktwGfW0udwM/LL4yEC0uz/ipn1OwHrIwFPDT3p/EP8BBPSc9Ux4g eWogG0KIo1Rjr7hhovicqL/tHhikE6pFyn712lXtBQ8tsSnTjpPHH+hgYDMX55W8zA7hqF ROWBAOli9myTwrJ9oRWM4jow4H6OQ+c= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-583-TTduI9KZNmqLZMlS9lSMzg-1; Thu, 20 Apr 2023 09:18:07 -0400 X-MC-Unique: TTduI9KZNmqLZMlS9lSMzg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4BDDD29AA39B for ; Thu, 20 Apr 2023 13:18:07 +0000 (UTC) Received: from secure.mitica (unknown [10.39.192.171]) by smtp.corp.redhat.com (Postfix) with ESMTP id B5641C16024; Thu, 20 Apr 2023 13:18:05 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Cc: Juan Quintela , Paolo Bonzini , Peter Xu Subject: [PULL 12/20] migration: Make dirty_bytes_last_sync atomic Date: Thu, 20 Apr 2023 15:17:43 +0200 Message-Id: <20230420131751.28534-13-quintela@redhat.com> In-Reply-To: <20230420131751.28534-1-quintela@redhat.com> References: <20230420131751.28534-1-quintela@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.129.124; envelope-from=quintela@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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 --- I am open to use ram_bytes_remaining() in its only use and be more "optimistic" about the downtime. --- migration/migration.c | 4 +++- migration/ram.c | 3 ++- migration/ram.h | 2 +- 3 files changed, 6 insertions(+), 3 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 50eae2fbcd..83d3bfbf62 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -3847,7 +3847,9 @@ static void migration_update_counters(MigrationState *s, */ if (qatomic_read__nocheck(&ram_counters.dirty_pages_rate) && transferred > 10000) { - s->expected_downtime = ram_counters.remaining / bandwidth; + s->expected_downtime = + qatomic_read__nocheck(&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 7400abf5e1..7bbaf8cd86 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1224,7 +1224,8 @@ static void migration_bitmap_sync(RAMState *rs) RAMBLOCK_FOREACH_NOT_IGNORED(block) { ramblock_sync_dirty_bitmap(rs, block); } - ram_counters.remaining = ram_bytes_remaining(); + qatomic_set__nocheck(&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 574a604b72..8093ebc210 100644 --- a/migration/ram.h +++ b/migration/ram.h @@ -41,6 +41,7 @@ * one thread). */ typedef struct { + aligned_uint64_t dirty_bytes_last_sync; aligned_uint64_t 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; -- 2.39.2