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 97ABDC77B61 for ; Mon, 24 Apr 2023 13:56:11 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pqwf3-0007zi-7h; Mon, 24 Apr 2023 09:55:21 -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 1pqwf1-0007xm-8e for qemu-devel@nongnu.org; Mon, 24 Apr 2023 09:55:19 -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 1pqwex-0006uo-Nq for qemu-devel@nongnu.org; Mon, 24 Apr 2023 09:55:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1682344515; 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=lPEpbxQ3Rxi6Db4jP64NwF7Y3HcVLA+BMKJOzh9iCak=; b=YAIFPXiF6f4VBqv+erW/gPdq9jxTQLU7XRKH/fCTOqX0m4P89UL5g4NVGrsK8em+N3Pnzw aYF9VLdOaWN6N4+ylflRI0AHbeiKiKNrNym1stkL2iIhWPSKamZOnWsoS5mtFIDZvJawkp rGCe+rmlcJXPIr7BG6JZIZDOJj8S6W0= 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-14-6hdwI2ndOMGdfh0z7s04TA-1; Mon, 24 Apr 2023 09:55:13 -0400 X-MC-Unique: 6hdwI2ndOMGdfh0z7s04TA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4C0FA38149A1 for ; Mon, 24 Apr 2023 13:55:13 +0000 (UTC) Received: from secure.mitica (unknown [10.39.192.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id 86E8E10DF8; Mon, 24 Apr 2023 13:55:12 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Cc: Juan Quintela , Peter Xu , Leonardo Bras Subject: [PATCH v4 2/2] migration: Make dirty_bytes_last_sync atomic Date: Mon, 24 Apr 2023 15:55:09 +0200 Message-Id: <20230424135509.71605-3-quintela@redhat.com> In-Reply-To: <20230424135509.71605-1-quintela@redhat.com> References: <20230424135509.71605-1-quintela@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 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 --- I am open to use ram_bytes_remaining() in its only use and be more "optimistic" about the downtime. Change aligned_uint64_t to size_t to make (some) 32bit hosts happy. --- 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 4cded4e0ae..1dd848015d 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -3183,7 +3183,9 @@ 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 e6f14023e4..3862ec0853 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1223,7 +1223,8 @@ 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 d7f534162d..801732ff13 100644 --- a/migration/ram.h +++ b/migration/ram.h @@ -41,6 +41,7 @@ * one thread). */ typedef struct { + size_t dirty_bytes_last_sync; size_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